3406B (PEEC) PROGRAMMABLE ELECTRONIC ENGINE CONTROLS Caterpillar

These tests are designed to establish whether a component and related parts are working properly, and if not, to pinpoint the faulty component.

These tests may also be used for basic health checks, to determine if problems exist, or as a guide to check for intermittent problems.

P-201: Inspecting Electrical Connectors

Many of the Operational Procedures and Diagnostic Code Procedures in this troubleshooting guide will direct you to check a specific electrical connector. Use the following steps to help determine if the connector is the cause of the problem. If a problem is found in the electrical connector, repair the connector and continue the test procedure.

1. Check connector lock ring.

Make sure that connector was properly locked and that the lock ring is capable of locking connector together.

2. Perform 10 pound pull test on each pin/wire.

Each pin and connector should easily withstand 10 pounds of pull, and remain in the connector body. This test checks whether the wire was properly crimped in the pin, and whether the pin was properly inserted into the connector. Repair as needed.

NOTE: Any time a wire is removed from a connector for testing purposes, do a 10 pound pull test after reinserting the wire.

NOTE: Pins should ALWAYS be crimped onto the wires; NEVER soldered. Use 1U5804 Crimping Tool (part of 4C3406 Connector Repair Kit).

3. Visually inspect wiring.

Look for worn or abraded wires. Check for pinched or damaged harnesses, especially on OEM wiring and early PEEC engines.

4. Visually inspect connectors.

Verify that pins and sockets are not corroded or damaged. Verify proper alignment and location of pins in the connector.

5. Check individual pins and sockets.

This is especially important for intermittent problems. Using a new pin, insert the pin into each socket one at a time to check for a good grip on the pin by the socket. Repeat for each pin on the mating side of the connector, using a new socket for the test.

P-210: Electrical Power Supply To PEEC Test

The PEEC ECM receives electrical power (battery voltage) through wiring supplied by the vehicle manufacturer. In typical applications, PEEC receives power whenever the key is turned on.

Some vehicles may be equipped with an engine protection shutdown system (such as a Kysor or Vigil shutdown system) or an idle time shutdown system (external to PEEC) that interrupts electrical power to the ECM to shut the engine down. Some of these will not supply power to PEEC until the engine is cranked, until oil pressure comes up to acceptable limits, or until an override button is pressed. Keep in mind that these devices may be the cause of no (or intermittent) power to the ECM.

This procedure tests whether proper voltage is being supplied by the vehicle wiring. Detailed tests to identify specific failures in the vehicle wiring are the responsibility of the vehicle manufacturer.

Note that the ECAP or DDT is supplied with electrical power through direct connections inside the ECM. Therefore, if the ECAP or DDT has power, so does the ECM.

For intermittent problems that could be caused by vehicle wiring (such as intermittent shutdowns), temporarily bypassing the vehicle wiring may be an effective means of determining the root cause. If symptoms vanish with the wiring bypassed, vehicle wiring was the cause. A means of bypassing vehicle wiring is explained below.

Step 1. Check Electrical Connectors And Wiring

Check vehicle connector (J2/P2) and battery power and grounds to J2/P2, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

* Visually and physically check grounds for looseness or corrosion. If a problem is found, disconnect, clean, and reconnect the connector

Step 2. Check Battery Voltage Coming To ECM

A. Connect a 9-pin 'T' at the ECM vehicle connector (J2/P2).

B. Turn key ON, engine OFF.

C. Measure the voltage between + Battery (Pin A) and ground (Pin B).

The voltage at Pin A should be between 11.5 and 13.5 VDC.

OK: The ECM is currently receiving the correct voltage. If intermittent problems with battery voltage may be occurring, consider temporarily bypassing vehicle wiring as shown in Step 4. Otherwise, Stop.

NOT OK: The ECM is NOT receiving the correct voltages. Continue with the next step.

Step 3. Check Batteries

A. Measure battery voltage at the battery posts.

B. Load test the batteries using the 4C4911 Battery Load Tester. Make reference to Operation Manual, Form No. SEHS9249 for more complete information for use of the 6V4930 Battery Load Tester.

The voltage at the batteries should be at least 11.5 VDC, and the batteries should pass the load test.

OK: The batteries are not the problem. Wiring or components between the batteries and PEEC are preventing voltage from reaching PEEC. Refer to the service manual for the vehicle for instructions on how to troubleshoot the vehicle wiring. Stop.

NOT OK: The batteries are defective. Replace the defective batteries. Stop.

Step 4. Bypass Vehicle Wiring For Testing

NOTE: This bypass is for TEST PURPOSES ONLY. It may be left on the vehicle temporarily to test whether intermittent problems are due to interruptions in battery power to the ECM. Since this will also bypass any engine protection devices, obtain approval from the owner before releasing a truck with this bypass installed. The bypass switch is installed in parallel with the ignition switch. Either one will turn power ON, and both must be OFF to turn power OFF and shutdown the engine.

A. Build a bypass circuit as shown in the illustration below, using #14 AWG wire.

B. Connect the battery end of the bypass DIRECTLY to the battery posts.

C. Remove Pins A (+ Battery) and B (-Battery) from J2 (Vehicle connector - vehicle side).

D. Insert the other end of the bypass into J2 Pins A and B (as shown below).

E. Connect the wire that was formerly in J2 Pin B into the socket spliced into the bypass.

F. Connect the wire that was formerly in J2 Pin A into the socket that is spliced into the bypass. (This supplies power to the throttle sensor and vehicle speed buffer through the bypass rather than the vehicle wiring). Tape this connection to keep it clean, prevent shorting, and prevent loosening during vehicle operation. Then turn the ignition key OFF. This will isolate the PEEC system from the original vehicle power circuit.

G. Install the temporary switch in the cab.

H. After tests are complete, restore all wiring to original condition.

The engine should perform normally with the bypass installed.

OK: If symptoms disappear with the bypass installed, but come back when it is removed, the problem is in the vehicle wiring supplying power to PEEC. Send the vehicle to the OEM dealer for repair of the vehicle wiring.

NOT OK: If symptoms continue even with the bypass installed, the problem is in PEEC. Continue with the procedure in this manual that best describes the symptom(s).

P-211: Throttle Position Sensor Test

The Throttle Position Sensor (TPS) is used to provide a throttle signal to the ECM. Sensor output is a constant frequency signal whose pulse width varies with throttle position. This output signal is referred to as either "Duty Cycle" or a "Pulse Width Modulated (PWM)" signal and is expressed as a percentage. When correctly adjusted, the remotely mounted TPS will produce a "Duty Cycle" of 15 to 20% at low idle and 80 to 85% at full throttle. The pedal mounted throttle position sensor will produce a "Duty Cycle" signal of 10 to 22% at low idle and 75 to 90% at full throttle. This is then translated by the ECM into a "Throttle Position" of 3 to 100%.

The throttle position sensor may be one of two types. The "Remote-Mounted" (TPS) is about the size of a soft drink can and is connected to the throttle pedal by OEM-supplied linkage. It requires adjustment for proper operation (see procedure P-306). The "Pedal-Mounted" TPS is mounted directly to a specific style of throttle pedal and requires no adjustment, and in fact can not be adjusted. Both sensors provide the same type of signal to the ECM.

Step 1. Check Electrical Connectors And Wiring

Check the vehicle connector (J2/P2) and throttle sensor connector (J12/P12) and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

Step 2. Check Throttle Position Sensor Adjustment

A. If equipped with a "Pedal-Mounted" Throttle Position Sensor, proceed to Step 3.

B. Refer to procedure P-306: Throttle Position Sensor Adjustment to determine if the sensor is correctly adjusted.

The sensor should be able to be correctly adjusted as explained in P-306.

OK: Adjustment is correct. Continue to next step.

NOT OK: The sensor could not be adjusted properly. There is a problem with the sensor circuit. Proceed to Step 4.

Step 3. Check Throttle Position Reading

A. Turn key OFF, then back ON to reset the throttle position reading.

B. Observe the "Throttle Pos" reading on the "Display Status" screen of the ECAP or DDT while pressing and releasing the throttle.

The "Throttle Pos" should read 3% with the throttle pedal released and progressively increase to 100% when the throttle pedal is fully pressed.

OK: The throttle position sensor is currently operating correctly. Stop.

NOT OK: Continue to next step.

Step 4. Check Throttle Sensor Voltage Supply

A. Install a 3-pin 'T' at throttle sensor connector (J12/P12).

B. Measure the voltage between + Battery (Pin A) and ground (Pin B) on the 'T'.

The supply voltage to the sensor should be between 11.5 and 13.5 VDC

OK: Voltage supply OK. Continue to next step.

NOT OK: The throttle position sensor is not being supplied with the correct voltage. Inspect the OEM-supplied wiring and vehicle electrical system for a problem. Stop.

Step 5. Check Throttle Sensor Output Duty Cycle At Throttle Sensor

A. Remove throttle sensor wire (Pin C) from J12. (This disconnects OEM wiring from the sensor).

B. Connect the ECAP or DDT's PWM probe to Pin C of the 'T'.

C. Use the ECAP or DDT to display the Duty Cycle output of the throttle sensor while pressing and releasing the pedal.

The DUTY CYCLE should be between 15 and 20% at the low idle position and increase to between 80 and 85% at the high idle position.

D. Reinsert Wire C in J12.

OK: The throttle sensor is OK. Continue to next step.

NOT OK: The throttle sensor is defective or out of adjustment. Replace or adjust the sensor. Stop.

Step 6. Check Throttle Sensor Duty Cycle At ECM

A. Remove throttle signal (Wire E) from P2. (This disconnects the ECM from the throttle signal).

B. Install a 9-pin 'T' at vehicle connector (J2/P2).

C. Connect the PWM probe to Pin E on the 'T'.

D. Use the ECAP or DDT to display the Duty Cycle of the throttle sensor while pressing and releasing the pedal.

The DUTY CYCLE should be between 15 and 20% at the low idle position and increase to between 80 and 85% at the high idle position.

E. Reinsert Wire E in P2.

OK: A good throttle signal is reaching the ECM. Continue to next step.

NOT OK: The harness is damaged between the ECM and the throttle sensor. Inspect and repair as necessary. Stop.

Step 7. Check ECM

A. Be sure that the wires removed in Steps 4 and 5 have been reinserted.

B. Check to see if Diagnostic Code 32 is ACTIVE.

OK: NOT ACTIVE: The throttle sensor and ECM are currently operating correctly. Stop.

NOT OK: ACTIVE: The ECM is not reading the throttle sensor signal. Be sure that it was determined in Step 6 that a good throttle signal is reaching the ECM. If so, replace the ECM. Stop.

P-212: Diagnostic Lamp Test

The Diagnostic Lamp is used to indicate the existence of a fault, to indicate "driver alert" status of the Idle Shutdown Timer, and may be used to read Diagnostic Codes. While the engine is operating, it will go on for a minimum of 5 seconds any time a fault condition exists. It will remain on as long as the fault is ACTIVE.

On power up and on engine start up, the lamp comes ON for 5 seconds, blinks OFF, comes ON for another 5 seconds, then goes OUT for 5 seconds. After this time, ACTIVE diagnostic codes will be flashed out.

Active faults may also be flashed out at any time by turning the cruise ON/OFF switch to OFF, and holding the SET/RESUME switch in the RESUME position until the lamp begins to flash, then releasing it.

