G3520B Industrial Engines Caterpillar

Prelubrication - Test

Usage:

System Operation Description:

Use this procedure to troubleshoot a suspected problem with the circuit that is for the engine prelube solenoid or use this procedure if one of the diagnostic codes in Table 1 is active or easily repeated.

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Table 1
Diagnostic Codes Table
Description	Conditions which Generate this Code	System Response
E233(3) Low Engine Pre-Lube Pressure	The prelubrication pressure is outside the expected pressure for the programmed delay time.	The code is logged. The alarm output is activated. The engine is prohibited from being started. The Electronic Control Module (ECM) continues to energize the prelube pump relay.
338-5 Engine Pre-Lube Pump Relay : Current Below Normal	While the output driver is off, the ECM detects an open in the circuit for the engine prelube solenoid for more than five seconds.	The code is logged. The alarm output is activated.
338-6 Engine Pre-Lube Pump Relay : Current Above Normal	While the output driver is on, the ECM detects a short in the circuit for the engine prelube solenoid for more than five seconds.	The code is logged. The alarm output is activated. The output driver automatically resets and the output driver continues to try to activate the circuit component.
339-5 Engine Pre-Lube Pressure Switch : Current Below Normal	The ECM detects an open in the circuit for the circuit for the manual prelubrication switch.	The code is logged. The alarm output is activated.

Note: The prelubrication system is an option on these engines. If Caterpillar did not supply the prelube system, the electronic control for the prelube system is disabled. The above diagnostic and event codes are also disabled.

If the "Engine Pre-Lube Time Out Period" parameter is programmed for a time period of zero seconds, the diagnostic and event codes that are mentioned above are disabled. The engine will crank without the prelubrication.

In order for the prelube system to be enabled, the "Engine Pre-Lube Time Out Period" parameter must be programmed for 120 seconds.

The prelube pump will not operate if the emergency stop button is activated or if the engine speed is greater than 0 rpm.

During the prestart, the ECM will energize the prelube pump before cranking the engine in order to provide lubrication to the engine bearings. If the prelubrication of the engine is required, the ECM will provide +Battery voltage to the prelube relay. The prelube relay provides pressurized air or gas to the prelube pump motor. The prelube pump pressurizes the engine's lubrication system with oil. After activation, the prelube system will operate until one of the following occurrences:

Activation of the prelubrication pressure switch
Completion of the programmed "Engine Pre-lube Time Out Period"
Activation of the emergency stop button

The ECM monitors the prelubrication pressure switch in order to verify adequate lubrication of the engine prior to start-up. The pressure switch is normally open. The pressure switch closes when the prelube pump raises the engine oil pressure to 9 ± 3 kPa (1.3 ± 0.4 psi). When the pressure switch closes, sufficient oil pressure has been detected in order to initiate engine starting. After the pressure switch closes, the prelube pump continues to operate for a duration that is equal to the programmed "Engine Pre-Lube Time Out Period". The engine starting sequence continues when the engine prelube sequence is complete.

If the ECM does not detect a signal from the pressure switch within the programmed period of time, the ECM monitors the engine oil pressure sensor in order to determine whether lubrication has occurred. If the prelubrication does not occur, an E233 Low Engine Pre-lube Pressure is generated. The starting sequence is terminated.

The prelube pump can also be operated with a manual switch that can be installed by the customer as an option. When the switch is closed, a +Battery signal is sent to the ECM. The ECM provides +Battery voltage to the engine prelube solenoid until one of these conditions occur:

Activation of the prelubrication pressure switch
Deactivation of the manual prelube switch that can be installed by the customer as an option
Activation of the emergency stop button

The prelubrication system may also operate after shutdown. This ensures that the shaft bearings for the turbocharger have adequate lubrication during an engine shutdown. When the engine reaches 0 rpm, the output for the engine prelube solenoid may be energized for a period that is equal to the "Engine Post-Lube Duration" parameter setting. The postlube cycle can be disabled by setting the "Engine Post-Lube Duration" parameter setting to "0".

The troubleshooting procedure may generate additional diagnostic codes. Continue troubleshooting the cause of the original diagnostic code. Clear the diagnostic codes after the problem is resolved.

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Illustration 1	g01572659
Schematic of the prelubrication system

Test Step 1. Inspect the Electrical Connectors and the Wiring

Set the engine control to the OFF/RESET position.

