950G Wheel Loader, 962G Wheel Loader and IT62G Integrated Toolcarrier Power Train Caterpillar

Illustration 1	g00435878
Schematic for the Rotary Switch (Transmission Auto/Manual)

The two-position transmission auto/manual switch has two inputs to the power train electronic control module (ECM). These inputs are normally open (N/O) and normally closed (N/C). During normal operation, one of the inputs is open and the other input is grounded. If both inputs are the same, the power train ECM detects a fault. Also, this fault is detected when both inputs are either open or shorted to the +battery. Before performing this procedure refer to table 2 in order to determine the connector and the contact that corresponds to the faulty circuit.

Note: Ensure that the desired fault CID 0368 FMI 03 is active.

Note: The following procedure can create other faults that the power train ECM detects. Ignore these created faults and clear the created faults when CID 0368 FMI 03 is corrected.

1. Check for an open circuit.

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

   2. Disconnect the machine harness from the power train ECM.

   3. At the machine harness connector for the power train ECM, check the continuity to ground of the N/C contact and the N/O contact with the transmission auto/manual switch activated and not activated. Refer to table 2 for the correct continuity combinations.

      Expected Result: The continuity check does not agree with the information found in table 2.

      Results:

      • YES - The continuity check does NOT agree with table 2. The harness or the transmission auto/manual switch is faulty. Proceed to Step 2.

      • NO - The continuity check agrees with table 2. Proceed to Step 3.

2. Check the transmission auto/manual switch.

   1. Disconnect the machine harness from the transmission auto/manual switch.

   2. Check the continuity to ground of the N/C contact and the N/O contact with the transmission auto/manual switch activated and not activated. Refer to table 2 for the correct continuity combinations.

      Expected Result: The continuity check does not agree with the table 2.

      Results:

      • YES - The continuity check does not agree with table 2. The transmission auto/manual switch is faulty. Repair the switch or replace the switch.

      • NO - Continuity check agrees with table 2. Repair the machine harness or replace the machine harness.

3. Check for a short to the +battery.

   1. At the machine harness connector for the power train ECM, check the continuity from each of the switch contact wires to the contacts J1-1, J1-6, J1-40 and J2-12.

      Expected Result: Continuity exists between one of the sources of the battery voltage and the switch circuit.

      Results:

      • YES - Continuity exists between one of the sources of battery voltage. The machine harness is faulty. Repair the machine harness or replace the machine harness.

      • NO - Continuity does not exist between one of the sources of battery voltage and the switch circuit. The machine harness is correct. It is unlikely that an power train ECM is faulty. Exit this procedure and perform CID 0368 FMI 03. If the cause is not found, replace the power train ECM. Refer to Testing and Adjusting, "Electronic Control Module (Power Train) - Replace" for more information on replacing the power train ECM.