3500B Series II Marine Engines Prelubrication System Caterpillar

System Operation Description:

The Electronic Control Module (ECM) has the ability to automatically prelube the engine before cranking. This prelubrication may increase the life of certain engine parts. The ECM will prelube the engine, when the Engine Control Switch (ECS) is placed in the START position. The ECM will prelube the engine, when the ECS is placed in the AUTO position and the remote start/run/stop switch is closed. The length of time for the prelube cycle can be programmed by the customer. The prelube cycle will end when the prelube pressure switch closes or if the customer programmed time ends. The engine speed must equal zero rpm before the prelube will begin.

The prelube cycle has the following status codes: "OFF", "ON", "COMPLETED" and "DISABLED".

The "OFF" status is entered when the engine control is first powered up with the ECS in the STOP position.

The "ON" status is entered when the ECM is on with the ECS in the START position.

The "COMPLETED" status is entered when the engine prelube duration is reached or when the engine prelube's pressure switch is activated.

The "DISABLED" status is entered when the engine prelube duration is programmed to 0.

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

• The prelube pressure switch is activated.

• The user defined engine prelube duration has been reached.

• The operator activates the prelube override switch.

When the ECM senses the ECS in the START position, the ECM will activate the output driver for the "PPR1" relay. When the "PPR1" relay energizes, the normally open contacts of the "PPR1" relay close. This allows current to flow to the prelube motor. The prelube motor activates the prelube pump. The prelube pump builds pressure in the engine's lubrication system. When the prelube pressure switch closes as a result of the increased pressure, the ECM input for the prelube pressure switch is taken low. The ECM then knows that the prelube pressure is adequate. The ECM will begin the starting sequence.

Illustration 1	g01193921

Test Step 1. Check for Connector Damage.

1. Turn the circuit breaker for the battery to the OFF position.

2. Turn the ECS to the OFF/RESET position.

3. 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.

4. Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for the correct torque values.

5. Check the ECM connector (allen head screw) for the proper torque of 6 ± 1 N·m (53 ± 9 lb in).

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

Expected Result:

All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion, and of pinch points.

Results:

• OK - The connectors and wiring are OK. Proceed to Test Step 2.

• Not OK - The connectors and/or wiring are not OK.

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

  STOP

Test Step 2. Check the Resistance of the Prelube Pressure Switch at the ECM.

1. Turn the ECS to the OFF/RESET position.

2. Disconnect ECM connector J1/P1.

3. Ensure that the prelube override switch is not activated.

4. Measure the resistance between the prelube pressure switch P1-66 and the digital return P1-5.

5. Reconnect the ECM connector P1.

Expected Result:

The resistance is greater than 20000 Ohms.

Note: If the engine has been running, the residual oil pressure may be high enough to activate the prelube pressure switch. If the residual oil pressure is high, the resistance would be less than 5 Ohms.

Results:

• OK - The resistance is greater than 20000 Ohms. The prelube pressure switch is not active. Proceed to Test Step 4.

• Not OK - The resistance is less than 20000 Ohms. The 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 3.

Test Step 3. Measure the Resistance of the Prelube Pressure Switch at the Prelube Pressure Switch.

1. Turn the ECS to the OFF/RESET position.

2. Disconnect the wires from the terminals of the prelube pressure switch.

3. Measure the resistance between the terminals of the prelube pressure switch.

Expected Result:

The resistance is greater than 20000 Ohms.

Results:

• OK - The resistance is greater than 20000 Ohms. There is a problem with the wiring between ECM connector J1/P1 and the switch.

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

  STOP

• Not OK - The resistance is less than 20000 Ohms. There is a problem with the prelube pressure switch.

  Repair: Temporarily replace the prelube pressure switch with a new switch. If the problem is no longer present, reinstall the old switch. If the problem returns, replace the switch.

  STOP

Test Step 4. Check the Status of the ECS and the Prelube Pressure Switch on the AVSpare Electronic Technician (ET).