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Illustration 2	g01435727
Location of the components for the prelubrication system (1) Prelube pump (2) Engine prelube solenoid (3) Prelubrication pressure switch

Thoroughly inspect the mechanical condition of prelubrication pump (1). Also, check the condition of the lines group from the air supply to the exhaust piping that is for the prelubrication system.

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Illustration 3	g01435742
Locations of the connectors for the NO_X sensor (typical left side engine view) (4) J2/P2 ECM connectors for the master ECM (5) J1/P1 ECM connectors for the master ECM (6) J5/P5 customer connector (4) P10 connector for the harness to the optional control panel

Thoroughly inspect the condition of the connectors for engine prelube solenoid (2) and pressure switch (3). Inspect the condition of ECM connectors (4) and (5). Also, thoroughly inspect the condition of connectors (6), (7), and (8). Refer to Troubleshooting, "Electrical Connectors - Inspect".

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Illustration 4	g01438180
Terminal locations on the P1 ECM connector for the prelubrication system (P1-30) Prelubrication pressure switch (P1-31) Digital Return (P1-56) Manual prelube input

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Illustration 5	g01438182
Terminal locations on the P2 ECM connector for the prelubrication system (P2-12) Engine prelube solenoid (P2-22) Return

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Illustration 6	g01438187
Terminal locations on the P5 customer connector for the prelubrication system (P5-58) Manual prelube switch (P5-59) Engine prelube solenoid

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Illustration 7	g01438189
Terminal locations on the P8 control harness connector for the prelubrication system (P8-A) Engine prelube solenoid (P8-B) Return (P8-L) Prelubrication pressure switch (P8-V) Digital Return

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Illustration 8	g01572833
Terminal locations on the P10 connector for the prelubrication system (P10-c) Prelube light (P10-T) Manual prelube switch

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Illustration 9	g01155187
Terminal locations at the connector for the prelubrication pressure switch and the engine prelube solenoid (Terminal 1) Signal (Terminal 2) Return

Perform a 45 N (10 lb) pull test on each of the wires in the circuit for the prelube system.

Check the torque of the allen head screws for each of the ECM connectors and for the customer connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.

Check the harness and the wiring for abrasion and for pinch points from the battery to the junction box. Check that the fuses for the circuit are not blown.

Expected Result:

All connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.

Results:

OK - All connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points. The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - At least one of the connectors, pins, or sockets is not connected properly. At least one connector or wire has corrosion, abrasion, and/or pinch points. The components are not in good condition and/or at least one connection is improper.
Repair: Perform the necessary repairs and/or replace parts, if necessary.
STOP

Test Step 2. Check for Diagnostic Codes

Establish communication between Cat ET and the engine ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary.

Observe the "Diagnostics" screen on Cat ET.
Note: If there is an active 338-5 Engine Pre-Lube Pump Relay current below normal, proceed to the "Results" for this Test Step. Otherwise, continue this procedure.
Determine whether the following diagnostic codes are logged:
- 338-5 Engine Pre-Lube Pump Relay current below normal
- 338-6 Engine Pre-Lube Pump Relay current above normal
- 339-5 Engine Pre-Lube Pressure Switch current below normal

Expected Result:

None of the diagnostic codes are logged.

Results:

OK - None of the codes are logged.
Repair: There may be an intermittent electrical problem in the harness or in a connector. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect".
STOP
Not OK (338-5 diagnostic code) - A 338-5 diagnostic code was activated. This can be caused by an actual open circuit or by a short circuit to the +Battery side. Proceed to Test Step 3.
Not OK (338-6 diagnostic code) - After the prelube pump was energized, a 338-6 diagnostic code was generated. Proceed to Test Step 7.
Not OK (339-5 diagnostic code) - There is a logged 339-5 diagnostic code. There is a problem with the circuit for the prelubrication pressure switch. Proceed to Test Step 9.

Test Step 3. Check for a Short Circuit to the +Battery Side

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Gaseous fuel is present. Personal Injury or Death can result from an open flame or spark igniting the gaseous fuel causing an explosion and/or fire. Always use a gas detector to determine the presence of gaseous fuel when maintaining and servicing. Contact you local gas provider immediately for assistance in the event of a leak.

Note: Open sparks can be generated during this test.

Make sure that no combustible gas is present in the surrounding atmosphere.

Ensure that the engine control is in the STOP position.

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High voltage. Power source must be disconnected before working on equipment. Failure to disconnect power source could result in injury or death.

Verify that the pressurized air for the prelube pump motor is disconnected.

