CB-434D, CB-534D, CB-534D Series XW and CB-564D Paving Compactors Caterpillar

One of the following conditions may exist:

• A solenoid valve has failed.

• An offset switch has failed.

• There is a short in a circuit.

• The ECM has failed.

Illustration 1	g00950951

Test Step 1. CHECK THE OFFSET SYSTEM

1. Turn the key start switch and the disconnect switch to the OFF position.

2. Disconnect the connectors for the offset solenoids.

3. Turn the key start switch and the disconnect switch to the ON position.

4. Measure the voltage at the left offset solenoid from contact 1 to contact 2.

5. Measure the voltage at the right offset solenoid from contact 1 to contact 2.

Expected Result:

No voltage is present.

Results:

• OK - No voltage is present. Proceed to Test Step 5.

• NOT OK - Voltage is present on at least one of the readings. Proceed to Test Step 2.

Test Step 2. CHECK THE INPUT SIGNAL AT THE ECM

1. At the back of the harness connector for the ECM, insert the 7X-1710 Multimeter Probes along contact 22 and contact 2 (wires H751-OR and 200-BK).

2. Turn the key start switch and the disconnect switch to the ON position.

3. Measure the voltage from contact 22 to contact 2 of the machine harness on the ECM.

4. At the back of the harness connector for the ECM, remove the 7X-1710 Multimeter Probe from contact 22 and insert the Multimeter Probe along contact 23 (wire H750-BR).

5. Measure the voltage from contact 23 to contact 2 of the machine harness on the ECM.

Expected Result:

No voltage is present.

Results:

• OK - No voltage is present. Proceed to Test Step 4.

• NOT OK - Voltage is present on at least one of the readings. Proceed to Test Step 3.

Test Step 3. CHECK THE OUTPUT VOLTAGE AT THE PROPEL LEVER

1. At the back of the harness connector for the propel lever, remove wire H751-OR from contact 1.

2. At the back of the harness connector for the propel lever, remove wire H750-BR from contact 3.

3. Turn the key start switch and the disconnect switch to the ON position.

4. Measure the voltage from contact 1 to frame ground on the propel lever.

5. Measure the voltage from contact 3 to frame ground on the propel lever.

Expected Result:

No voltage is present.

Results:

• OK - No voltage is present.

  Repair: The wiring harness has failed. Repair the wiring harness or replace the wiring harness.

  Stop.

• NOT OK - Voltage is present on at least one of the readings.

  Repair: The switch in the propel lever has failed. Replace the propel lever.

  Stop.

Test Step 4. CHECK THE OUTPUT VOLTAGE AT THE ECM

1. Turn the key start switch and the disconnect switch to the OFF position.

2. At the back of the harness connector for the ECM, remove wire C929-WH from contact 40.

3. At the back of the harness connector for the ECM, remove wire C928-GY from contact 30.

4. Turn the key start switch and the disconnect switch to the ON position.

5. Measure the voltage from contact 40 to contact 2 on the ECM.

6. Measure the voltage from contact 30 to contact 2 on the ECM.

Expected Result:

No voltage is present.

Results:

• OK - No voltage is present.

  Repair: The wiring harness has failed. Repair the wiring harness or replace the wiring harness.

  Stop.

• NOT OK - Voltage is present on at least one of the readings.

  Repair: It is unlikely that the ECM has failed. Exit this procedure and perform the procedures again. If the cause of the failure is not found, replace the ECM. See Troubleshooting, "Electronic Control Module (ECM) - Replace".

  Stop.

Test Step 5. CHECK THE VOLTAGE AT THE SOLENOIDS

1. Turn the key start switch and the disconnect switch to the ON position.

2. Actuate the offset switch to the left position and check the voltage at the left offset solenoid from contact 1 to contact 2.

3. Actuate the offset switch to the right position and check the voltage at the right offset solenoid from contact 1 to contact 2.

Expected Result:

The voltages are approximately 12 volts.

Results:

• OK - The voltages are approximately 12 volts.

  Repair: The problem is not electrical. Refer to Troubleshooting, "Steering System" for further details.

  Stop.

• NOT OK - The voltage is less than 12 volts on one of the readings or both of the readings.

  Repair: Refer to Troubleshooting, "Drum Does Not Offset" for further details.

  Stop.