One terminal of the lamp is supplied with battery voltage whenever the key is ON. The other terminal is connected to the ECM at P1/J1 Pin G to turn the lamp on. Pin G will be at battery voltage when the lamp is OFF, and less than 2 volts when the lamp is turned ON.

Step 1. Test Lamp Through ECM

Turn key ON, engine OFF.

The lamp should come ON for 10 seconds, then OUT for 5 seconds, then flash diagnostic codes.

OK: Lamp is working normally. Stop.

NOT OK: Lamp is not working properly. Continue to next step.

Step 2. Bypass The ECM

A. Remove diagnostic lamp wire from P1, Pin G, and ground the wire.

B. Turn key ON, engine OFF. Lamp should come ON and stay ON.

OK: The lamp circuit is OK, but the ECM is not grounding lamp. Replace the ECM. Stop.

NOT OK: Verify that power is reaching lamp socket. If so, replace bulb. Stop.

P-213: Vehicle Speed Signal Test

PEEC uses vehicle speed information for cruise control, to limit engine speed in certain gears, and to limit vehicle speed.

PEEC calculates vehicle speed by converting the vehicle speed signal to miles per hour. The conversion factor is customer programmable and is stored in Pulses Per Mile (PPM).

NOTE: Changing PPM DOES NOT change the actual vehicle speed signal-only the way the ECM converts the signal to mph. (In other words, changing PPM will NOT affect the speedometer).

The vehicle speed circuit consists of the vehicle speed sensor, the vehicle speed buffer, and associated wiring. The sensor is a standard magnetic pickup and is supplied by the truck manufacturer. It senses movement of teeth on the output shaft of the transmission. The buffer (Caterpillar supplied) takes the signal from the sensor, conditions it, and sends it to both the ECM and the vehicle speedometer.

The buffer is supplied with battery voltage through J13/P13 Pin A. Ground is supplied through J13/P13 Pin B. A good ground is very important in order to reduce electrical "noise", which can cause erratic signals.

One of two types of buffers may be used. The 3E0020 buffer is an improved version of the 7T6398, and is a direct pin-for-pin replacement. Either buffer should be grounded at the same point as the ECM to minimize "electrical noise" in the ground circuit.

There are three acceptable options for wiring the vehicle speed circuit:

NOTE: For all three options, the Vehicle Speed Buffer should be grounded to the same ground point as the ECM using a separate, dedicated ground wire. This holds true for either the 7T6398 or the 3E0020 Vehicle Speed Buffer. On 3406B PEEC engines, the ECM ground point is determined by the vehicle manufacture (typically the starter negative post, a cab ground post, or the engine block).

1. Use separate sensors, with the second sensor supplying the signal to the speedometer. This option completely isolates the two circuits and is preferred by Caterpillar. See Illustration 1.

Illustration 1
Recommended vehicle speed circuit wiring when using two separate sensors. For 3E0020 or 7T6398 Vehicle Speed Buffer.

2. Use a single sensor, with the vehicle speed buffer supplying the signal to the speedometer. This option provides good results when properly wired. When using the previous 7T6398 Vehicle Speed Buffer, the circuit should be wired as shown in Illustration 2a. The ground connection for the speedometer should be connected to the ECM ground point, and SHOULD NOT be connected to the cab ground.

Note that this illustration is electrically identical to the schematic in 3406B (PEEC) Diesel Truck Engine Electrical Schematic Form No SENR3486, which is in the complete Service Manual, 3406B (PEEC) Diesel Truck Engine, Form No. SENR3570, but shows the required grounding for the speedometer more clearly.

Illustration 2a
Recommended vehicle speed circuit wiring when using a single sensor with 7T6398 Vehicle Speed Buffer. (See Illustration 2b for 3E0020 Vehicle Speed Buffer).

When using a single sensor with the 3E0020 Vehicle Speed Buffer, the circuit should be wired as shown in Illustration 2b. The grounding requirements for the speedometer are less stringent when using the 3E0020 Vehicle Speed Buffer than when using the 7T6398 Vehicle Speed Buffer.

Illustration 2b
Single sensor wired as recommended for 3E0020 Vehicle Speed Buffer. (See Illustration 2a for 7T6398 Vehicle Speed Buffer).

3. Use a dual winding sensor, with the second winding supplying the signal to the speedometer. This option is not preferred by Caterpillar, but can provide acceptable results if a good quality sensor is used. Dual winding sensors may be used in some new OEM installations which have been specifically reviewed by Caterpillar.

Illustration 3
Recommended vehicle speed circuit wiring when using a dual-winding sensor. For 3E0020 or 7T6398 Vehicle Speed Buffer.

The buffer has outputs to both the ECM and the vehicle speedometer. The output to the ECM is the same on both the 7T6398 buffer and the 3E0020 buffer: a series of 5 volt pulses at J13/P13 Pin D, whose frequency varies directly with the speed of the vehicle.

When a single vehicle speed sensor is used, the speedometer is fed from the buffer.

A. The 7T6398 buffer has one speedometer output of -2.5 to +2.5 volt pulses at J13/P13 Pin C. Pin E is not used on the 7T6398.

B. The 3E0020 buffer has two speedometer outputs, one at Pin C and one at Pin E. Output at each one is a series of -9 volt to +9 volt pulses. The two outputs oppose one another; when Pin C is at +9 volts, Pin E is at -9 volts, and vice versa. Either or both outputs may by used.

Test Procedure:

Step 1. Check Electrical Connectors And Wiring

Check vehicle connectors (J2/P2) and vehicle speed buffer connectors (J13/P13) and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Note which wiring option is used.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

Step 2. Inspect Sensor

Remove the vehicle speed sensor(s) from the transmission and inspect for steel shavings and debris, or damage. Wipe sensor(s) clean. Test sensor according to manufacturer's instructions (sensor is OEM supplied).

OK: Continue to next step.

NOT OK: If sensor is damaged or does not operate properly, replace sensor. Stop.

NOTE: Shavings and debris on the sensor may recur unless the transmission fluid is drained and replaced.

Step 3. Check ECAP/DDT And Speedometer With Truck Parked, Engine Running

Install ECAP or DDT, and run the engine with truck parked, not moving. Try several engine speeds.

The vehicle speedometer and ECAP/DDT should remain at zero mph.

OK: Continue to next step.

NOT OK: Speedometer is giving false readings due to poor grounding. Check that buffer and speedometer grounds are as recommended (see illustrations). Stop.

Step 4. Check Vehicle Speed Correlation

Dyno test or road test vehicle. Compare mph on ECAP/DDT display against speedometer, and against actual vehicle speed as measured on a dyno or by stopwatch.

ECAP/DDT and speedometer should agree with actual speed.

OK: Vehicle speed circuit is working normally. Stop.

NOT OK: * If speedometer is inoperative, intermittent, or inaccurate, repair speedometer circuit or recalibrate speedometer. Stop.

* If ECAP/DDT reading is stable but inaccurate, calculate new scale factor using P-307: Vehicle Speed Calibration, and enter into PEEC system using the ECAP/DDT. Repeat Step 4. Stop.

* If ECAP/DDT reading is absent or intermittent, continue to next step.

Step 5. Check Buffer Supply Voltage

A. Install a 5-pin 'T' on the vehilce speed buffer connector at J13 (vehicle wiring side only).

B. Turn key ON and measure voltage from + battery (Pin A) to ground (Pin B).

Buffer supply voltage should read 11.5 to 13.5 volts DC.

OK: Voltage is correct to the buffer. Continue to next step.

NOT OK: The buffer is not getting correct voltage. Check and repair OEM supplied wiring. Stop.

Step 6. Check Buffer Signal With Truck Parked, Engine OFF (7T6398 only)

NOTE: For 3E0020 go to Step 7.

A. Check Buffer Operation

Disconnect the vehicle speed sensor from the input wires to the vehicle speed buffer. Attach the 'T' to P13 and J13. Remove Wire D at J13 (vehicle side). Measure vehicle speed signal voltage (Pin D to Pin B) (key still ON). Alternately open and short the input wires to the buffer.

The buffer should read 4.5 to 8 volts DC with the input wires open, and less than 1 volt DC with the input wires shorted.

OK: Buffer operation is correct. Continue to next step.

NOT OK: Buffer is not supplying the proper signal to the ECM. Replace buffer. Stop.

B. Check Vehicle Speed Signal Coming To ECM

Reinsert the wire into Pin D of J13, leaving the sensor disconnected from the buffer. Install a 9-pin 'T' at J2 only (vehicle side). Measure the vehicle speed signal voltage (Pin D to Pin B).

Voltage should read 4.5 to 8 volts DC.

OK: The vehicle speed signal is reaching the ECM. Proceed to Step 8.

NOT OK: The vehicle speed signal is not getting to the ECM. Repair fault in harness between J13 and J2. Stop.

Step 7. Check Buffer Signal With Truck Parked, Engine OFF (3E0020 only).

NOTE: For 7T6398 go to Step 6.

A. Check Buffer Operation

1. With key OFF, attach the 'T' to vehicle speed buffer connector P13/J13). Remove wires from Pins C, D, and E of J13 (vehicle side) and note location for reinstallation.

2. Disconnect the buffer input wires from the vehicle speed sensor. Connect the white input wire to Pin A of P13 (+ battery) on the 'T'.

3. Turn key ON. Measure voltages from Pins C, D, and E on the 'T' with respect to Pin B (ground) (white input wire jumpered to P13-A).

The voltages should read as shown below:

Pin D: Less than 1.0 VDC

Pin C: -9.0 ± 1.0 VDC

Pin E: +9.0 ± 1.0 VDC

4. Move the white wire jumper to P13-B (ground), and take the readings again. Voltages should now be opposite:

Pin D: +4.5 to 8 volts DC

Pin C: +9.0 ± 1.0 VDC

Pin E: -9.0 ± 1.0 VDC

5. After taking readings, reinsert wires into J13 C, D, and E.

OK: Buffer is working normally. Continue to next step.

NOT OK: Buffer is not working properly. Replace buffer. Stop.

B. Check Harness Between Buffer And ECM

1. The white wire from the sensor should still be connected to P-13 Pin B.

2. Install a 9-pin 'T' at J2 only (vehicle side). Measure the voltage on the 'T' from J2 Pin D to Pin B.

The voltage should be 4.5 to 8 volts DC.

3. After the test, connect the 'T' to P2 also (ECM side).

OK: The vehicle speed signal is reaching the ECM. Continue to next step.

NOT OK: The vehicle speed signal is not reaching the ECM. Repair fault in harness between J13 and J2. Stop.

Step 8. Dynamic Test Using Engine Speed Signal

A. Install a 9-pin 'T' at transducer module connectors (J5/P5) (both sides).

B. Remove Wire D at P2.

C. Connect a jumper wire from the engine speed signal (Pin A of the 'T' at J5/P5) to Wire D removed from P2. THIS CONNECTS ENGINE SPEED TO THE VEHICLE SPEED INPUT.

D. START THE ENGINE, and read vehicle speed on the ECAP or DDT.

Vehicle speed should read about 10 to 20 mph at an idle speed of 600 rpm.

NOTE: The exact mph is not important in this test - only that the ECM reads the signal.

OK: The ECM is working normally at this time. Stop.

NOT OK: The ECM is not reading the vehicle speed signal. Replace the ECM. Stop.

P-214: Cruise Control And PTO Switches Test

The PEEC cruise control operates similar to automotive cruise controls. PTO mode operates similar to cruise, only it governs engine speed with the vehicle stationary. Four switch inputs to PEEC affect cruise or PTO:

1. CRUISE ON/OFF

This switch must be ON for cruise or PTO to be activated. The signal goes to J2/P2 (Vehicle connector), Pin F.

2. SET/ACCEL

With the ON/OFF switch ON, momentarily pressing this switch will activate cruise, and will tell the cruise or PTO to try to maintain the current speed. Holding this switch ON will cause cruise or PTO to slowly accelerate this setpoint. The signal goes to J2/P2 (Vehicle connector), Pin J.

3. RESUME/DECEL

With the ON/OFF switch ON, momentarily pressing this switch will also activate cruise, and will tell the cruise or PTO to resume with the setpoint used when cruise was last disabled. Holding this switch ON will cause cruise or PTO to slowly decelerate this setpoint. The signal goes to J2/P2 (Vehicle connector), Pin H.

4. CLUTCH/BRAKE

Depressing either the clutch or the brake pedal will cause cruise or PTO to deactivate. The signal goes to J2/P2 (Vehicle connector), Pin G.

NOTE: All these switches are typically in the truck cab, and are supplied by the OEM. To troubleshoot the ON/OFF, SET, or RESUME switches, use this procedure. To troubleshoot the CLUTCH or BRAKE switches, use P-215: Service Brake And Clutch Switch Test.

Voltage at each of the switch inputs to the ECM should be 5.0 ± 0.5 volts with the switch open (or OFF), and less than 0.5 volts with the switch closed (or ON).

Step 1. Check Switch Status On ECAP Or DDT

A. Install ECAP or DDT and turn key ON.

B. Operate CRUISE ON/OFF switch while observing status of "Cruise/PTO Sw".

C. Operate SET/ACCEL switch while observing status of "Set Sw".

D. Operate RESUME/DECEL switch while observing status of "Resume Sw".

The status of each should read "ON" with the switch On, and "OFF" with the switch OFF.

OK: The switches are operating normally. Stop.

NOT OK: The ECM is not seeing the switch status change. Continue with next step.

Step 2. Check Switch Resistance At Vehicle Connector

A. Connect a 9-pin 'T' to J2 (vehicle connector) (vehicle side only).

B. Using a ohmmeter, Measure the resistance from each switch output terminal (listed below) to J2 Pin B (- Battery). Operate each switch and measure the resistance with switch closed and with switch open.

The resistances should be:

CRUISE ON

J2 Pin F to J2 Pin B (-Battery) < 10 ohms

CRUISE OFF

J2 Pin F to J2 Pin B (-Battery) > 10 K ohms

SET/ACCEL ON

J2 Pin J to J2 Pin B (-Battery) < 10 ohms

SET/ACCEL OFF

J2 Pin J to J2 Pin B (-Battery) > 10 K ohms

RESUME/DECEL ON

J2 Pin H to J2 Pin B (-Battery) < 10 ohms

RESUME/DECEL OFF

J2 Pin H to J2 Pin B (-Battery) > 10 K ohms

OK: Vehicle wiring checks OK. If Step 1 found that the ECM is not seeing the switch status change, then the ECM is getting the proper signals, but is not reading them correctly. Verify that the ECM is receiving proper battery voltage. If so, replace the ECM. Stop.

NOT OK: There is a problem in the vehicle wiring. Repair as needed, using the OEM wiring schematics, or refer to the OEM dealer. Stop.

P-215: Service Brake And Clutch Switch Test

The BRAKE and CLUTCH switches are used in cruise control or PTO mode to discontinue cruise or PTO operation. The switches may also be used to override the Idle Shutdown Timer.

The brake and clutch switches are normally closed and are wired in series to ground. Depressing either the clutch or brake opens the circuit. The signal goes to the ECM through P2/J2 Pin G. Voltage at Pin G should be 5.0 ± 0.5 volts with either switch open, and less than 0.5 volts with both switches closed.

Vehicle wiring for an engine brake may affect operation of this circuit. For example, the switch to turn the engine brake on may open this circuit (similar to turning the service brake on). Refer to the service manual for the vehicle to determine how the engine brake is wired.

Both switches are OEM supplied. The brake switch is typically a pressure switch. The clutch switch is typically a limit switch mounted near the clutch pedal. The clutch switch is usually adjustable.

Step 1. Check Brake Switch Status With ECAP Or DDT

A. Install ECAP or DDT and turn key ON.

B. Operate the service BRAKE pedal while observing status of the "Clutch/Brake Sw".

C. Operate the CLUTCH pedal while observing status of the "Clutch/Brake Sw".

Switch status should be "OFF" with both pedals released and "ON" with the either pedal depressed. The clutch pedal should feel resistance before the clutch switch engages.

OK: The clutch and brake switches are operating normally. Stop.

NOT OK: Check adjustment of the clutch switch, then repeat this step. If the ECM is still not seeing the switch status change, continue to next step.

Step 2. Check Switch Resistance At Vehicle Connector

A. Connect a 9-pin 'T' to J2 (vehicle connector) (vehicle side only).

B. Using an ohmmeter, Measure the resistance from each switch output terminal (listed below) to J2 Pin G (- Battery). Operate each switch and measure the resistance with switch ON and OFF.

The resistances should be:

Brake and Clutch OFF (both pedals released)

J2 Pin G to J2 Pin B (-Battery) < 10 ohms

Brake ON (pedal depressed)

J2 Pin G to J2 Pin B (-Battery) > 10 K ohms

Clutch ON (pedal depressed)

J2 Pin G to J2 Pin B (-Battery) > 10 K ohms

OK: Vehicle wiring checks OK. If Step 1 found that the ECM is not seeing the switch status change, then the ECM is getting the proper signals, but is not reading them correctly. Verify that the ECM is receiving proper battery voltage. If so, replace the ECM. Stop.

NOT OK: There is a problem in the vehicle wiring. Repair as needed, using the OEM wiring schematics, or refer to the OEM dealer. Stop.

P-216: Parking Brake Switch Test

The PARKING BRAKE switch is used only to enable the Idle Shutdown Timer. The idle shutdown timer will only be activated when the parking brake is ON.

The parking brake switch is supplied by the OEM. It should be normally closed (with brake applied, and no air pressure to the parking brake) and connected to ground. Releasing the brake should open the circuit. The idle shutdown timer will NOT operate unless the switch is installed to connect the parking brake input to ground.

The signal goes to the ECM through P1/J1 Pin D. Voltage at Pin D should be 5.0 ± 0.5 volts with the switch open (parking brake released), and less than 0.5 volts with the switch closed (parking brake applied).

Step 1. Check Switch Status With ECAP Or DDT

A. Install ECAP or DDT and turn key ON.

B. Operate the PARK BRAKE while observing status of the "Park Brake Sw".

Switch status should be "OFF" with the brake released and "ON" with the brake applied.

OK: The park brake switch is operating normally. Stop.

NOT OK: The ECM is not seeing the switch status change. Continue to next step.

Step 2. Check Switch Resistance At Vehicle Connector

A. Connect a 9-pin 'T' to P1 (diagnostic connector) (harness side only).

B. Using an ohmmeter, Measure the resistance from the switch output terminal (listed below) to J2 Pin B (- Battery). Operate the parking brake switch and measure the resistance with switch ON and OFF.

The resistances should be as shown below

Parking Brake ON

Pin D (P1) to [(-Battery) Pin B (P2)] < 10 ohms

Parking Brake OFF

Pin D (P1) to [(-Battery) Pin B (P2)] > 10 ohms

OK: The switch harness checks OK. If Step 1 found that the ECM is not seeing the switch status change, then the ECM is getting the proper signals, but is not reading them correctly. Verify that the ECM is receiving proper battery voltage. If so, replace the ECM. Stop.

NOT OK: There is a problem in the vehicle wiring. Repair as needed, using the OEM wiring schematics, or refer to the OEM dealer. Stop.

P-220: ECM/Personality Module Test

The Electronic Control Module (ECM) is the computer which controls a PEEC engine. The Personality Module is the software which controls how the computer behaves. The two must be used together -neither can do anything by itself.

The Personality Module consists of:

* All of the software, or instructions, for the ECM to do its job. Because of this, updating the Personality Module to a new version may cause the engine to behave in a different manner. The section on Summary Of PEEC Personality Module Changes in this manual describes the changes that have been made to the software.* Performance Maps, which define fuel rate, timing, etc. for various operating conditions to achieve optimum performance while meeting emission requirements. These are programmed at the factory only.* Logged Diagnostics (in modules produced since April 1989). PEEC may log certain diagnostic codes into this memory so that a permanent record of the diagnostic is retained. Refer to the section Troubleshooting Diagnostic Codes, for further information on logged codes.

The ECM consists of:

* A microprocessor, to perform the computing necessary to perform the ECM's functions (governing, controlling timing, generating diagnostic codes, communicating with service tools, etc.). The microprocessor gets its instructions from the software in the Personality Module.* Programmable Parameters stored in permanent memory (both Customer Specified and System Configuration Parameters). Refer to the section Programming PEEC Parameters for details on what these parameters do.* Input Circuits, to filter electrical noise from sensor signals and to protect sensitive internal circuits from potentially damaging voltage spikes.* Output Circuits, to provide the high currents necessary to turn on lamps or solenoids as the microprocessor chooses.* Power circuits, to provide clean stable electrical power to internal circuits and external sensors.

Step 1. Inspect Electrical Connectors And Wiring

Inspect all wiring and connectors coming in and out of the ECM for damage, corrosion, or incorrect attachment. Repair any problems.

Step 2. Inspect The Personality Module Connector And Gasket.

A. Remove the Personality Module. Note gasket location and orientation while removing the module.

B. Inspect the connector on the Personality Module and on the ECM for corrosion or damage.

C. Inspect the gasket to be sure that it was properly aligned when installed. Also check that the cork shipping gasket was removed before previous assembly.

D. Re-install the module, or replace or repair as needed.

Step 3. Check Communication With ECAP or DDT

A. Install ECAP or DDT.

B. Read Customer Specified Parameters (see instructions for the service tool for details).

C. Read LOGGED Codes (if equipped with Personality Module built since May 1989).

D. Start the engine.

The ECAP/DDT should be able to read correct parameters, the hour meter for logged codes should represent approximate operating time for the Personality Module, and the engine should start and run normally.

OK: The Personality Module is OK. The microprocessor in the ECM is able to properly function and read the memory in the ECM and Personality Module. The remainder of the ECM (input circuits, output circuits, and sensor supply and reference voltage circuits) are to be tested individually. If operational problems persist, refer to the procedure in this manual best describing the symptoms. Stop.

NOT OK: * If the ECAP/DDT will not communicate with the ECM, refer to P-120: ECAP/DDT will Not Communicate With PEEC.

* If the Customer Specified Parameters are not as expected, reprogram the parameters. Completely scrambled parameters could mean the ECM is defective.* If the hour meter for logged codes is scrambled or stuck at zero, or the logged codes are completely scrambled, the Personality Module may be defective. Excessive voltage spikes in the vehicle electrical system may also cause scrambled logged codes or hour meter reading. Locate the source of the electrical spike (engine brake relays, cooling fan solenoids, and air conditioner compressors are common causes) and suppress the spike with a diode across the relay or solenoid coil.* If the engine will not start, refer to P-102: Engine Cranks But Will Not Start.

P-221: Sensor Supply Voltage Test

The PEEC ECM converts the battery voltage into 5V and 8V sensor supply voltages. These supply voltages are used to supply power and reference voltages to the following sensors: rack, timing, engine speed, boost pressure (in transducer module), and oil pressure (in transducer module). In addition to using the sensor supply voltages for the boost and oil sensors, the transducer module has internal connections which pass the sensor supply voltages on to the rack sensor and engine speed sensor.

NOTE: A short anywhere on the 8 volt sensor supply circuit will cause loss of the engine speed signal, which will result in an engine shutdown.

Step 1. Check Electrical Connectors And Wiring

Check ECM/sensors (J3/P3) and transducer module (J5/P5), timing position sensor (J7/P7), rack position sensor (J8/P8), and engine speed sensor (J9/P9) connectors and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

Step 2. Check Supply Voltages At ECM

A. Connect a 9-pin 'T' at J3 ONLY (sensors connector at ECM), leaving harness disconnected from 'T'.

B. Turn key ON, engine OFF.

C. Measure the 8V sensor supply voltage (Pin H to Pin B) and the 5V reference voltage (Pin C to Pin B).

The 8V sensor supply voltage should be 8.0 ± 0.4 VDC and the 5V reference voltage should be 5 ± 0.25 VDC.

OK: The ECM is supplying the correct voltages. Continue to next step.

NOT OK: The ECM is NOT supplying the correct voltages. Refer to P-210: Electrical Power Supply To PEEC test to verify that the ECM is getting battery voltage. If it is, replace the ECM. Stop.

Step 3. Check For Components Shorting Supply Voltages

A. Connect the 9-pin 'T' to both J3 AND P3 (sensors connector at ECM)

B. Turn key ON, engine OFF.

C. Measure the 8V sensor supply voltage (Pin H to Pin B) and the 5V reference voltage (Pin C to Pin B).

The 8V sensor supply voltage should be 8.0 ± 0.4 VDC and the 5V reference voltage should be 5 ± 0.25 VDC.

OK: There are no components shorting the supply or reference voltages. Continue to next Step 4.

NOT OK: A PEEC component is shorting either the 8V sensor supply voltage or the 5V reference voltage. Disconnect the timing position sensor, transducer module, rack position sensor, engine speed sensor and engine harness one at a time while monitoring the 8V sensor supply and 5V reference voltages to determine which component is causing the short, and replace or repair that component.

If one of the voltages drops no matter which component is connected, the voltage supplies in the ECM may not be able to supply enough current. If so, replace the ECM. Stop.

Step 4. Check Supply Voltages To Transducer Module

A. Connect a 9-pin 'T' at transducer module connector (J5/P5).

B. Measure the 8V sensor supply voltage (Pin H to Pin B) and the 5V reference voltage (Pin C to Pin B).

The 8V sensor supply voltage should be 8.0 ± 0.4 VDC and the 5V reference voltage should be 5 ± 0.25 VDC.

OK: Supply voltages are OK to transducer. Continue to next step.

NOT OK: Inspect connectors and wiring between ECM and transducer for damage or a broken connection. Repair any problems. Stop.

Step 5. Check Supply Voltages To Rack Position Sensor

A. Connect a 5-pin 'T' at rack sensor connector (J8/P8).

C. Measure the 8V sensor supply voltage (Pin A) and 5V reference voltage (Pin C) with respect to ground (Pin B).

The 8V sensor supply voltage (Pin A) should be 8.0 ± 0.4 VDC and the 5V reference voltage (Pin C) should be 5 ± 0.25 VDC.

OK: Supply voltages are OK to the rack sensor. Continue to next step.

NOT OK: Supply voltages are making it to the transducer, but not through it. Replace the transducer. Stop.

Step 6. Check Supply Voltages To Engine Speed Sensor

A. Connect a 3-pin 'T' at engine speed sensor connector (J9/P9).

B. Measure the 8V sensor supply voltage (Pin A to Pin B)

The 8V sensor supply voltage should be 8.0 ± 0.4 VDC

OK: Supply voltages are OK to the engine speed sensor. Continue to next step.

NOT OK: Supply voltages are making it to the transducer, but not through it. Replace the transducer module. Stop.

Step 7. Check Supply Voltages To Timing Position Sensor

A. Connect a 5-pin 'T' at timing sensor connector J7/P7).

B. Measure the 8V sensor supply voltage (Pin A to Pin B) and the 5V reference voltage (Pin C to Pin B).

The 8V sensor supply voltage should be 8.0 ± 0.4 VDC and the 5V reference voltage should be 5 ± 0.25 VDC.

OK: Supply voltages are OK to all PEEC components. Stop.

NOT OK: Inspect connectors and wiring between ECM and timing sensor for damage or a broken connection. Repair any problems. Stop.

P-222: Engine Speed Signal Test

The PEEC engine speed sensor determines engine speed by magnetically detecting the teeth on the fuel pump camshaft retainer. PEEC will not try to start the engine (either energize the shutoff solenoid or move the BTM until it senses an engine speed signal). Engine speed is determined by the FREQUENCY, not the voltage, of the engine speed sensor output. The output frequency should be between 0 and 460 Hz. The sensor is supplied with 8V from the ECM through the transducer module.

Step 1. Inspect Electrical Connectors And Wiring

A. Check ECM/sensors (J3/P3) and transducer module (J5/P5) connectors and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

B. Remove the rear cover from the governor.

C. Inspect engine speed sensor (J9/P9) and wiring for abrasion, damage, or incorrect attachment. Repair any damage.

D. Remove engine speed sensor, and check sensing end of sensor for damage. Replace sensor if damaged.

E. Reinstall the components removed in the previous steps.

Step 2. Engine Speed Signal Operational Test

Start the engine.

The engine should start and run smoothly.

OK: The engine speed signal is currently operating correctly. Stop.

NOT OK: * Will Not Start: Refer to procedure P-102: Engine Cranks But Will Not Start. If the problem is still not found, continue to Step 3.

* Erratic RPM: Refer to procedure P-104: Erratic Or Unstable Engine RPM. If the problem is still not found, continue to Step 3.

Step 3. Check Engine RPM Reading On ECAP/DDT

NOTE: Since vehicle battery voltage may dip momentarily below operating minimum for the ECM and ECAP during cranking, electrical power may need to be supplied from an external isolated source (such as a battery cart) for this step. Do not connect the OEM wiring to J2 Pins A and B as shown in the Bypass Schematic shown in P-210.

Crank the engine while observing the "Engine RPM" reading on the "Display Status" screen of the ECAP or DDT.

"Engine RPM" while cranking should show a steady reading between 100 and 500 rpm.

OK: The engine speed sensor is currently working correctly. Stop.

NOT OK: The ECM is not reading an engine speed signal. Continue to next step.

Step 4. Check Engine Speed Signal At ECM

A. Connect a 9-pin 'T' at the ECM/sensors connector (J3/P3).

B. Connect the PWM probe at Pin A (engine speed) of the 'T'.

C. Remove engine speed signal wire from ECM (Pin A of J3).

D. Crank the engine and observe the frequency of the engine speed sensor signal. Refer to the instructions included with the PWM probe (use the "Utility" function from the Main Menu, then select "PWM Sensor").

E. Reinsert Wire A in J3.

The Frequency displayed on the ECAP or DDT should be between 10 and 50 Hz and steady while cranking.

OK: The engine speed signal is reaching the ECM. If Step 3 showed that the ECM was not reading the signal, the ECM is faulty. Replace the ECM. Stop.

NOT OK: The engine speed signal is not reaching the ECM. Continue to next step.

Step 5. Check Engine Speed Signal Through Transducer Module

A. Connect a 9-pin 'T' at the transducer module connector (J5/P5).

B. Remove engine speed signal wire from the engine harness (Pin A of J5).

C. Connect the PWM probe to Pin A (engine speed) of the 'T'.

D. Crank the engine and observe the frequency of the engine speed sensor output. Refer to the instructions included with the PWM probe (use the utility function from the main menu, then select "PWM sensor").

E. Reinsert Wire A in J5.

The frequency displayed on the ECAP or DDT should be between 10 and 50 Hz and steady while cranking.

OK: The engine speed sensor is working, and its signal is getting through the transducer module but not reaching the ECM. Check connections and the wiring between the ECM and transducer for damage, corrosion, or incorrect attachment. Repair as needed. Stop.

NOT OK: Engine speed signal is not reaching the transducer module connector. Continue to the next step.

Step 6. Check Sensor Supply Voltage At Engine Speed Sensor

A. Connect a 3-pin 'T' at (engine speed sensor connector J9/P9).

B. Measure the 8V sensor supply voltage (Pin A to Pin B of the 'T').

The voltage should be 8 ± 0.4 VDC.

OK: The engine speed sensor is receiving proper voltage. Continue to next step.

NOT OK: The engine speed sensor is not getting proper supply voltage. Refer to P-221: Sensor Supply Voltage Test. Stop.

Step 7. Check Engine Speed Sensor Operation

A. Connect the PWM probe at engine speed signal (Pin C) of the 'T'.

B. Remove engine speed signal wire from the transducer (Pin C of P9).

C. Crank the engine and observe the frequency of the engine speed signal. Refer to the instructions included with the PWM probe (use the "Utility" function from the main menu, then select "PWM Sensor").

E. Reinsert Wire C in P9.

The frequency displayed on the ECAP or DDT should be between 10 and 50 Hz and steady while cranking.

OK: The engine speed sensor is OK, but the signal is not getting through the transducer module. Check for damaged wires or connectors coming from the transducer. If no damage is found, replace the transducer module. Stop.

NOT OK: The engine speed sensor is not generating a proper signal. Replace the sensor. Stop.

P-223: Shutoff Solenoid Test

Although the Rack Solenoid (BTM) is capable of shutting the engine down, the shutoff solenoid provides a redundant means for PEEC to shut down the engine. When the solenoid receives a voltage, the solenoid's plunger is pulled in to allow the engine to run. When the solenoid does not receive voltage, the plunger will release and the engine will not run.

The shutoff solenoid should receive 6 to 12 VDC from the OEM crank relay during cranking, through the "crank" input on the ECM [Pin C of vehicle connector (J2/P2)], but no voltage from the crank relay while running. While the engine is running, the ECM supplies 1.5 to 2.5 VDC to the shutoff solenoid.

Step 1. Check Electrical Connectors And Wiring

Check shutoff solenoid connector (J11/P11) and ECM/solenoids connector (J4/P4) and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

Step 2. Verify Proper Wiring Of The Crank Line

A. Connect a 9-pin 'T' to vehicle connector (P2/J2).

B. Rotate the manual shutoff lever counterclockwise (CCW) to prevent the engine from starting.

C. Measure the voltage between the crank line (Pin C) and ground (Pin B) of the 'T' while the engine is stopped (key ON) and then while cranking.

The voltage should be less than 1 VDC with the engine stopped and greater than 6 VDC while cranking.

BOTH Voltages OK: The crank relay is OK. Continue to next step.

EITHER Voltage NOT OK: Repair the OEM crank relay or its wiring, then continue to the next step.

Step 3. Override Shutoff Solenoid Operation

A. Rotate the manual shutoff lever in the clockwise direction (CW) to override the shutoff solenoid.

B. Start the engine.

C. Release the manual shutoff lever.

The engine should have started, and should continue to run after the manual shutoff lever is released.

OK: The shutoff solenoid appears to be working. Continue to next step.

NOT OK:*If the engine will still not start, the problem is NOT with the shutoff solenoid. Refer to P-102: Engine Cranks But Will Not Start. Stop.

*If the engine starts but dies when manual lever is released, the shutoff solenoid is not working. Proceed to Step 5.

Step 4. Verify That Shutoff Solenoid Can Shutdown Engine

A. Start engine.

B. Disconnect shutoff solenoid connector (J11/P11).

The engine should shutdown when the shutoff solenoid is disconnected.

OK: Shutoff solenoid is able to shutdown engine. Continue to next step.

NOT OK: Shutoff solenoid IS NOT able to shutdown engine. Check for sticking solenoid plunger or linkage. Then repeat this step.

Step 5. Measure Operating Voltage At Shutoff Solenoid

A. Connect a 3-pin 'T' at shutoff solenoid connector (J11/P11).

B. Rotate the manual shutoff lever in a clockwise (CW) direction to override the shutoff solenoid.

C. Start the engine and allow it to warm up to operating temperature.

D. Measure the voltage between shutoff signal (Pin A) and ground (Pin B) of the 'T' during cranking, and while the engine is running.

The voltage should jump to over 4 volts during cranking and then stabilize at between 1.5 and 2.5 volts DC.

OK: The shutoff solenoid is currently operating correctly. Stop.

NOT OK: The shutoff solenoid is not getting proper voltage.

* If voltage is less than 1.5 VDC, replace the shutoff solenoid and retest. If voltage is still too low, proceed to Step 6.

* If voltage is greater than 2.5 VDC, verify proper wiring of the crank line (refer to Step 2). If crank line is OK, proceed to Step 6.

Step 6. Check Resistance Of Solenoid Coil

A. Disconnect shutoff solenoid.

B. Measure the resistance across the solenoid coil (Pin A to Pin B of J11).

The resistance should be between 1 and 2 ohms.

OK: The solenoid coil resistance is OK. Continue to next step.

NOT OK: The shutoff solenoid is defective. Replace the solenoid. Then repeat Step 5.

Step 7. Check For Solenoid Short To Case

A. Clean or remove paint from a portion of the solenoid case so that a solid electrical connection can be made to the case.

B. Set the multimeter to measure resistance on the 2 Meg-ohm scale (2M).

C. Measure the resistance between the solenoid coil (Pin A of J11) and the solenoid case.

The resistance should be too high to measure. This is usually indicated by "OL" being displayed on the multimeter.

OK: The solenoid is OK. Continue to next step.

NOT OK: The solenoid is shorted to the case. Replace the solenoid. Then repeat Step 5.

Step 8. Check Solenoid Voltage From ECM

A. Reconnect shutoff solenoid connector (J11 to P11).

B. Install a 5-pin 'T' at ECM/solenoids connector (J4/P4).

C. Start the engine.

D. Measure the shutoff solenoid voltage (Pin E to Pin B (ground) of the 'T') while the engine is running.

The voltage should be between 1.5 and 2.5 VDC with the engine running.

OK: The ECM is supplying the correct voltages. Inspect the wiring harness between the ECM and the shutoff solenoid for damage or a broken connection. Repair as needed. Stop.

NOT OK: The ECM is not supplying the correct voltages to the solenoid. Replace the ECM. Stop.

P-224: Boost Pressure Sensor Test

The PEEC system monitors boost pressure with a sensor located in the transducer module. The boost sensor is supplied with electrical power by the 8 volt sensor supply and 5 volt reference voltages from the ECM. The sensor can only by replaced by replacing the transducer module.

The boost sensor is used to limit smoke emissions during acceleration. PEEC limits the amount of fuel injected until certain boost pressures are reached. It does this by converting boost pressure to "FRC RAck" (as shown on the ECAP status display). The FRC Rack (Fuel Ratio Control) is then a limit on rack position based on boost pressure.

PEEC does NOT currently use an atmospheric pressure sensor, even though some transducer modules are equipped with one. However, the inlet air hose from the air cleaner to the transducer module MUST still be installed. It serves as a vent for the transducer module and is required for proper operation of the boost pressure sensor.

Step 1. Check Electrical Connectors And Wiring

Check transducer module connector (J5/P5) and ECM/sensors connector (J3/P3) and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

Step 2. Visual Inspection

A. Verify that the boost and inlet air hoses are correctly installed (boost hose to top of intake manifold, and inlet air hose to clean air side of air filter).

B. Inspect the hoses for cracks, leaks or other damage. Make any necessary repairs.

Step 3. Calibrate Boost Sensor

Refer to procedure P-305: Boost Pressure Sensor Calibration to calibrate the boost sensor. The engine should be warmed up to operating temperature before calibration is performed.

The ECAP or DDT should indicate that the boost sensor was calibrated.

OK: Continue to next step.

NOT OK: Boost sensor voltages are not within specified range. Proceed to Step 6.

Step 4. Boost Sensor Pressure Test

A. Disconnect the boost pressure and inlet air pressure lines from the transducer module.

B. Connect the FT1906 Fuel Ratio Control Pressure Kit to the boost pressure port on the transducer module.

C. Observe the boost pressure display on the ECAP or DDT's Display Status Screen.

D. Close the pressure cock valve on the pressure test kit and apply 100 kPa (14.5 psi) to the boost pressure port.

E. Compare the readings on the ECAP or DDT with pressure test kit.

The ECAP or DDT should show 0 kPa when no pressure is applied and agree within ± 7 kPa (1.0 psi) of the test kit.

OK: Boost sensor appears to operate normally. Continue to next step.

NOT OK: The ECM is not receiving a proper boost sensor signal. Reconnect boost and inlet air hoses. Proceed to Step 6.

Step 5. Leakage Test

A. Close the pressure cock valve on the pressure test kit and again apply 100 kPa (14.5 psi) to the boost pressure port.

B. Observe the boost pressure reading on the ECAP or DDT for 30 seconds before releasing the pressure.

C. Disconnect the pressure kit and reconnect the boost and inlet air hoses.

The leakage rate should not exceed 20 kPa (3 psi) in 30 seconds.

OK: The Boost pressure sensor is currently operating correctly. Stop.

NOT OK: Check for leaks in the hose or the test kit. If none are found, there is an internal leak in the transducer module. Replace the transducer module and calibrate the new boost sensor. Stop.

Step 6. Check Sensor Supply Voltage

A. Connect a 9-pin 'T' at transducer module connector (J5/P5).

B. Measure the 8V sensor supply voltage (Pin H to Pin B), and the 5V reference voltage (Pin C to Pin B).

The 8V sensor supply voltage should be 8.0 ± 0.4 VDC and the 5V reference voltage should be 5 ± 0.25 VDC.

OK: Sensor is receiving proper supply voltage. Continue to next step.

NOT OK: There is a problem with the supply voltage. Refer to procedure P-221: Sensor Supply Voltage Test. Stop.

Step 7. Check Boost Pressure Signal At Transducer Module

A. Remove boost signal wire from the wiring harness connector (Wire E of J5) to isolate the boost sensor from the wiring harness.

B. Measure the boost sensor signal voltage at Pin E of the 'T'.

C. Reinsert Wire E in J5.

The boost sensor signal voltage should be between 0.7 and 1.2 VDC.

OK: The boost sensor is working properly. Continue to next step.

NOT OK: The boost pressure sensor is defective. Replace the sensor. Stop.

Step 8. Check Boost Pressure Signal At ECM

A. Connect a 9-pin 'T' at ECM/sensors connector (J3/P3).

B. Remove boost pressure signal wire from the ECM connector (Wire E of J3) to isolate the ECM from the boost signal.

C. Measure the voltage between the boost pressure signal (Pin E) and ground (Pin B) of J3.

D. Reinsert Wire E in J3.

The boost pressure signal voltage should be between 0.7 and 1.2 VDC.

OK: The boost signal is good at the ECM. Continue to next step.

NOT OK: There is a problem with the wiring harness between the transducer module and the ECM. Inspect the wiring and connectors for damage or a broken connection. Repair as necessary. Stop.

Step 9. Check ECM

The previous step verified that a good boost signal is reaching the ECM.

The boost sensor should calibrate, display an accurate reading, and Diagnostic Code 25 should NOT be ACTIVE.

OK: The boost sensor is currently working correctly. Stop.

NOT OK: Be sure the wires removed previously have been replaced. If so, the ECM is not reading the boost signal. Replace the ECM.

P-225: Oil Pressure Sensor Test

The PEEC system monitors oil pressure with a sensor located in the transducer module. The oil pressure sensor is supplied with electrical power by the 8 volt sensor supply and 5 volt reference voltages from the ECM.

The oil pressure sensor can measure oil pressure from 0 kPa (0 psi) to 312 kPa (45 psi). Any pressure greater than 312 kPa is displayed as 312 kPa. The oil pressure measured by PEEC is about 10 kPa less than the gallery oil pressure.

After the engine has been running for ten seconds, PEEC will monitor oil pressure to ensure that it stays above certain limits. When it drops below the limits, PEEC will limit engine speed to 1,350 rpm, and generate Code 46 (Low Oil Pressure Warning). These limits are in the procedure for Diagnostic Code 46.

Note that PEEC uses the oil pressure only as an engine protection function. Lack of oil pressure does not prevent PEEC from starting the engine. PEEC will still try to start the engine even if oil pressure is low.

It is NOT NORMAL to get Diagnostic Code 24 with the key ON, engine OFF, or to read 310 kPa (45 psi) with the key ON, engine OFF.

Step 1. Check Electrical Connectors And Wiring

Check transducer module connector (J5/P5) and ECM/solenoids connector (J3/P3) and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

Step 2. Check Oil Level

Check engine oil level and check that correct dipstick is installed. Also look for fuel dilution of oil and oil leaks. Correct any problems.

Step 3. Check ECAP Or DDT Display With Engine OFF

A. Turn key ON, engine OFF.

B. Observe the "Oil Press" reading on the ECAP or DDT's "Display Status" screen.

The ECAP should display 0 kPa (0 psi) for oil pressure when the engine is not running. (A Diagnostic Code 46 may be shown with the engine not running. Only be concerned about a Diagnostic Code 46 when the engine is running.)

OK: The sensor appears to be operating normally. Continue to next step.

NOT OK: The sensor is reading pressure where none exists. Proceed to Step 6.

Step 4. Check Pressure With Engine Running

A. Start the engine.

B. Observe ECAP/DDT Status Screen and monitor "Oil Press".

Pressure should exceed 35 kPa (5 psi) within five seconds and fall within the "Acceptable Region" given on the Engine Oil Pressure Graph.

OK: The sensor appears to be operating normally. Stop.

NOT OK: Turn the engine OFF. Continue to Step 5.

Engine Oil Pressure Graph

Step 5. Check Actual Oil Pressure

A. Install the 1U5470 Engine Pressure Group to measure engine oil pressure (fitting at the camshaft bearing at the left rear corner of the engine block).

B. Start the engine and run at low idle. If after five seconds the oil pressure does not exceed 35 kPa (5 psi), shut off the engine.

C. Push the throttle to the high idle position.

D. Check for oil leakage. Repair any leaks.

E. Compare the engine oil pressure to the acceptable range of oil pressure on the ENGINE OIL PRESSURE GRAPH.

The engine oil pressure reading on the Engine Pressure Group should exceed 35 kPa (5 psi) after five seconds and fall within the "Acceptable Region" given on the ENGINE OIL PRESSURE GRAPH.

