Diagnostic Test

INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, clear all FCM DTCs.
3. Turn the Left Turn Signal on.
4. With the scan tool read the DTCs.
  Does the scan tool read: B1643-REAR LEFT TURN CONTROL CIRCUIT LOW?
  
  Yes
  - Go to step 2
  No
  - The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
(L63) LEFT TURN SIGNAL CONTROL CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Disconnect the 49 way FCM/IPM harness connector.
3. Disconnect the Left Turn Stop Tail Lamp harness connector.
4. Measure the resistance between ground and the (L63) Rear Left Turn Signal Control circuit at the Left Turn Stop Tail Lamp harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Repair the (L63) Rear Left Turn Signal Control circuit for a short to ground.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Go to step 3
FRONT CONTROL MODULE (FCM)
1. Turn the ignition off.
2. Disconnect the IPM C2 harness connector.
3. Measure the resistance between ground and the (L63) Left Turn Signal Control circuit in the IPM.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Replace the Integrated Power Module (IPM) in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Replace the Front Control Module (FCM) in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .