966G Wheel Loader and 972G Wheel Loader Power Train Caterpillar

CID 0622 FMI 04 Push Button Switch (Upshift) Voltage Below Normal - Test

Usage:

972G 1EW

Show/hide table




Illustration 1	g00506568
Transmission Upshift Switch Schematic

The transmission upshift 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. CID 0622 FMI 04 service code is recorded when both the N/O and N/C inputs of the transmission upshift switch are grounded.

Note: Ensure that the desired fault CID 0622 FMI 04 is active.

Note: The following procedure can create other faults that the power train ECM will detect. Ignore these created faults and clear the faults when CID 0622 FMI 04 is corrected.

Show/hide table

Table 1
Upshift Switch Status
Switch Position	F785-WH Circuit (N/O) J1-23	F783-GN Circuit (N/C) J1-19
Sw. Depressed	Closed	Open
Sw. Released	Open	Closed

Check for an open circuit.
1. Ensure that the fault is active.
1. Observe the ON/OFF status of the fault.
1. Disconnect the connector of the transmission upshift switch from the machine harness.
  Expected Result: The active fault changes from "04" to "03".
  Results:
  - YES - The transmission upshift switch or the switch harness has failed. Repeat Step 1 to verify the transmission upshift switch failure. Repair or replace the switch and or the switch harness.
  - NO - The fault present indicator remains ON. The transmission upshift switch is not the cause of this fault. Proceed to Step 2.

Check the harness circuit.
This test checks the continuity of the entire harness circuit that may be faulty. The transmission upshift switch that was previously checked in Step 1 is included in this test.
1. Turn the key start switch and the disconnect switch to the OFF position.
1. Connect the transmission upshift switch of Step 1 to the machine harness.
1. Disconnect the machine harness connector J1 from the power train ECM.
1. 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 upshift switch activated and not activated. Refer to table 1 for the correct switch status.
  Expected Result: The continuity check does not agree with table 1.
  Results:
  - YES - The continuity check does NOT agree with table 1. The harness circuit is faulty. There is a short to ground in the machine harness between the power train ECM and the transmission upshift switch. Repair the machine harness or replace the machine harness. STOP.
  - NO - The continuity check agrees with table 1. The harness circuit is correct. It is unlikely that the power train ECM is faulty. Exit this procedure and perform CID 0622 FMI 04 again. 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. STOP.