OK: Actual oil pressure is OK. Continue to next step.

NOT OK: There is a problem with the engine oil pressure. Refer to 3406B PEEC Diesel Truck Engine, Systems Operation Testing and Adjusting, Form No. SENR3485.

Step 6. Compare ECAP Display With 1U5470 Reading

A. Start engine and wait until oil pressure builds to at least 35 kPa (5 psi).

B. Vary the engine speed. Compare the oil pressure reading on the "Display Status" screen of the ECAP or DDT with the reading given by the 1U5470.

NOTE: The maximum oil pressure measured by PEEC is 312 kPa (45 psi). Engine oil pressure greater than 312 kPa is shown as 312 kPa. PEEC will measure about 10 kPa lower pressures than the 1U5470 pressure group due to pressure losses between the main oil pressure gallery and the fuel injection pump.

The oil pressure readings on the ECAP should be about 10 kPa less than the readings on the 1U5470.

OK: The oil pressure sensor is currently operating correctly. Stop.

NOT OK: The sensor is not reading oil pressure correctly. Continue to the next step.

Step 7. Check Supply Voltage To Transducer Module

A. Turn key ON, engine OFF.

B. Connect a 9-pin 'T' at J5/P5.

C. Measure the 8V sensor supply voltage (Pin H to Pin B) and the 5V reference voltage (Pin C to Pin B).

The 8V sensor supply voltage should be 8.0 ± 0.4 VDC and the 5V reference voltage should be 5.0 ± 0.25 VDC.

OK: Voltage supply is OK. Continue to next step.

NOT OK: There is a problem with the voltage supply to the transducer module. Refer to P-221: Sensor Supply Voltage Test. Stop.

Step 8. Check Sensor Output

A. Remove oil pressure signal wire from the harness connector (Wire G of J5) to isolate signal.

B. Measure the oil pressure signal (Pin G to Pin B) of the 'T' with the engine not running (key ON), and with the engine running at 600 and at 1350 rpm.

C. Compare the measured voltages with the minimum sensor outputs given in Table A.

D. Reinsert Wire G in J5.

The oil pressure signal voltages should all be greater than the minimum values given in Table A.

OK: The oil pressure sensor is OK. Continue to the next step.

NOT OK: The oil pressure sensor is defective. Replace the transducer module and recalibrate the Boost Sensor. Stop.

Step 9. Check Oil Pressure Signal At ECM

A. Remove oil pressure signal wire from the ECM connector (Wire G of J3).

B. Connect a 9-pin 'T' at ECM/sensors connector (J3/P3).

C. Measure the oil pressure signal voltage (Pin G to Pin B) of the 'T' with the engine not running (key ON), at 600 rpm, and at 1350 rpm.

D. Compare the measured voltages with the minimum sensor outputs given in Table A.

E. Reinsert Wire G in J3.

The oil pressure signal voltages should all be greater than the minimum values given in Table A.

OK: Oil pressure signal is reaching the ECM. Continue to next step.

NOT OK: There is a problem with the harness between the transducer module and the ECM. Inspect the wiring harness and connectors for damage or a broken connection. Stop.

Step 10. Check ECM

A. Check that the wires removed in previous steps have been reinserted.

B. Start the engine and wait for proper oil pressure to build.

C. Check to see if Diagnostic Code 24 OR 46 is ACTIVE with the engine running.

Neither code ACTIVE: The oil pressure sensor and ECM are currently operating correctly. Stop.

Either code ACTIVE: The oil pressure signal is reaching the ECM but the ECM is not reading it. Replace the ECM. Stop.

P-230: Dynamic Rack Controls Test

The primary function of the PEEC system is to electronically govern the engine. The PEEC governor senses engine speed (using the Engine Speed Sensor on the fuel pump camshaft), then controls the fuel rack to achieve a desired rpm. This test is used to determine if the PEEC governor is properly controlling the fuel rack.

Because this test requires monitoring several internal PEEC variables, the ECAP should be used rather than the DDT. The variables displayed on the ECAP "Status Display" which are used in this test are:

*Desired RPM

The rpm that the PEEC governor is trying to maintain. It is based on throttle position, engine speed, vehicle speed, Customer Specified Parameters, and certain diagnostic codes. *Desired Rack

The position where the ECM wants to move the rack, based on the PEEC governor trying to maintain "Desired RPM". "Desired Rack" will not go farther than the "FRC Rack" or "Rated Rack". *Actual Rack

The ECM's interpretation of the Rack Position Sensor signal represents actual position of the rack, assuming the sensor signal is valid. If the rack controls (solenoid, servo, sensor, etc.) are working properly, "Actual Rack" should follow "Desired Rack". *FRC Rack

The rack limit based on the Fuel-Air-Ratio Control (FRC). FRC Rack increases with boost pressure (as sensed by the Boost Sensor in the Transducer Module). This effectively limits the fuel injected into the cylinders until there is enough air present in the cylinders (as indicated by boost pressure) to cleanly burn the fuel. "Desired Rack" will never go past "FRC Rack". *Rated Rack

The rack limit which defines the horsepower and torque curves for the engine based on engine rpm. This limit is derived from maps programmed into the Personality Module by the factory.

Step 1. Verify Normal Rack Operation At Idle

A. Start the engine.

B. Monitor Desired RPM, Desired Rack, and Actual Rack on the ECAP "Status Display".

Desired RPM should be equal to the programmed Low Idle RPM and steady. The Actual Rack should follow Desired Rack within ± .5mm (Note that the lag in the ECAP "Status Display" causes some normal differences between the two readings). For a typical engine idling with normal accessory loads, both readings should be around 4.50 mm to 5.25 mm.

OK: PEEC is able to control the rack properly at idle. Continue with Step 2.

NOT OK: * If desired RPM is too high or unstable, follow P-211: Throttle Position Sensor Test. Stop.

* If the rack readings are not as specified, follow P-231: Rack Position Sensor Test, and P-232: Rack Solenoid (BTM) Test. Stop.

Step 2. Verify Normal Rack Operation Under Load

A. Load the engine, using either a dynomometer or a vehicle road test.

B. Monitor Desired Rack, Rated Rack, and FRC Rack.

Desired Rack should reach Rated Rack with the engine fully loaded.

OK: If the Rack Position Sensor is calibrated (refer to P-303: Rack Position Sensor Calibration), then PEEC is moving the rack to the specified position as it should. If problems persist, the cause IS NOT the rack controls. Refer to the procedure best describing the symptom. Otherwise, Stop.

NOT OK: * If Desired Rack is limited to FRC Rack, PEEC is sensing low boost pressure. Check for problems in the air intake system, then follow P-224: Boost Pressure Sensor Test.

* If Desired Rack is limited to some other value below Rated Rack, PEEC is intentionally limiting power or rpm for some reason. Refer to P-107: Low Power/Engine RPM Restricted/Will Not Reach VSL, to determine why. Stop.

P-231: Rack Position Sensor Test

The rack position sensor is magnetically attached to the fuel rack. The sensor is supplied with 8.0 volts for operation, and uses 5.0 volts for sensor reference. The signal output of 0.3 volts to 5.25 volts is read by the ECM as rack position of 0 to 16.5 mm [1990 and previous (8TC) engines], or 0 to 17.5 mm [1991 and subsequent (2EK) engines], and 0 to 17.5 mm for the 460 hp (5YG) engines.

Step 1. Check Electrical Connectors And Wiring

A. Check transducer module connector (J5/P5), and ECM/sensors connector (J3/P3) and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

B. Remove the rear cover from the governor.

C. Inspect rack sensor connector (J8/P8) and wiring for damage or incorrect attachment. Repair any damage. All wires in governor should be covered by protective sheathing.

Step 2. Check Rack Sensor Calibration

Refer to procedure P-303: Rack Position Sensor Calibration to check the rack sensor calibration. Recalibrate if needed. If sensor is unable to calibrate, proceed to Step 4.

Step 3. Check Rack Position Reading On ECAP Or DDT

A. Remove the Rack Solenoid (BTM).

B. Turn key ON, engine OFF.

C. Move the rack back and forth by hand and observe the "Rack Pos" reading on the ECAP or DDT's "Display Status" screen. The manual shutoff lever may have to be rotated clockwise to free up the rack.

The reading on the ECAP or DDT should be about 0.4 to 1.1 mm in the FUEL OFF position and increase to about 14.0 to 17.5 mm in the full FUEL ON position.

OK: The rack sensor is currently operating correctly. Stop.

NOT OK: Continue to next step.

Step 4. Check Voltage Supply To Rack Sensor

A. Connect a 5-pin 'T' at rack sensor connector (J8/P8).

B. Measure the 8V sensor supply voltage (Pin A to Pin B). and the 5V reference voltage (Pin C to Pin B).

The 8V sensor supply voltage should be 8 ± 0.4 VDC and the 5V reference voltage should be 5 ± 0.25 VDC.

OK: The sensor is receiving the proper supply voltages. Continue to next step.

NOT OK: There is a problem with the sensor supply voltage. Refer to P-221: Sensor Supply Voltage Test to troubleshoot.

Step 5. Check Rack Signal At Rack Sensor Connector

A. With the 5-pin 'T' still at the rack sensor connector (J8/P8), remove the rack signal wire from the transducer side (Pin D of J8).

B. Measure the rack signal voltage (Pin D to Pin B) of the 'T' while moving the rack back and forth by hand.

C. Reinsert Wire D in J8.

The voltage should be less than 2.0 VDC in the FUEL OFF position and smoothly increase to more than 4.0 VDC when the rack is moved all the way to FUEL ON.

OK: Rack sensor is OK. Continue to next step.

NOT OK: Rack sensor is not operating properly. Verify that the sensor plunger is in contact with the rack magnet, and that the epoxy on the magnet is in place. If so, replace the rack position sensor. Stop.

Step 6. Check Rack Signal At Transducer Module Connecto

A. Connect a 9-pin 'T' at transducer module connector (J5/P5).

B. Remove rack signal wire from connector (J5) (harness side).

C. Measure the rack signal voltage (Pin D to Pin B) of the 'T' while moving the rack back and forth by hand.

D. Reinsert Wire D in J5, remove the 'T', and reconnect transducer module connector (J5/P5).

The voltage should be less than 2.0 VDC in the FUEL OFF position and smoothly increase to more than 4.0 VDC when the rack is moved all the way into the FUEL ON range.

OK: The rack signal is getting through the transducer module. Continue to next step.

NOT OK: The rack signal is NOT getting through the transducer module. Check for damage in the connectors and wiring coming out of the transducer module. If none is found, replace the transducer module. Stop.

Step 7. Check Rack Signal At ECM

A. Connect a 9-pin 'T' at ECM/sensors connector (J3/P3).

B. Remove rack signal wire from ECM connector (Wire D of J3).

C. Measure the voltage between rack signal voltage (Pin D) and ground (Pin B) of the 'T' while moving the rack back and forth by hand.

D. Reinsert Wire D in J3.

The voltage should be less than 2.0 VDC in the FUEL OFF position and smoothly increase to more than 4.0 VDC when the rack is moved all the way into the FUEL ON range.

OK: The rack signal is reaching the ECM. Continue to next step.

NOT OK: The rack signal is NOT reaching the ECM. Inspect the wiring harness and connectors for damage or broken connection between the transducer and the ECM. Stop.