1. Connect Cat ET to the service tool connector.

2. Turn the ECS to the STOP position.

3. Use Cat ET and view the following parameters: Engine Prelube and Ignition Switch.

4. Go to the diagnostic test in the diagnostic section on AVS ET. Activate the override for the engine prelube.

5. View the parameters for the prelube pressure switch and the ignition switch.

6. Disable the override for the engine prelube.

Expected Result:

When the ECS is in the STOP position, the engine prelube displays "OFF" and the ignition switch displays "STOP". When the override for the engine prelube is activated, the engine prelube displays "ON" and the ignition switch displays "STOP".

Results:

• OK - The parameters are correct. Proceed to Test Step 5.

• Not OK - The status of the ignition switch does not display "STOP".

  Repair: Perform the diagnostic functional test Troubleshooting, "Engine Control Switch (ECS)".

  STOP

• Prelube Disabled - The prelube function is disabled. The engine prelube duration is set to zero.

  Repair: The cycle time of the engine prelube must be greater than zero for the prelube function to work.

  STOP

Test Step 5. Check for Output Voltage from the "PPR1" Relay at the Connector P-C1 to the Prelube Motor.

1. Turn the ECS to the OFF/RESET position.

2. Connect one end of the voltmeter to the −Battery terminal.

3. Connect the other end of the voltmeter on wire G705 on pin X at connector P-C1 of the rigid harness.

4. Turn the ECS to the STOP position.

5. Go to the diagnostic test in the diagnostic section on AVS ET. Activate the override for the engine prelube.

6. Monitor the voltage on the voltmeter.

7. Disable the override for the engine prelube.

Expected Result:

The voltage is 24 ± 3 VDC.

Results:

• OK - The voltage is 24 ± 3 VDC. Proceed to Test Step 11.

• Not OK - The voltage is not 24 ± 3 VDC. Proceed to Test Step 6.

Test Step 6. Check for Output Voltage from the ECM at the Connector P-C1 to the "PPR1" Relay.

1. Turn the ECS to the OFF/RESET position.

2. Connect one end of the voltmeter to the −Battery terminal.

3. Connect the other end of the voltmeter on wire F705 on pin c at connector P-C1 of the rigid harness.

4. Turn the ECS to the STOP position.

5. Go to the diagnostic test in the diagnostic section on AVS ET. Activate the override for the engine prelube.

6. Monitor the voltage on the voltmeter.

7. Disable the override for the engine prelube.

Expected Result:

The voltage is 24 ± 3 VDC.

Results:

• OK - The voltage is 24 ± 3 VDC. Proceed to Test Step 7.

• Not OK - The voltage is not 24 ± 3 VDC. Proceed to Test Step 10.

Test Step 7. Check for Output Voltage to the Prelube Motor from the "PPR1" Relay.

1. Turn the ECS to the OFF/RESET position.

2. Connect one end of the voltmeter to the −Battery terminal.

3. Connect the other lead of the voltmeter to wire G705 on terminal 2 of the "PPR1" relay.

4. Turn the ECS to the STOP position.

5. Go to the diagnostic test in the diagnostic section on AVS ET. Activate the override for the engine prelube.

6. Monitor the voltage on the voltmeter.

7. Disable the override for the engine prelube.

Expected Result:

The voltage is 24 ± 3 VDC.

Results:

• OK - The voltage is 24 ± 3 VDC.

  Repair: Repair the wire G705 between terminal 2 of the "PPR1" relay and terminal X at the connector P-C1 of the rigid harness.

  STOP

• Not OK - The voltage is not 24 ± 3 VDC. Proceed to Test Step 8.

Test Step 8. Check for Output Voltage to the "PPR1" Relay from the ECM.

1. Leave one end of the voltmeter on the −Battery terminal.

2. Connect the other lead of the voltmeter to wire F705 on terminal 3 of the "PPR1" relay.

3. Turn the ECS to the STOP position.

4. Go to the diagnostic test in the diagnostic section on AVS ET. Activate the override for the engine prelube.

5. Monitor the voltage on the voltmeter.

6. Disable the override for the engine prelube.

Expected Result:

The voltage is 24 ± 3 VDC.

Results:

• OK - The voltage is 24 ± 3 VDC. Proceed to Test Step 9.

