3512B Petroleum Engines with the ADEM 2 Electronic Control Module Caterpillar

The Electronic Control Module (ECM) has the ability to automatically prelube the engine. This may increase the life of certain engine parts.

The following conditions are possible: OFF, ON, COMPLETED and DISABLED.

The "OFF" condition is valid when an engine shutdown is active.

The "ON" condition is valid when an engine shutdown is not active and the "Start/Run/Stop Switch" is activated.

The "COMPLETED" condition is valid when the engine prelube duration is reached or when the engine prelube pressure switch is activated.

The "DISABLED" condition is valid when the engine prelube duration is programmed to 0.

The prelube function will be aborted when one of the following conditions occur:

• The engine prelube pressure switch is activated.

• The User defined engine prelube duration has been reached.

Illustration 1	g00894813
Typical example

Test Step 1. Check for Connector Damage.

1. Turn the main breaker to the OFF position.

2. Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.

3. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.

4. Check the ECM connector (allen head screw) for the proper torque of 6.0 N·m (55 lb in).

5. Check the customer connector (allen head screw) for the proper torque of 2.25 ± 0.25 N·m (20 ± 2 lb in).

6. Check the harness and the wiring for abrasion and pinch points.

Expected Result:

The connectors and wiring should be free of the following problems: damage, corrosion, abrasion and incorrect attachment.

Results:

• Not OK - The wiring and connectors are okay.

  Repair: Repair the connectors or wiring and/or replace the connectors or wiring.

  STOP

• OK - The wiring and/or connectors need repair. Proceed to test step 2.

Test Step 2. Check the Engine Prelube Pressure Switch.

1. Turn the engine control to the OFF position.

2. Ensure that the Prelube Override Switch is OPEN.

3. Disconnect ECM connector J1/P1.

4. Measure the resistance between the engine prelube pressure switch P1-19 and the Digital Return P1-29.

5. Reconnect the ECM connector P1.

Expected Result:

The resistance should be greater than 20,000 ohms.

Results:

• OK - The resistance is greater than 20,000 ohms. The engine prelube pressure switch is not active. Proceed to test step 3.

• Not OK - The resistance is less than 20,000 ohms. The engine prelube pressure switch is active. Verify that the engine does not have a residual oil pressure that is high enough to activate the switch. If there is no residual oil pressure the switch is not operating correctly or there is a problem with the wiring. Proceed to test step 4.

Test Step 3. Check the Status of the Prelube Switch on the Caterpillar Electronic Technician (ET).

1. Start the Cat ET.

2. Turn the engine control to the ON position.

3. The engine should not be running.

4. Observe the parameters for the engine prelube pressure switch and the parameter for the start/run/stop switch.

Expected Result:

The parameter for the engine prelube should display "OFF". The parameter for the start/run/stop switch should display "OFF".

Results:

• OK - The status parameters are correct. Proceed to test step 5.

• Prelube Disabled -

  Repair: Set the engine prelube duration to a value that is greater than zero. Restart this test.

  STOP

• Start/Run/Stop Switch NOT OFF -

  Repair: There is a problem in the wiring to the start/run/stop switch. Perform the diagnostic functional test Troubleshooting, ""Start/Run/Stop Switch"".

  STOP

Test Step 4. Check the Engine Prelube Pressure Switch.

1. Turn the engine control to the OFF position.

2. Disconnect the wires from terminal 1 and terminal 2 of the engine prelube pressure switch.

3. Measure the resistance between terminal 1 and terminal 2 of the engine prelube pressure switch.

Expected Result:

The resistance should be greater than 20,000 ohms.

Results:

• OK - The resistance is greater than 20,000 Ohms.

  Repair: The problem is in the wires and/or connectors between the ECM connector J1/P1 and the engine prelube pressure switch. Repair the connectors or wiring and/or replace the connectors or wiring.

  STOP

• Not OK - The resistance is less than 20,000 ohms. There is a problem with the engine prelube pressure switch.

  Repair: Install a new switch. Verify that the problem is no longer present.

  STOP

Test Step 5. Check the Status of the Engine Prelube Pressure Switch on Cat ET.

1. Turn the engine control to the ON position.

2. Turn the "Start/Run/Stop Switch" to the START position.

3. View the parameters for the engine prelube pressure switch and the parameters for the start/run/stop switch. View the parameters before the engine prelube duration expires. View the parameters before the engine prelube pressure switch activates.

   Note: If necessary, program the engine prelube duration to 60 seconds.

4. If the engine prelube displays "COMPLETED", the engine prelube duration is reached. Reset the system and troubleshoot any active diagnostic code.

5. Turn the "Start/Run/Stop Switch" to the "STOP" position.

Expected Result:

The parameter for the engine prelube pressure switch should display "ON". The parameter for the start/run/stop switch should display "ON".

Results:

• OK - The parameter for the engine prelube pressure switch does display "ON". The parameter for the start/run/stop switch does display "ON". Proceed to test step 6.

• Not OK - The parameter for the engine prelube pressure switch does not display "ON". The parameter for the start/run/stop switch does not display "ON".

  Repair: There is a problem in the wiring from the "Start/Run/Stop Switch". Perform the diagnostic functional test Troubleshooting, ""Start/Run/Stop Switch"".

  STOP

Test Step 6. Check the Voltage to the Secondary Prelube Relay.

1. Connect a voltmeter between terminal 4 of the secondary prelube relay and engine ground.

2. Access the override on the Cat ET.

3. Turn the override for the engine prelube to "ON".

4. Monitor the voltage on the voltmeter.

5. Deactivate the override for the engine prelube.

Expected Result:

The voltage should measure 24 ± 3 VDC.