Step 8. Check ECM

A. Repeat Step 3 to determine if the ECM is reading the rack signal.

B. Check to see if Diagnostic Code 22 is ACTIVE.

The ECAP or DDT should show a valid rack position and Diagnostic Code 22 should NOT BE ACTIVE.

OK: The rack position sensor circuit is currently working correctly. Stop.

NOT OK: The ECM is not reading the rack signal. Recheck wires exiting the ECM to J3 for damage and repair as needed. If no damage is found, replace the ECM. Stop.

P-232: Rack Solenoid (BTM) Test

The Rack Solenoid [or brushless torque motor (BTM)] is used to move the engine's fuel rack. The BTM is spring-actuated to the FUEL OFF position. The BTM will move into the Fuel ON range when a voltage is applied.

Step 1. Check Electrical Connectors And Wiring

Check rack BTM connector (J10/P10) and ECM/solenoids connector (J4/P4) and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* inspect wiring for damage or abrasion.

* inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

Step 2. Remove And Inspect Rack Solenoid (BTM)

A. Remove the Rack Solenoid (BTM).

B. Check rack and rack servo for sticking or binding.

C. Inspect the BTM arm for damage, and for signs of binding in the rack servo sleeve.

The BTM arm should not be loose, and should encounter resistance from the spring as it is moved.

OK: Continue to next step.

NOT OK: Replace BTM if arm is damaged. Stop.

Step 3. Rack Solenoid (BTM) Sweep Test

A. Turn key ON, engine OFF.

B. Turn cruise control ON/OFF switch to ON.

C. Hold the cruise control SET/RESUME switch to the SET position and release after 1 second.

After a few seconds, the BTM arm should begin to sweep smoothly clockwise. Once it moves slightly past the dot on the BTM face plate, it should pause briefly, and then sweep back to the OFF stop.

OK: The rack BTM is currently operating properly. Stop.

NOT OK: Proceed to next step.

Step 4. Check BTM Resistance

A. Connect P10 (rack BTM side only) to a 3-pin 'T'.

B. Measure the resistance between BTM solenoid (Pin A) and ground (Pin B) of the 'T'.

The resistance should be between 1 and 2 ohms.

OK: BTM resistance is OK. Continue to next step.

NOT OK: BTM is defective. Replace BTM. Stop.

Step 5. Check Voltage To BTM During Sweep Test

A. Connect a 3-pin 'T' at rack solenoid (BTM) Connecter (J10/P10).

B. Measure the voltage between BTM solenoid (Pin A) and ground (Pin B) of the 'T'.

C. Turn cruise control ON/OFF switch to ON.

D. Hold and release the SET switch to begin the sweep test.

The voltage should begin at zero, increase to 3.6 ± 0.3 VDC and then decrease to zero VDC.

OK: The BTM is receiving voltage but is not moving. Replace the BTM. Stop.

NOT OK: The BTM is not receiving the proper voltages. Continue to next step.

Step 6. Check Voltage From ECM During Sweep Test

A. Connect a 5-pin 'T' at ECM/solenoids connector (J4/P4).

B. Measure the voltage between rack solenoid (BTM) signal (Pins C) and ground (Pin B) of the 'T'.

C. Turn cruise control ON/OFF switch to ON.

D. Hold and release the SET switch to begin the sweep test.

The voltage should begin at zero, increase to 3.6 ± 0.3 VDC and then decrease to zero VDC.

OK: The ECM is supplying proper voltages, but the BTM is not receiving them. Inspect the wiring and connectors between J10/P10 and J4/P4 for damage or a broken connection. Stop.

NOT OK: The ECM is not supplying the proper voltages. Verify that the ECM is getting battery power (P-210) and use the ECAP or DDT to verify that the cruise control switches are functioning properly (P-214). If they are OK, there is a problem with the ECM. Replace the ECM. Stop.

P-240: Dynamic Injection Timing Test

Besides governing the engine, PEEC also controls fuel injection timing to optimize performance and emissions. This test is used to determine if PEEC is controlling timing properly.

The amount of timing advance that PEEC desires is controlled by software in the Personality Module, and is dependent upon rpm, load, and other operating conditions. To control timing, PEEC increases voltage to the timing solenoid (BTM) to increase advance until it senses that actual timing advance is in the desired position.

The following are internal PEEC variables related to the injection timing which can be monitored on the ECAP status display:

* Static Timing Specification

Fixed number of degrees determined by design of the fuel pump camshaft (determines injection timing with no advance). Note that the value displayed is the specification for static timing, NOT an electrically measured value. To determine whether static timing is actually adjusted according to this specification, refer to P-301, Static Injection Timing Adjustment By Pin Method. * Desired Timing Advance

Degrees of advance beyond static that PEEC desires. It is a function of rpm, load, etc. to optimize performance and emissions. * Estimated Dynamic Timing

Estimated actual injection timing. Calculated internally by PEEC.

Est. Dyn Timing = Static Timing Spec + Actual Timing Advance + Port effect (.2 deg/100 rpm). * Actual Timing Advance

Degrees of advance beyond static, as measured by the timing position sensor (assumes that the timing position sensor is properly calibrated).

Step 1. Verify that "Actual" follows "Desired" Timing

A. Turn the engine OFF at the ignition switch.

B. Disconnect the Diagnostics Connector (J1/P1)(short connector) from the truck wiring harness and connect the ECAP.

C. Start the engine and run at low idle until the engine has warmed up enough to switch out of cold mode operation. Cruise control ON/OFF switch should be in the OFF position.

D. Select the Status Mode from the main menu on the ECAP service tool that displays timing advance, desired timing advance, static timing specification, and estimated dynamic timing. See Special Instruction, Form No. SEHS8741 for more information on the procedure to select the status screen.

E. Operate the engine at several different speeds. Record the difference between "Actual Timing Adv" and "Desired Timing Adv" displayed on the ECAP, after the engine speed stabilizes.

"Actual Timing Adv" should be within ± 0.30 degrees from "Desired Timing Adv"

OK: The timing advance mechanism is working properly.

NOT OK: The timing advance mechanism is NOT working properly. Follow P-241 to troubleshoot the Timing Position Sensor and P-242 to troubleshoot the Timing Solenoid (BTM). Also verify that the timing advance is not sticking or binding. Stop.

Step 2. Verify Actual Timing

Transducer In Position
(1) Injection transducer. (2) Fuel injection line for No. 6 cylinder.

A. Make reference to Special Instruction, Form No. SEHS8580 for the correct installation and operation of the 8T5300 Engine Timing Indicator Group. Install the injection transducer adapter and injection transducer in either fuel line number 1 or number 6 at the fuel injection pump. Install the TDC indicator in the flywheel housing and connect the cables to the Engine Timing Indicator and perform a calibration check as given in the Special Instruction.

Transducer In Position
(3) TDC magnetic transducer.

B. Use the Cruise Control Switches and run the engine at several different speeds in the PTO mode control. Make a record of the "Estimated Dynamic Timing" displayed on the ECAP and the timing angle displayed on the Engine Timing Indicator after the engine speed stabilizes.

The Estimated Dynamic Timing reading displayed on the ECAP should be equal to the timing angle reading displayed on the Engine Timing Indicator within ± 2.50 degrees.

OK: The timing advance actuator and timing position sensor are working correctly and the static injection timing is correctly set. Stop.

NOT OK: Follow P-301: Static Injection Timing Adjustment By Pin Method to set the static fuel injection timing, and P-302: Timing Position Sensor Calibration to calibrate the timing sensor. Repeat Step 2 after checking and adjusting the timing.

P-241: Timing Position Sensor Test

The PEEC engine timing advance is measured by the timing position sensor. The sensor measures the movement of the timing bellcrank. Note that the bellcrank moves with the actual timing advance, not just the timing advance servo spool. The sensor is supplied with an 8V supply voltage and 5V reference voltage from the ECM. The sensor's output ranges from 0.3 to 5.25 VDC which represents a timing advance of 0 - 35 Degrees.

Step 1. Check Electrical Connectors And Wiring

A. Remove the timing advance inspection cover to gain access to the timing position sensor.

B. Check the timing sensor connector (J7/P7) and ECM/sensors connector (J3/P3) and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion against inspection cover.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

Step 2. Check Timing Sensor Calibration

Refer to procedure P-302: Timing Position Sensor Calibration to check timing sensor calibration. Recalibrate if needed.

If sensor is unable to calibrate, proceed to Step 4.

Step 3. Check Timing Position Reading On ECAP Or DDT

A. Remove the timing solenoid for access.

B. Turn key ON, engine OFF.

C. Reaching into the timing solenoid mounting hole, move the sensor plunger downward (toward advance) by pulling forward on the vertical arm of the bellcrank.

D. Observe the "Timing Adv" reading on the ECAP or DDT's "Display Status" screen.

NOTE: Some force is required to overcome the spring acting on the bellcrank. If this method is too difficult, it may be necessary to remove the sensor for testing. The sensor must then be calibrated after it is reinstalled.

The reading on the ECAP or DDT should be less than 0.2 Deg with the bellcrank at rest (sensor plunger in), and greater than 15 Deg with the bellcrank rotated (sensor plunger extended).

OK: The timing sensor is currently operating correctly. Stop.

NOT OK: Continue to next step.

Step 4. Check Voltage Supply To Timing Sensor

A. Connect a 5-pin 'T' at timing sensor connector (J7/P7).

B. Measure the 8 V sensor supply voltage between (Pin A) and ground (Pin B) of the 'T' at J7/P7.

B. Measure the 5 V reference voltage between (Pin C) and ground (Pin B) of the 'T' at J7/P7.

The 8 V sensor supply should be 8 ± 0.4 VDC and the 5 V reference voltage should be 5 ± 0.25 VDC.

OK: The sensor is receiving the proper supply voltages. Continue to next step.

NOT OK: Follow procedure P-221: Sensor Supply Voltage Test, to troubleshoot the sensor supply voltage.

Step 5. Check Timing Sensor Operation

A. Remove timing signal wire (Pin E) from J7 (harness side).

B. Remove the timing solenoid.

C. Turn key ON, engine OFF.

D. Reaching into the timing solenoid mounting hole, move the sensor plunger OUT (by pushing the plunger down) while measuring the timing signal voltage (Pin E to Pin B).

The voltage should be less than 0.5 VDC when sensor is pushed in (timing retarded) and smoothly increase to more than 4.0 VDC when extended (timing advanced).

C. Re-insert Wire E in J7.

OK: Timing sensor is OK. Continue to next step.

NOT OK: Timing sensor is not operating properly. Replace the timing position sensor.

Step 6. Check Timing Signal Coming To ECM

A. Connect a 9-pin 'T' at J3/P3 (ECM/sensors connector).

B. Remove the timing signal wire (Pin J) from J3 (ECM side).

C. Measure the voltage between timing signal wire (Pin J) and ground (Pin B) of the 'T' while moving the sensor plunger by hand.

The voltage should be less than 0.5 VDC when sensor is pushed in (timing retarded) and smoothly increase to more than 4.0 VDC when extended (timing advanced).

D. Reinsert Wire J in J3.

OK: The timing signal is good coming to the ECM. Continue to the next step.

NOT OK: Inspect the wiring harness and connectors for damage or a broken connection between ECM and the timing sensor. Stop.

Step 7. Check ECM

A. Repeat Step 3 to determine if the ECM is reading the timing signal.

B. Check to see if Diagnostic Code 23 is ACTIVE.

The ECAP or DDT should show a valid timing advance and Diagnostic Code 23 should not be ACTIVE.

OK: The timing position sensor circuit is currently working correctly. Stop.

NOT OK: The ECM is receiving the timing signal, but is not reading it properly. Recheck wires exiting the ECM to J3 for damage. If none is found, replace the ECM. Stop.

P-242: Timing Solenoid (BTM) Test

The timing solenoid (or brushless torque motor [BTM]) is used to move the spool which advances and retards timing. The BTM is spring-actuated to the retarded position. The BTM will move into the advanced range when a voltage is applied.

Step 1. Check Electrical Connectors And Wiring

A. Remove the timing advance inspection cover to gain access to the timing position sensor.

B. Check the timing solenoid (BTM) connector (J6/P6) and ECM/solenoids connector (J4/P4) and wiring between them, being sure to:

* Check Connector lock rings.

* Perform 10 pound pull test on each pin or wire.

* Inspect wiring for damage or abrasion.

* Inspect connectors for damage or corrosion. Refer to P-201: Inspecting Electrical Connectors for details. Repair any damage, then continue with the next step.

Step 2. Remove And Inspect Timing BTM

A. Remove the timing BTM.

B. Inspect the BTM arm for damage.

The BTM arm should not be loose and should have resistance from the spring as it is moved toward the dot on the BTM face plate.

OK: Continue to next step.

NOT OK: Replace BTM if arm is damaged. Stop.

Step 3. Timing Solenoid (BTM) Sweep Test

A. Turn key ON, engine OFF.

B. Turn cruise control ON/OFF switch to ON.

C. Hold the cruise control SET/RESUME switch to the RESUME position and release after 1 second.

After a few seconds, the BTM arm should begin to sweep smoothly clockwise. Once it moves slightly past the dot on the BTM face plate, it should pause briefly, and then sweep back to the OFF stop.

OK: The timing BTM is currently operating correctly. Stop.

NOT OK: Continue to next step.

Step 4. Check BTM Resistance

A. Connect P6 (timing BTM side only) to a 3-pin 'T'.

B. Measure the resistance of the BTM (Pin A to Pin B) of the 'T'.

The resistance should be between 1 and 2 ohms.

OK: BTM resistance is OK. Continue to next step.

NOT OK: BTM is defective. Replace BTM. Stop.

Step 5. Check Voltage To BTM During Sweep Test

A. Connect J6 and P6 to the 3-pin 'T'.

B. Measure the voltage to the BTM (Pin A to Pin B of the 'T').

C. Turn cruise control ON/OFF switch to ON.

D. Hold and release the RESUME switch to begin the sweep test.

The voltage should begin at zero, increase to 3.6 ± 0.3 VDC and then decrease to 0 VDC again.

OK: The BTM is receiving voltage but is not moving. Replace the BTM. Stop.

NOT OK: The BTM is not receiving the proper voltage. Continue to the next step.

Step 6. Check Voltage From ECM During Sweep Test

A. Connect a 5-pin 'T' at J4/P4 (solenoids connector) at ECM.

B. Measure the voltage going to the timing BTM (Pin D to Pin B of the 'T').

C. Turn cruise control ON/OFF switch to ON.

D. Hold and release the RESUME switch to begin the sweep test.

The voltage should begin at zero, increase to 3.6 ± 0.3 VDC and then decrease to zero volts DC.

OK: The ECM is supplying proper voltages but the BTM is not receiving them. Inspect the wiring and harness connectors between the ECM and the timing BTM for damage or a broken connection. Stop.

NOT OK: The ECM is not supplying the proper voltages. Verify that the ECM is getting battery power (P-210), and use the ECAP or DDT to check that the cruise control switches are functioning properly (see P-214). If they are OK, there is a problem in the ECM. Replace the ECM. Stop.

P-250: Idle Shutdown Timer Test

The idle shutdown timer is a feature which helps improve fuel consumption by limiting idling time. It is available on engines equipped with personality modules built since April 1989. The timer may be programmed to shut down the idling engine after a period of time. This "shutdown time" is a Customer Specified Parameter, and may be programmed for any period from three to sixty minutes. Programming the time to zero disables the idle shutdown timer.

The timer is activated when the parking brake is set, vehicle speed is zero, and the engine is not under load. Ninety (90) seconds before the programmed time is reached, the diagnostic lamp will begin to flash rapidly. If the driver moves the clutch pedal or brake pedal during this 90 second period, the timer will be overridden until it is reset. On newer engines (those equipped with a Personality Module produced since May 1990), a Diagnostic Code 01 will be set when the driver overrides the timer using the clutch or brake.

If the timer is activated, and is allowed to shut down the engine, then a code 47 will be set. Both 01 and 47 merely record the event, and do not indicate a fault in PEEC.

NOTE: If any of the following codes are ACTIVE, the idle shutdown timer WILL NOT OPERATE:

*Diagnostic Code 31 (Loss of Vehicle Speed Signal)*Diagnostic Code 36 (Vehicle Speed Signal Out of Range)*Diagnostic Code 57 (Parking Brake Fault)

Follow the procedure indicated under the affected code, and correct that problem before attempting the test the idle shutdown timer.

Step 1. Verify Activation Of Idle Shutdown Timer

A. Install the ECAP or DDT.

B. Record the programmed idle shutdown time (must be between 3 and 60 minutes. If programmed to 0, timer is disabled).

C. Start the engine and verify that it is out of Cold Mode.

D. Set the parking brake.

E. Observe "Idle Shutdown" status on the ECAP or DDT.

With vehicle not moving and no load on the engine, "Idle Shutdown" status should change from "NOT ACTIVE" to "COUNTING".

OK: The ECM is seeing the proper conditions to activate the idle shutdown timer. Continue with next step.

NOT OK: The ECM is not seeing the proper conditions to activate the timer. Check the following:

*P-216: Parking Brake Switch Test*P-213: Vehicle Speed Signal Test*P-303: Rack Sensor Calibration.

Then repeat Step 1.

Step 2. Verify Driver Alert And Override

A. Repeat Step 1 above to activate the idle shutdown timer.

B. Observe the diagnostic lamp and the "Idle Shutdown" status during the ninety second period before the programmed shutdown time.

C. During the last ninety seconds, press either the service brake or clutch pedal to override the shutdown.

Ninety seconds before the scheduled shutdown, the status should change from "COUNTING" to "DRIVER ALERT", and the diagnostic lamp should begin flashing rapidly. After pressing the service brake or clutch pedal, the status should change to "OVERRIDDEN".

OK: The idle shutdown timer is operating normally. Stop.

NOT OK: If the diagnostic lamp is not flashing during the alert, refer to P-212: Diagnostic Lamp Test. If the ECM did not sense a change in clutch or brake status, refer to P-215: Service Brake And Clutch Switch Test. Then repeat this step.

P-251: Multi-Torque Test:

Multi-Torque is an optional feature available for certain PEEC engines. The feature is available only in certain Personality Modules. Refer to the section, Summary Of PEEC Personality Module Changes, to see which Personality Module part numbers have Multi-Torque.

310 Multi-Torque

The 310 Multi-Torque provides an otherwise standard 310 hp PEEC engine with two different torque curves. In all gears except top gear, the engine performs as a standard 310 hp PEEC. In the top gear, however, the engine is provided with the torque of a standard 310 hp at 1800 rpm, but with the peak torque of a 350 hp at 1150 rpm (see Illustration A).

PEEC determines whether the vehicle is in top gear by sensing the ratio of engine speed to road speed. If the ratio of engine speed/vehicle speed is less than 26.6, Multi-Torque is in effect. If it is greater than 26.6, the engine will perform like a standard 310 hp PEEC.

350 Multi-Torque

The 350 Multi-Torque works just like the 310 Multi-Torque, except for two key differences. First, The Multi-Torque curve provides the engine with the standard 350 hp torque at 1800 rpm, and with the peak torque of a 400 hp at 1200 rpm (see Illustration B). Second, the Multi-Torque is in effect in the top two gears, when the ratio of engine speed/vehicle speed is less than 37.6, Multi-Torque is in effect. If it is greater than 37.6, the engine will perform like a standard 350 hp PEEC.

Step 1. Repair Any Other Problems First

If there are other complaints or symptoms, refer to the procedure best describing the symptoms.

Step 2. Verify Proper Personality Module

Refer to the section, Summary Of PEEC Personality Module Changes, to verify that the part number stamped on the Personality Module is one which contains Multi-Torque.

Step 3. Verify Change In Rated Rack

A. Install vehicle on dyno or take for a road test.

B. Operate the vehicle in lower gears at around 1200 rpm (a load is not required).

C. On the ECAP "Status Display", read and record "Rated Rack".

D. Operate vehicle in top gear at 1200 rpm, and again read and record "Rated Rack".

Rated Rack in top gear should be at least 0.5 mm greater than the Rated Rack in the lower gears.

OK: Multi-Torque is working properly.

NOT OK: Verify that vehicle specifications are compatible with Multi-Torque. The ratio of engine rpm/vehicle mph should be less than 26.6 in top gear (engine rpm should be less than 1600 rpm at 60 mph in top gear to be compatible with Multi-Torque). If they are, check vehicle speed signal using P-213: Vehicle Speed Signal Test.

Illustration A. 3406B PEEC 310 Multi-Torque Lug Curve

Illustration B. 3406B PEEC 350 Multi-Torque Lug Curve

P-252: Power Demand Cruise Control

Power Demand Cruise Control (PDCC) is an optional feature available for certain PEEC engines installed in Navistar Chassis. Refer to section, Summary Of PEEC Personality Module Changes, to see which Personality Modules have PDCC. PDCC is only compatible with certain drive trains in certain Navistar chassis. Refer to sales information for compatibility.

PDCC provides an otherwise standard 310 hp PEEC engine with special torque curves. In normal operation (not in cruise), the engine performs as a standard 310 hp engine, except that torque is limited in deep lug (below 1100 rpm) in top gear due to drive train limitations. In cruise mode, the engine has the standard 310 hp torque at 1800 rpm, but has the peak torque of a 350 hp engine at 1150 rpm. Again, torque is limited in top gear while in deep lug due to drive train limitations (see Illustration A).

Illustration A. 3406B PEEC Power Demand Cruise Control Lug Curves

Step 1. Repair Any Other Problems First

If there are any other complaints or symptoms, refer to the procedure best describing the symptom.

Step 2. Verify Proper Personality Module

Refer to the section, Summary Of PEEC Personality Module Changes, to verify that the part number stamped on the Personality Module is one which contains PDCC.

Step 3. Verify Change In Rated Rack

A. Install vehicle on dyno or take for a road test.

B. Operate the vehicle in upper gears at around 1200 rpm with cruise OFF (a load is not required).

C. On the ECAP "Status Display", read and record "Rated Rack".

D. Operate vehicle in cruise control mode (turn CRUISE ON/OFF switch to ON, press and release SET switch), and again read and record "Rated Rack".

Rated Rack in cruise mode should be at least 0.5 mm greater than the Rated Rack when not in cruise.

OK: PDCC is working properly. Stop.

NOT OK: Verify cruise operation (cruise mode must be active, not just cruise switch ON). If cruise does not operate properly, see P-108 Cruise or PTO Does Not Function.