No Response From FDCM (Final Drive Control Module) (Power Wagon Only)

NO RESPONSE FROM FDCM (FINAL DRIVE CONTROL MODULE) (POWER WAGON ONLY)












1. TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.

NOTE: Make sure the IOD fuse is installed and battery voltage is between 10.0 and 16.0 volts.

2. With the scan tool, select ECU view.

NOTE: A red "X" will be next to the module that is not communicating, indicating that the module is not active on the Bus network. A green check indicates that the module is active on the Bus network.

NOTE: Check the Totally Integrated Power Module (TIPM) for any active CAN C hardware DTCs, perform DTC before proceeding.

Does the scan tool display a red "X" next to the module?

Yes

- Go To 2

No

- The no response condition is not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.

2. (A959) FUSED B(+) CIRCUIT OPEN OR SHORTED




1. Turn the ignition off.
2. Disconnect the Final Drive Control Module harness connector.
3. Using a 12-volt test light connected to ground, check the (A959) Fused B(+) circuit.

Does the test light illuminate brightly?

Yes

- Go To 3

No

- Repair the open or short (A959) Fused B(+) circuit.
- Perform the FDCM VERIFICATION TEST. FDCM Verification Test.

3. (Z904) GROUND CIRCUIT OPEN




1. Using a 12-volt test light connected to 12-volts, check the (Z904) Ground circuit.

Does the test light illuminate brightly for each circuit?

Yes

- Go To 4

No

- Repair the open in the (Z904) Ground circuit.
- Perform the FDCM VERIFICATION TEST. FDCM Verification Test.

4. (F946) FUSED IGNITION SWITCH OUTPUT (RUN-START) CIRCUIT OPEN OR SHORTED




1. Turn the ignition on.
2. Using a 12-volt test light connected to ground, check the (F946) Fused Ignition Switch Output (Run-Start) circuit.

Does the test light illuminate brightly?

Yes

- Go To 5

No

- Repair the open or short in the (F946) Fused Ignition Switch Output (Run-Start) circuit.
- Perform the FDCM VERIFICATION TEST. FDCM Verification Test.

5. (D52) CAN C BUS (+) CIRCUIT OPEN




1. Turn the ignition off.
2. Disconnect the TIPM C7 harness connector.
3. Measure the resistance of the (D52) CAN C Bus (+) circuit between the TIPM C7 harness connector and the FDCM harness connector.

Is resistance below 5.0 Ohms?

Yes

- Go To 6

No

- Repair the open in the (D52) CAN C Bus (+) circuit.
- Perform the FDCM VERIFICATION TEST. FDCM Verification Test.

6. (D51) CAN C BUS (-) CIRCUIT OPEN




1. Measure the resistance of the (D51) CAN C Bus (-) circuit between the TIPM C7 harness connector and the FDCM harness connector.

Is resistance below 5.0 Ohms?

Yes

- Replace the FDCM.
- Perform the FDCM VERIFICATION TEST. FDCM Verification Test.

No

- Repair the open in the (D51) CAN C Bus (-) circuit.
- Perform the FDCM VERIFICATION TEST. FDCM Verification Test.