Disconnect the harness connector for the engine prelube solenoid. Then connect the connector. Listen for an audible click from the solenoid.
If the ambient noise is too loud, touch the solenoid when the connector is connected in order to feel the vibration. The solenoid will vibrate when the solenoid is de-energized and energized.

Expected Result:

There is an audible click and/or vibration when the connector is disconnected and connected. The solenoid is energized when the engine control is in the STOP position.

Results:

OK - There is an audible click and/or vibration when the connector is disconnected and connected. The solenoid is receiving power when the engine control is in the STOP position. There is probably a short circuit to the +Battery side in a connector or a wiring harness. Proceed to Test Step 4.
OK - There is no audible click and/or vibration when the connector is disconnected and connected. There is no short circuit to the +Battery side. There is an open circuit. Proceed to Test Step 5.

Test Step 4. Determine the Cause of the Energized Solenoid

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Note: Open sparks can be generated during this test.

Remove the wires from terminal locations P2-12 and P2-22 at the ECM connector.

Set the engine control to the STOP position.

Disconnect the harness connector for the engine prelube solenoid. Then connect the connector. Listen for an audible click from the solenoid.
If the ambient noise is too loud, touch the solenoid when the connector is connected in order to feel the vibration. The solenoid will vibrate when the solenoid is de-energized and energized.

Expected Result:

There is no audible click and/or vibration when the connector is disconnected and connected. The solenoid is not energized when the engine control is in the STOP position.

Results:

OK - There is no audible click and/or vibration when the connector is disconnected and connected. The solenoid is not energized when the ECM is disconnected from the circuit.
Repair: Perform the following steps:
1. Set the engine control to the OFF/RESET position.
1. Restore the wiring to the P2 ECM connector. Pull on the wires in order to verify proper installation of the terminals.
1. Temporarily install a new ECM. Refer to Troubleshooting, "ECM - Replace".
  If the problem is resolved with the new ECM, install the original ECM and verify that the problem returns. If the new ECM operates correctly and the original ECM does not operate correctly, replace the original ECM. Refer to Troubleshooting, "ECM - Replace".
STOP
Not OK - There is no audible click and/or vibration when the connector is disconnected and connected. The solenoid is energized when the ECM is disconnected. There is a short circuit to the +Battery side in the engine harness.
Repair: Repair the connector and/or wiring, when possible. Replace parts, if necessary. Verify that the problem is resolved.
STOP

Test Step 5. Create a Short Circuit at the Harness Connector for the Engine Prelube Solenoid

Set the engine control to the OFF/RESET position.

Fabricate a jumper wire that is long enough to create a test circuit across the connector at the engine prelube solenoid. Crimp connector sockets to each end of the jumper wire.

Disconnect the harness connector for the engine prelube solenoid.

Connect the jumper wire between the two terminals on the harness connector for the engine prelube solenoid.

Set the engine control to the STOP position.

Note: The 338-5 diagnostic code can only be detected when the ECM output for the engine prelube solenoid is off. The output is normally off when the engine control is in the STOP position and when the pressure switch is CLOSED.

Wait for 30 seconds and use the "Active Diagnostic" screen of Cat ET to look for a 338-5 diagnostic code.

Expected Result:

A 338-5 diagnostic code was not generated when the jumper wire was installed.

Results:

OK - A 338-5 diagnostic code was not generated when the jumper wire was installed. The harness and the ECM are OK. There is a problem with the solenoid.
Repair: Perform the following procedure:
1. Set the engine control to the OFF/RESET position.
1. Remove the jumper wire from the harness connector for the engine prelube solenoid.
1. Inspect the terminals of the connectors for the engine prelube solenoid. Check the terminals for damage, for moisture, and for corrosion. Make repairs, as needed.
If the problem is not resolved, replace the solenoid.
STOP
Not OK - A 338-5 diagnostic code was generated when the jumper wire was installed. There is an open circuit in a harness or a problem with the ECM. Proceed to Test Step 6.

Test Step 6. Create a Short Circuit at the ECM

Set the engine control to the OFF/RESET position.

Fabricate a jumper wire that is long enough to create a test circuit across the ECM connector. Crimp connector sockets to each end of the jumper wire.

Remove the wires from terminal locations P2-12 and P2-22 at the ECM connector.

Install the jumper wire between terminal locations P2-12 and P2-22. Pull on the jumper wire in order to verify proper installation.

Set the engine control to the STOP position.

