938G Wheel Loader, 938G Series II Wheel Loader, IT38G Integrated Toolcarrier and IT38G Series II Integrated Toolcarrier Traction Control System MID 028 - CID 0263 - FMI 01 Caterpillar

Conditions Which Generate This Code:

Note: This procedure can cause new diagnostic codes to be recorded. Ignore these newly created diagnostic codes. Complete this procedure and then clear the diagnostic codes that were created during this procedure.

This failure is recorded when the ECM for the traction control reads the voltage of the sensor supply circuit and the voltage is below normal. The circuit may be shorted to ground.

Test Step 1. CHECK THE VOLTAGE AT THE ELECTRONIC CONTROL MODULE.

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

2. At the machine harness connectors J1 and J2 of the ECM for the traction control, measure the voltage between contact J2-9 (wire 709-OR) and contact J1-2 (wire A219-BK). Use the 7X-1710 Cable probes to measure the voltage. Do NOT disconnect the machine harness from the ECM for the traction control.

Expected Result:

The voltage is 10.0 ± 0.6 DCV.

Results:

• OK - The voltage is 10.0 ± 0.6 DCV. The sensor supply voltage is correct. Verify that the diagnostic code is still active. If the diagnostic code is still active the ECM for the traction control has failed.

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

  Stop.

• NOT OK - The voltage is less than 10.0 ± 0.6 DCV. The sensor supply voltage is NOT correct. Proceed to test step 2.

Test Step 2. CHECK FOR A SHORT TO GROUND.

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

2. Disconnect the machine harness connector J2 from the ECM for the traction control.

3. At the machine harness connector J2 of the ECM for the traction control, measure the resistance between contact J2-9 (wire 709-OR) and frame ground.

Expected Result:

The resistance is greater than 5000 ohms.

Results:

• OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. The ECM for the traction control has failed.

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

  Stop.

• NOT OK - The resistance is less than 5 ohms. The machine harness or a sensor has failed. Proceed to test step 3.

Test Step 3. DISCONNECT THE SENSORS.

1. One at a time disconnect any sensor that uses the +10 volt sensor supply from the machine harness.

   Note: Only disconnect sensors that are associated with this diagnostic code.

2. After you disconnect each sensor, measure the resistance between connector contact J2-9 (709-OR) and frame ground.

Expected Result:

The resistance is greater than 5000 ohms.

Results:

• OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. The sensor that has just been disconnected has failed.

  Repair: Replace the sensor that was just disconnected.

  Stop.

• NOT OK - The resistance is less than 5000 ohms. If the resistance is less than 5000 ohms after all of the sensors have been disconnected from the machine harness. The machine harness is shorted to ground.

  Repair: Repair the machine harness or replace the machine harness.

  Stop.