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

  Repair: Repair the wire F705 between terminal 3 of the "PPR1" relay and terminal c at the connector P-C1 of the rigid harness.

  STOP

Test Step 9. Check the Voltage across the Coil of the "PPR1" Relay.

1. Connect one lead of the voltmeter to wire D229 on terminal 4 of the "PPR1" relay.

2. Connect the other lead of the voltmeter to wire F705 on terminal 3 of the "PPR1" relay.

3. Turn the ECS to the STOP position.

4. Go to the diagnostic test in the diagnostic section on AVS ET. Activate the override for the engine prelube.

5. Monitor the voltage on the voltmeter.

6. Disable the override for the engine prelube.

Expected Result:

The voltage is 24 ± 3 VDC.

Results:

• OK - The voltage is 24 ± 3 VDC.

  Repair: Verify that 24 ± 3 VDC is present on terminal 1 of the "PPR1" relay. If voltage is not present on terminal 1 of the "PPR1" relay, check the wire K708 and the circuit breaker for the "Prelube Air S/O" between the "PPR1" relay and the battery.

  If 24 ± 3 VDC is present on terminal 1 of the "PPR1" relay, replace the "PPR1" relay.

  STOP

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

  Repair: There is a problem with the wire D229 between the "PPR1" relay and the circuit breaker for the "primary ECM". Disconnect wire D229 from terminal 4 of the "PPR1" relay. Check wire D229 for continuity to the circuit breaker for the "primary ECM". Repair the wire or replace the wire.

  STOP

Test Step 10. Check the Voltage from the ECM to the "PPR1" Relay.

1. Turn the ECS to the OFF/RESET position.

2. Disconnect ECM connector J2/P2.

3. Remove wire F705 from P2-12 at ECM connector P2. Install a wire jumper into P2-12.

4. Connect a voltmeter between the wire jumper in P2-12 and the −Battery terminal.

5. Turn the ECS to the STOP position.

6. Go to the diagnostic test in the diagnostic section on AVS ET. Activate the override for the engine prelube.

7. Monitor the voltage on the voltmeter.

8. Disable the override for the engine prelube.

9. Turn the ECS to the OFF/RESET position.

10. Remove all jumpers and replace all wires.

Expected Result:

The voltage is 24 ± 3 VDC.

Results:

• OK - The voltage is 24 ± 3 VDC. There is a problem in the wire F705 between the ECM and terminal c at the connector P-C1 of the rigid harness.

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

  STOP

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

  Repair: The problem may be the ECM. Check the electrical power to the ECM. Refer to the diagnostic functional test Troubleshooting, "Electrical Power Supply".

  STOP

Test Step 11. Check the Voltage at the Prelube Motor.

1. Connect one end of the voltmeter to wire G705 at the prelube motor.

2. Connect the other end of the voltmeter to the −Battery terminal.

3. Turn the ECS to the STOP position.

4. Go to the diagnostic test in the diagnostic section on AVS ET. Activate the override for the engine prelube.

5. Monitor the voltage on the voltmeter.

6. Disable the override for the engine prelube.

Expected Result:

The voltage is 24 ± 3 VDC.

Results:

• OK - The voltage is 24 ± 3 VDC. There is a problem in the prelube motor. Proceed to Test Step 12.

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

  Repair: There is a problem with the wire G705 between the connector for the prelube motor and terminal X at the connector P-C1 of the rigid harness. Repair wire G705.

  STOP

Test Step 12. Check the Operation of the Prelube Motor.

1. Turn the ECS to the OFF/RESET position.

2. Connect one side of a suitable piece of 10 AWG wire to the +Battery terminal.

3. For one second, connect the other end of the wire to the +Battery terminal of the prelube motor.

Expected Result:

The prelube motor starts.

Results:

• OK - The prelube motor starts. There is a problem in the wiring harness at the prelube motor.

  Repair: Inspect the connectors at the prelube motor.

  STOP

• Not OK - The prelube motor did not start.

  Repair: Verify that wire H705 has continuity between the prelube motor and the circuit breaker for the "Prelube Air S/O". If wire H705 is OK, replace the prelube motor with a new prelube motor. Verify that the problem is no longer present.

  STOP