Wait for 30 seconds and use the "Active Diagnostic" screen of Cat ET to look for an active 338-5 diagnostic code.

Expected Result:

There is no active 338-5 diagnostic code.

Results:

OK - When the jumper wire was installed, there was no active 338-5 diagnostic code. The ECM detects the jumper wire at the P2 connector. However, the ECM did not detect the jumper wire at the engine prelube solenoid. There is a problem with the wiring between the P2 connector and the engine prelube solenoid. There may be a problem with a connector.
Repair: Perform the following procedure:
1. Set the engine control to the OFF/RESET position.
1. Remove the jumper wire from the P2 connector.
1. Restore the wiring at the P2 ECM connector to the original configuration. Pull on the wires in order to verify proper installation of the terminals.
1. Repair the wiring, when possible. Replace parts, if necessary.
STOP
Not OK - When the jumper wire was installed, a 338-5 diagnostic code was activated. The ECM did not detect the jumper wire. There is a problem with the ECM.
Repair: Perform the following procedure:
1. Set the engine control to the OFF/RESET position.
1. Remove the jumper wire from the P2 connector.
1. Restore the wiring at the P2 ECM connector to the original configuration. Pull on the wires in order to verify proper installation of the terminals.
1. Replace the ECM according to Troubleshooting, "ECM - Replace". Verify that the problem is resolved.
STOP

Test Step 7. Create an Open Circuit at the Harness Connector for the Engine Prelube Solenoid

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High voltage. Power source must be disconnected before working on equipment. Failure to disconnect power source could result in injury or death.

Set the engine control to the OFF/RESET position.

Disconnect the harness connector for the engine prelube solenoid.

Set the engine control to the STOP position.

Clear the logged 338-6 diagnostic code.

Verify that the pressurized air for the prelube pump motor is disconnected.

Note: The 338-6 diagnostic code can only be detected when the ECM output for the engine prelube solenoid is on. The output is normally on when the engine control is in the START position and the pressure switch is open.

Place the engine control in the START position for at least 30 seconds.

Set the engine control to the OFF/RESET position.

Look for a logged 338-6 diagnostic code.

Expected Result:

After the engine prelube solenoid was energized, there was no logged 338-6 diagnostic code.

Results:

OK - When the solenoid was connected, a 338-6 diagnostic code was generated. When the solenoid was disconnected, no 338-6 diagnostic code was generated. There is a problem with the solenoid.
Repair: Perform the following procedure:
1. Set the engine control to the OFF/RESET position.
1. Inspect the connections of the solenoid for damage and/or corrosion.
1. Perform the necessary repairs.
If the problem is not resolved, replace the solenoid.
STOP
Not OK - When the solenoid was connected, a 338-6 diagnostic code was generated. When the solenoid was disconnected, the 338-6 diagnostic code remained. There is a problem with the wiring or with the ECM. Proceed to Test Step 8.

Test Step 8. Create an Open Circuit at the ECM

Remove the wire from terminal location P2-12 at the P2 ECM connector.

Set the engine control to the STOP position.

Clear the logged 338-6 diagnostic code.

Verify that the pressurized air for the prelube pump motor is disconnected.

Place the engine control in the START position for at least 30 seconds.

Set the engine control to the OFF/RESET position.

Look for a logged 338-6 diagnostic code again.

Expected Result:

The 338-6 diagnostic code was not generated.

Results:

OK - When the output to the solenoid was disconnected from the P2 ECM connector, the 338-6 diagnostic code was not generated. There is a problem with the wiring between the P2 ECM connector and the engine prelube solenoid. The problem could be in a connector.
Repair: Perform the following procedure:
1. Restore the wiring at the P2 ECM connectors. Pull on the wire in order to verify proper installation of the terminal.
1. Repair the harness, when possible. Replace the harness, if necessary.
STOP
Not OK - A 338-6 diagnostic code was generated when the wiring was disconnected from the P2 ECM connector. There seems to be a problem with the ECM.
Repair: Perform the following procedure:
1. Set the engine control to the OFF/RESET position.
1. Restore the wiring at the P2 ECM connectors. Pull on the wire in order to verify proper installation of the terminal.
1. Replace the ECM according to Troubleshooting, "ECM - Replace". Verify that the problem is resolved.
STOP

Test Step 9. Check for the Proper Operation of the Prelubrication Pressure Switch

Set the engine control switch to the OFF/RESET position.

Disconnect the prelubrication pressure switch from the engine harness. Remove the prelubrication pressure switch from the cylinder block.

Install a tee that has 1/4-18 NPTF threads into the cylinder block's port for the pressure switch.
If a tee cannot be installed into the port, install a flexible hose that has the appropriate fitting into the port and attach the tee to the hose.
Install the pressure switch into one side of the tee. Attach a pressure gauge to the other side of the tee.

Connect an ohmmeter to the terminals on the pressure switch's connector. Measure the resistance between the terminals on the pressure switch's connector. Wiggle the switch's harness as you measure the resistance in order to check for an intermittent problem with the harness.

Verify that the pressurized air for the prelube pump motor is disconnected.

Place the engine control in the START position for at least 30 seconds.
Confirm that the prelube pump is operating during this test.

Observe the pressure gauge. Check for a rise in the engine oil pressure. When the engine oil pressure rises to 9 ± 3 kPa (1.3 ± 0.4 psi), use a multimeter to check for continuity across the terminals of the pressure switch. Wiggle the switch's harness as you measure the resistance in order to check for an intermittent problem with the harness.

Set the engine control switch to the OFF/RESET position.

Expected Result:

When the prelube pump is off, the resistance is an open circuit. When the prelube pump is on and the engine oil pressure increased above 9 ± 3 kPa (1.3 ± 0.4 psi), the switch closes and the circuit is continuous.

Results:

OK - When the prelube pump is off, an open circuit is measured across the terminals of the switch. When the prelube pump is on and the engine oil pressure rose to 9 ± 3 kPa (1.3 ± 0.4 psi), the switch closes and the circuit is continuous.
Repair: The pressure switch is operating properly. There may be a problem in the engine harness. Set the engine control switch to the OFF/RESET position.Remove the pressure switch and the pressure gauge from the tee. Remove the tee from the cylinder block's port. Install the pressure switch into the cylinder block's port. Tighten the pressure switch according to Specifications, "Prelube Pressure Switch" in order to check for a problem in the harness.
Proceed to Test Step 10.
Not OK - At least one of the resistance measurements is not correct.
Repair: The contacts of the prelubrication pressure switch are stuck in the closed position or the contacts of the switch are stuck in the open position. Remove the pressure switch and the pressure gauge from the tee. Remove the tee from the cylinder block's port.Install a new prelubrication pressure switch. Tighten the pressure switch according to Specifications, "Prelube Pressure Switch". Connect the engine harness to the switch.Verify that the problem is resolved.
STOP
Not OK - The engine oil pressure did not rise to 9 ± 3 kPa (1.3 ± 0.4 psi) with the prelubrication pump in operation. The engine oil is blocked from the passages to the port for the pressure switch.
Repair: Set the engine control to the OFF/RESET position.Determine the cause of the obstruction in the passages for the engine oil. Make the necessary repairs.
STOP

Test Step 10. Check the Engine Harness

Ensure that the engine control is in the OFF/RESET position.

Fabricate a jumper wire that is long enough to create a test circuit across the terminals of the harness connector for the prelubrication pressure switch. Crimp connector pins to each end of the jumper wire.

Install the jumper wire across terminals 1 and 2 of the engine harness connector for the prelubrication pressure switch.

Use a wire removal tool to remove the wires from terminal locations P1-30 and P1-31 at the ECM connector. Measure the resistance between the wires for the prelubrication pressure switch at the ECM. Wiggle the engine harness as you measure the resistance in order to check for an intermittent problem. Be sure to wiggle the harness near the connectors.

Remove the jumper wire and measure the resistance between the wires for the prelubrication pressure switch at the ECM. Wiggle the engine harness as you measure the resistance in order to check for an intermittent problem. Be sure to wiggle the harness near the connectors. Measure the resistance between each of the wires and the engine ground stud.

Expected Result:

The circuit for the prelubrication pressure switch is continuous with the jumper wire in place. The circuit for the prelubrication pressure switch is not continuous when the jumper wire is removed.

Results:

OK - The circuit has continuity with the jumper wire in place. The circuit for the prelubrication pressure switch does not have continuity when the jumper wire is removed.
Repair: The harness and the connectors are OK. There may be an intermittent electrical problem in the harness or in a connector. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect".
STOP
Not OK - An open circuit or a short circuit is detected in the circuit for the prelubrication pressure switch.
Repair: There is a problem with the engine harness. Repair the connector(s) and/or the wiring, when possible. Replace the harness, if necessary. Verify that the problem is resolved.
STOP