No Response From FCM (Front Control Module)

NO RESPONSE FROM FCM (FRONT CONTROL MODULE)





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.






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

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

NOTE: Ensure the scan tool is updated to the latest software.

NOTE: If the scan tool displays any error messages involving the CAN C Diagnostic circuits, diagnose and repair the error message before proceeding.

NOTE: A loss of communication with the FCM can cause the ECU View button on the scan tool to be inoperative (not highlighted).

2. With the scan tool, attempt to select ECU view.

Can the scan tool communicate with the FCM?

Yes

- 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.

No

- Go To 2

2. (A918) FUSED B(+) CIRCUIT OPEN AT DLC




1. Disconnect the scan tool from the DLC.

NOTE: Check IPM fuses before continuing.

2. Using a 12-volt test light connected to ground, check the (A918) Fused B(+) circuit.

Does the test light illuminate brightly?

Yes

- Go To 3

No

- Repair the (A918) Fused B(+) circuit for an open or short.
- Perform the BODY VERIFICATION TEST. Body Verification Test

3. (Z11) GROUND CIRCUIT OPEN AT DLC




1. Using a 12-volt test light connected to 12-volts, check the (Z11) ground circuit.

Does the test light illuminate brightly?

Yes

- Go To 4

No

- Repair the (Z11) ground circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test

4. GROUND CIRCUITS OPEN AT FCM C1 AND C2 CONNECTORS




1. Disconnect the FCM C1 and C2 harness connectors.
2. 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 5

No

- Repair the ground circuit for an open. Inspect the connector for damage.
- Perform the BODY VERIFICATION TEST. Body Verification Test

5. GROUND CIRCUITS OPEN AT FCM IPM CONNECTOR




1. Remove the FCM from the IPM.
2. 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 6

No

- Repair the ground circuit for an open. Inspect the connector for damage.
- Perform the BODY VERIFICATION TEST. Body Verification Test

6. FUSED B(+) CIRCUITS OPEN AT FCM IPM CONNECTOR





NOTE: Check IPM fuses before continuing.

1. Using a 12-volt test light connected to ground, check each Fused B(+) circuit.

Does the test light illuminate brightly for each circuit?

Yes

- Replace and program the Front Control Module.
- Perform the BODY VERIFICATION TEST. Body Verification Test

No

- Repair the Fused B(+) circuit for an open. Inspect the connector for damage. If ok, replace the PDC portion of the IPM.
- Perform the BODY VERIFICATION TEST. Body Verification Test