C13 Industrial Engine Caterpillar


Sensor Signal (Analog, Active) - Test

Usage:

C13 JR9
Use this procedure to troubleshoot the electrical system if a problem is suspected with the sensors. Also use this procedure if any one of the diagnostic codes in Table 1 is active or easily repeated.

Table 1
Diagnostic Trouble Codes 
J1939 Code  Code Description  Comments 
100-3  Engine Oil Pressure Sensor : Voltage Above Normal  The Electronic Control Module (ECM) detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
100-4  Engine Oil Pressure Sensor : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
101-3  Engine Crankcase Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
101-4  Engine Crankcase Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
108-3  Barometric Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
108-4  Barometric Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
109-3  Engine Coolant Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
Refer to the machine schematic for wiring and pinout information. 
109-4  Engine Coolant Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
Refer to the machine schematic for wiring and pinout information. 
157-3  Engine Injector Metering Rail #1 Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
157-4  Engine Injector Metering Rail #1 Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
411-3  Engine Exhaust Gas Recirculation Differential Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
411-4  Engine Exhaust Gas Recirculation Differential Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
1176-3  Engine Turbocharger #1 Compressor Inlet Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
1176-4  Engine Turbocharger #1 Compressor Inlet Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
1387-3  Auxiliary Pressure #1 : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
1387-4  Auxiliary Pressure #1 : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
2948-3  Engine Intake Valve Actuation System Oil Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
2948-4  Engine Intake Valve Actuation System Oil Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
3242-3  Aftertreatment #1 DPF Intake Gas Temperature : Voltage Above Normal  The code is logged.
The ECM detects voltage that is not in the acceptable range. 
3242-4  Aftertreatment #1 DPF Intake Gas Temperature : Voltage Below Normal  The code is logged.
The ECM detects voltage that is not in the acceptable range. 
3251-2  Aftertreatment #1 DPF Differential Pressure : Erratic, Intermittent, or Incorrect  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
3251-3  Aftertreatment #1 DPF Differential Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
3251-4  Aftertreatment #1 DPF Differential Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
3358-3  Engine Exhaust Gas Recirculation Inlet Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
3358-4  Engine Exhaust Gas Recirculation Inlet Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
3563-3  Engine Intake Manifold #1 Absolute Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
3563-4  Engine Intake Manifold #1 Absolute Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
3609-3  DPF #1 Intake Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
3609-4  DPF #1 Intake Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
4360-3  Aftertreatment #1 SCR Catalyst Intake Gas Temperature : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged. 
4360-4  Aftertreatment #1 SCR Catalyst Intake Gas Temperature : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged. 
5578-3  Engine Fuel Delivery Absolute Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
5578-4  Engine Fuel Delivery Absolute Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
5580-3  Engine Filtered Fuel Delivery Absolute Pressure : Voltage Above Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 
5580-4  Engine Filtered Fuel Delivery Absolute Pressure : Voltage Below Normal  The ECM detects signal voltage that is not in the acceptable range.
The code is logged.
The value of the parameter is set to a gauge pressure. 

The supply voltage is routed to terminal 1 of each sensor connector. The sensor return is routed to terminal 2 of each sensor connector. The sensor signal is routed to terminal 3 of each sensor connector. The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.

Diagnostics on the Caterpillar Electronic Technician (ET)

Wiggle Test - The Wiggle Test allows you to monitor the status of the signals from the sensors.

For additional information regarding the Wiggle Test, refer to the documentation that accompanies the Cat ET software.



Illustration 1g03049376

Note: The diagram above is a simplified schematic of the electrical circuit. The schematic is electrically correct. However, not all of the possible harness connectors are shown. Refer to the latest revision of the Electrical Schematic for the complete schematic.

Note: If a sensor is not listed in the above schematic, Refer to the machine schematic for wiring and pinout information.



Illustration 2g03743297

Locations of the sensors and the sensor connectors

Note: If a sensor is not listed in the above schematic, Refer to the machine schematic for wiring and pinout information.



Illustration 3g02110736
(1) Fuel rail pressure sensor


Illustration 4g02110738
(2) Intake manifold pressure sensor


Illustration 5g02110739
(3) NRS differential pressure sensor
(4) NRS absolute pressure sensor


Illustration 6g02110741
(5) Atmospheric pressure sensor


Illustration 7g02110742
(6) Crankcase pressure sensor


Illustration 8g02110743
(7) Oil pressure sensor


Illustration 9g02110744
(8) Fuel pressure sensor at the inlet of the tertiary filter
(9) Fuel pressure sensor at the outlet of the tertiary filter


Illustration 10g02211287
CEM (typical)
(1) Absolute pressure sensor for the DPF

Table 2
Troubleshooting Test Steps  Values  Results 

1. Check for Diagnostic Codes

A. Establish communication between Caterpillar Electronic Technician (ET) and the ECM . Refer to Troubleshooting, "Electronic Service Tools", if necessary.

B. Turn the keyswitch to the ON position.

C. Look for a -3, or -4 active or logged codes:
 

Diagnostic code
 

Result: A -3 diagnostic code is active.

