Diagnostic Test

CHECK FOR ACTIVE DTC
1. With the scan tool, read the active DTCs.
2. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds.
3. With the scan tool, read the active DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go to step 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. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
LEFT TRAILER TOW RELAY
1. Turn the ignition off.
2. Install a substitute relay in place of the original Left Trailer Tow Relay.
3. Cycle the ignition switch from off to on, leaving the ignition on for a minimum of 90 seconds.
4. With the scan tool, read the active FCM DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Replace the FCM in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Replace the original Left Trailer Tow Relay.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .