Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go To 2
  No
  - Test complete. The condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct pin tension.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE PARK LAMP RELAY
1. Turn the Park Lamps off.
2. Turn the ignition off.
3. Remove the Park Lamp Relay and substitute it with a known good relay.
4. Turn the ignition on.
5. Turn the Park Lamps on.
6. With the scan tool, read DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go To 3
  No
  - Replace the Park Lamp Relay.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (L779) PARK LAMP RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS
1. Turn the ignition off.
2. Disconnect the BCM C8 harness connector.
3. Disconnect the Power Distribution Center Auxiliary Assembly C1 harness connector.
4. Measure the resistance between ground and the (L779) Park Lamp Relay Control circuit.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the short to ground in the (L779) Park Lamp Relay Control circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (L779) PARK LAMP RELAY CONTROL CIRCUIT FOR AN OPEN IN THE HARNESS
1. Turn the ignition off.
2. Measure the resistance of the (L779) Park Lamp Relay Control circuit between the Power Distribution Center Auxiliary Assembly C1 harness connector and the BCM C8 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Replace the Body Control Module (BCM) in accordance with the Service Information. Refer to MODULE, BODY CONTROL (BCM), REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Repair the open in the (L779) Park Lamp Relay Control circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .