Front Control Module (FCM)

B211A-IGNITION RUN/ACC/SPAD CONTROL CIRCUIT LOW





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

Theory of Operation

The family of B2100 Diagnostic Trouble codes (DTCs) typically describes ignition performance related faults. These are often caused by a contradiction of switch status information. For example, if an Electronic Control Unit (ECUA) receives a bussed message indicating ignition switch position but the state of a hardwired ignition circuit indicates another switch position a B2100 series DTC would likely result.

These DTCs can be caused by a number of conditions including:

- loose connections
- missing or blown fuses
- faulty component
- vehicle no start or long crank time

Verify the proper operation of the starting system and verify that this DTC is active before proceeding with the diagnostic test.

- When Monitored:
With the ignition on.

- Set Condition:
The Front Control Module (FCM) will set this DTC within 500ms if the (W12) Rear Wiper Relay Control circuit is shorted to ground.





1. CHECK FOR ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
1. Turn the ignition on.
2. Using the scan tool, read the active DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out or corroded terminals.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. (W12) REAR WIPER RELAY CONTROL CIRCUIT SHORTED TO GROUND




1. Turn the ignition off.
2. Disconnect the Junction Block C1 harness connector.
3. Measure the resistance between ground and the (W12) Rear Wiper Relay Control circuit at the Junction Block C1 harness connector.

Is the resistance below 100.0 Ohms?

Yes

- Go To 3

No

- Replace the Junction Block.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. (W12) REAR WIPER RELAY CONTROL CIRCUIT SHORTED TO GROUND




1. Disconnect the IPM C2 harness connector.
2. Measure the resistance between ground and the (W12) Rear Wiper Relay Control circuit at the Junction Block C1 harness connector.

Is the resistance below 100.0 Ohms?

Yes

- Repair the (W12) Rear Wiper Relay Control circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. INTEGRATED POWER MODULE (IPM) / FRONT CONTROL MODULE (FCM)




1. Reconnect the IPM C2 harness connector.
2. Remove the FCM from the IPM.
3. Measure the resistance between ground and the (W12) Rear Wiper Relay Control circuit at the Junction Block C1 harness connector.

Is the resistance below 100.0 Ohms?

Yes

- Replace the IPM.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the FCM.
- Perform the BODY VERIFICATION TEST. Body Verification Test.