Proceed to Test Step 2.

Result: A -4 diagnostic code is active.

Proceed to Test Step 3.

Result: A 3251-2 diagnostic code is active.
Proceed to Test Step 6.
 

2. Create a Short at the Sensor Connector

A. Use a jumper wire in order to create a short between terminal 3 (signal) and terminal 2 (sensor return) at the sensor connector.

B. Turn the keyswitch to the ON position.

C. Monitor the diagnostic codes on Cat ET. Check for an active -4 diagnostic code for the suspect sensor.

D. Turn the keyswitch to the OFF position.
 

Short created
 

Result: A -4 diagnostic code became active after creating the short at the sensor connector.

The wiring is OK. Replace the sensor.
Verify that the problem is resolved.

Result: A -4 diagnostic code does not become active for the suspect sensor.

Proceed to Test Step 4.
 

3. Create an Open at the Suspect Sensor Connector

A. Turn the keyswitch to the OFF position.

B. Disconnect the sensor connector of the suspect sensor with the active -4 diagnostic code.

C. Turn the keyswitch to the ON position.

D. Monitor the diagnostic codes on Cat ET. Check for an active -3 diagnostic code for the suspect sensor.

E. Turn the keyswitch to the OFF position.
 

Create an Open 

Result: A -3 diagnostic code became active after disconnecting the sensor.

The wiring is OK. Replace the sensor.

Verify that the problem is resolved.

Result: A -3 diagnostic code did not became active after disconnecting the sensor.

Proceed to Test Step 4.
 

4. Check the 5 VDC Supply Voltage at the Sensor Connector

A. Turn the keyswitch to the ON position.

B. Measure the voltage between pin 1 and pin 2 at the suspect sensor.
 

Test passed 

Result: The supply voltage is approximately 5.0 ± 0.2 VDC

Connect the sensor and then proceed to Test Step 5

Result: The supply voltage is not approximately 5.0 ± 0.2 VDC.

There is a short in the harness to the battery. Repair the wiring or replace the harness

Verify that the problem is resolved.
STOP
 

5. Perform the Wiggle Test

Carefully following this procedure is the best way to identify the root cause of an intermittent problem.

A. Turn the keyswitch to the ON position.

B. Use CAT ET to run the "Wiggle Test".

C. Slowly wiggle the wiring and the connectors between the P2 connector and the sensor. Pay particular attention to the wiring near each connector. Be sure to wiggle all of the wiring.
As you wiggle the wiring look for these problems.
1. Loose connectors or damaged connectors
2. Moisture on the connectors or the wiring
3. Damaged that is caused by excessive heat
4. Damage that is caused by chafing
5. Improper routing of wiring
6. Damaged insulation
 

Test passed 

Result: The wiring failed the Wiggle Test.

There is a problem with the wiring. Repair the wiring or replace the wiring.

Verify that the problem is resolved.

STOP

Result: The wiring passed the Wiggle Test.

The problem may be intermittent. Inspect the wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect".

If the wiring looks OK perform the following procedure.

1. Turn the keyswitch to the OFF position.
2. Disconnect the connectors. Carefully inspect the terminals for proper installation. Make sure that each terminal is clean and dry.
3. Insert a pin into each socket. Verify that each socket grips the pin firmly. Repair any problems.
4. Connect all connectors.
5. Verify that the problem is resolved.
6. Return the unit to service.
STOP
 

Table 3

6. Inspect the DPF Differential Pressure Lines, Fittings, and Manifold

A. Ensure that the DPF differential pressure lines are connected.

B. Ensure that the DPF differential pressure lines, fittings, and manifold are free from obstructions. Make sure that moisture has not frozen in the lines, fittings, and manifold.

Note: The 3251-2 will not activate for several hours if the ambient temperature is below 7° C (45° F) or if an active regeneration has not been performed. If troubleshooting a 3251-2 and ambient temperature is below 7° C (45° F), perform a "Manual DPF regeneration" after completing the repair to verify that the problem has been resolved.
 

Lines inspected
 

Result: The DPF differential pressure lines, fittings, and manifold are connected and free from obstructions.

Proceed to Test Step 7

Result: The DPF differential pressure lines are not connected or the lines, fittings, and manifold have obstructions.

Repair or replace the DPF differential pressure line. Clear all codes. Return the engine to service.
STOP
 

7. Inspect the Electrical Connector for the DPF Differential Pressure Sensor

A. Check the connector for the differential pressure sensor.

Note: The 3251-2 will not activate for several hours if the ambient temperature is below 7° C (45° F) or if an active regeneration has not been performed. If troubleshooting a 3251-2 and ambient temperature is below 7° C (45° F), perform a "Manual DPF regeneration" after completing the repair to verify that the problem has been resolved.
 

Connectors inspected
 

Result: Connect the connectors to the correct sensors. Verify that the problem is resolved. Clear all codes. Return the engine to service.


STOP
 

Complete the procedure in the order in which the steps are listed.

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