*NO RESPONSE FROM FDCM (FINAL DRIVE CONTROL MODULE)
For a complete wiring diagram Refer to Section 8W.
| Possible Causes |
| (A926) (A909) (A927) FUSED B(+) CIRCUIT OPEN OR SHORTED |
| (Z901) (Z902) (Z913) GROUND CIRCUIT OPEN |
| (F921) FUSED RUN RELAY OUTPUT CIRCUIT OPEN OR SHORTED |
| (D65) CAN C BUS (+) CIRCUIT OPEN |
| (D64) CAN C BUS (-) CIRCUIT OPEN |
| FINAL DRIVE CONTROL MODULE |
Diagnostic Test
1. TEST FOR INTERMITTENT CONDITIONTurn the ignition on.
NOTE: Ensure the IOD fuse is installed and battery voltage is between 10.0 and 16.0 volts.
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 FCM 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 diagram/schematic as a guide, inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals.
2. FUSED B(+) CIRCUIT OPEN OR SHORTED
Turn the ignition off.
Disconnect the Final Drive Control Module harness connectors.
Using a 12-volt test light connected to ground, check each Fused B(+) circuit.
Does the test light illuminate brightly for each circuit?
Yes
- Go To 3
No
- Repair the Fused B(+) circuit for an open or short.
- Perform the FDCM VERIFICATION TEST.
3. GROUND CIRCUIT OPEN
Using a 12-volt test light connected to 12-volts, check each Ground circuit.
Does the test light illuminate brightly for each circuit?
Yes
- Go To 4
No
- Repair the ground circuit for an open.
- Perform the FDCM VERIFICATION TEST.
4. (F921) FUSED RUN RELAY OUTPUT CIRCUIT OPEN OR SHORTED
Turn the ignition on.
Using a 12-volt test light connected to ground, check the (F921) Fused Run Relay Output circuit.
Does the test light illuminate brightly?
Yes
- Go To 5
No
- Repair the (F921) Fused Run Relay Output circuit for an open or short.
- Perform the FDCM VERIFICATION TEST.
5. (D65) CAN C BUS (+) CIRCUIT OPEN
Turn the ignition off.
Disconnect the FCM C1 harness connector.
Measure the resistance of the (D65) CAN C Bus (+) circuit between the FCM connector and the FDCM connector.
Is resistance below 5.0 ohms?
Yes
- Go To 6
No
- Repair the (D65) CAN C Bus (+) circuit for an open.
- Perform the FDCM VERIFICATION TEST.
6. (D64) CAN C BUS (-) CIRCUIT OPEN
Measure the resistance of the (D64) CAN C Bus (-) circuit between the FCM connector and the FDCM connector.
Is resistance below 5.0 ohms?
Yes
- Replace the Final Drive Control Module in accordance with the service information.
- Perform the FDCM VERIFICATION TEST.
No
- Repair the (D64) CAN C Bus (-) circuit for an open.
- Perform the FDCM VERIFICATION TEST.