Results:

• OK - The voltage measures 24 ± 3 VDC. Proceed to test step 7.

• Not OK - The voltage does not measure 24 ± 3 VDC. Proceed to test step 9.

Test Step 7. Check the Voltage from the Secondary Prelube Relay.

1. Connect a voltmeter between terminal 2 of the secondary prelube relay and engine ground.

2. Access the override on the Cat ET.

3. Turn the override for the engine prelube to "ON".

4. Monitor the voltage on the voltmeter.

5. Deactivate the override for the engine prelube.

Expected Result:

The voltage should measure 24 ± 3 VDC.

Results:

• OK - The voltage measures 24 ± 3 VDC. Proceed to test step 8.

• Not OK - The voltage does not measure 24 ± 3 VDC.

  Repair: Disconnect the wire on terminal 3 of the secondary prelube relay. Check this wire for continuity to engine ground. If the wire is okay, replace the secondary prelube relay. Verify that the problem is no longer present.

  STOP

Test Step 8. Check the Voltage to the Prelubrication Motor.

1. Connect a voltmeter between the wire from the secondary prelube relay at the prelubrication motor and engine ground.

2. Access the override on the Cat ET.

3. Turn the override for the engine prelube to "ON".

4. Monitor the voltage on the voltmeter.

5. Deactivate the override for the engine prelube.

Expected Result:

The voltage should measure 24 ± 3 VDC.

Results:

• OK - The voltage measures 24 ± 3 VDC. The prelubrication motor does not start.

  Repair: Check the connections at the prelubrication motor. If the connections are okay, replace the prelubrication motor. Verify that the problem is no longer present.

  STOP

• Not OK - The voltage does not measure 24 ± 3 VDC.

  Repair: There is a problem in the wiring and/or connectors between the secondary prelube relay and the prelubrication motor. Repair the connectors or wiring and/or replace the connectors or wiring.

  STOP

Test Step 9. Check the Voltage to the Main Prelube Relay.

1. Connect a voltage test lamp between terminal 86 of the main prelube relay and engine ground.

2. Access the override on the Cat ET.

3. Turn the override for the engine prelube to "ON".

4. Monitor the voltage test lamp.

5. Deactivate the override for the engine prelube.

Expected Result:

The voltage test lamp should illuminate.

Results:

• OK - The voltage test lamp illuminated. Proceed to test step 10.

• Not OK - The voltage test lamp did not illuminate. Proceed to test step 12.

Test Step 10. Check the Voltage from the Main Prelube Relay.

1. Connect a voltmeter between terminal 30 of the main prelube relay and engine ground.

2. Access the override on the Cat ET.

3. Turn the override for the engine prelube to "ON".

4. Monitor the voltage on the voltmeter.

5. Deactivate the override for the engine prelube.

Expected Result:

The voltage should measure 24 ± 3 VDC.

Results:

• OK - The voltage measures 24 ± 3 VDC.

  Repair: The wire and/or connectors between terminal 30 of the main prelube relay and terminal 4 of the secondary prelube relay is the problem. Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the problem is no longer present.

  STOP

• Not OK - The voltage does not measure 24 ± 3 VDC. Proceed to test step 11.

Test Step 11. Check the Return Wire from the Main Prelube Relay to the ECM.

1. Turn the engine control to the OFF position.

2. Disconnect ECM connector J2/P2.

3. Remove the wire on terminal 85 of the main prelube relay. Connect a jumper wire from engine ground to the wire that was removed from terminal 85.

4. Measure the resistance between P2-35 and engine ground.

5. Reconnect all wires and connectors.

Expected Result:

The resistance should measure less than 10 Ohms.

Results:

• OK - The resistance measures less than 10 Ohms.

  Repair: Verify that 24 ± 3 VDC is present on terminal 87 of the main prelube relay. If voltage is present on terminal 87 of the main prelube relay, replace the main prelube relay. If voltage is not present on terminal 87 of the main prelube relay, repair the wire and/or connectors between terminal 87 of the main prelube relay and the + Battery terminal. Verify that the problem is no longer present.

  STOP

• Not OK - The resistance measures more than 10 Ohms.

  Repair: The wire and/or connectors between terminal 85 of the main prelube relay and the ECM needs repair. Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the problem is no longer present.

  STOP

Test Step 12. Check the Voltage from the ECM to the Main Prelube Relay.

1. Turn the engine control to the OFF position.

2. Disconnect ECM connector J2/P2.

3. Remove socket P2-35 and socket P2-29 from ECM connector P2. Install wire jumpers into the sockets for P2-35 and P2-29.

4. Connect a voltage test lamp between the wire jumpers that are in P2-35 and P2-29.

5. Turn the engine control to the ON position.

6. Access the override on the Cat ET.

7. Turn the override for the engine prelube to "ON".

8. Monitor the voltage test lamp.

9. Deactivate the override for the engine prelube.

10. Remove the wire jumpers. Replace all wires and connectors.

Expected Result:

The voltage test lamp should illuminate.

Results:

• OK - The voltage test lamp illuminated.

  Repair: The wire and/or connectors between the ECM and the main prelube relay need repair. Repair the connectors or wiring and/or replace the connectors or wiring. Verify that the problem is no longer present.

  STOP

• Not OK - The voltage test lamp did not illuminate.

  Repair: The ECM is not operating correctly. Replace the ECM. Refer to the diagnostic procedure Troubleshooting, "Replacing the ECM".

  STOP