24H Motor Grader Transmission Electronic Control System And Hydraulic Calibrations Caterpillar

Illustration 1	g00528752
Schematic For The Shift Lever

Service Notes: Before troubleshooting one of these faults, move the shift lever through all positions. Ensure that the fault that is being analyzed is on hold.

1. CHECK THE GROUND CIRCUIT OF THE SHIFT LEVER .

   1. Turn the disconnect switch to OFF position.

   2. Disconnect the connector (24 contact) of the shift lever.

   3. At the machine harness connector for the shift lever, check for continuity from ground to contact 2.

      Expected Result:There is continuity.

      Results:

      • YES - There is continuity. The ground circuit of the shift lever is correct. Go to Step 2.

      • NO - There is NO continuity. The ground circuit of the shift lever in the harness has a fault. Repair the machine harness or replace the harness.

2. CHECK THE SHIFT LEVER.

   1. See Testing and Adjusting, "Transmission Control (Shift Lever) - Test". Perform the test.

      Expected Result: The shift lever is correct.

      Results:

      • YES - Shift lever is correct. There is a problem with the harness. Go to Step 3.

      • NO - Shift lever NOT correct. There is a fault in the shift lever. Replace the shift lever.

3. CHECK THE HARNESS FROM THE SHIFT LEVER TO THE ECM. Use the Electrical System Schematic as a reference, and check for shorts and check for continuity of the harness circuits between the shift lever and the ECM.

   Expected Result: The harness is NOT correct.

   Results:

   • YES - Harness is NOT correct. Repair the machine harness or replace the machine harness.

   • NO - Harness is correct. Check all connector contacts. Check the ECM for shift lever fault codes. If a fault is still present, replace the ECM. See Testing And Adjusting, "Electronic Control Module (ECM) - Replace".