Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. Turn the Park Lamps on.
3. With the scan tool, read the Body Control Module (BCM) DTCs and record on the repair order.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - 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. If no problems are found, test complete.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (L78) RIGHT FRONT PARK LAMP DRIVER CIRCUIT FOR A SHORT TO VOLTAGE
NOTE:
Make sure the Park Lamps are off when performing this step.
1. Turn the Park Lamps off.
2. Turn the ignition off.
3. Disconnect the Right Front Lamp Assembly harness connector.
4. Disconnect the Right Sidemarker Lamp Assembly harness connector.
5. Turn the ignition on.
6. Measure the voltage on the (L78) Right Front Park Lamp Driver circuit at the Right Front Lamp Assembly harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (L78) Right Front Park Lamp Driver circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (Z902) GROUND CIRCUITS FOR AN OPEN
1. Turn the ignition off.
2. Measure the resistance between ground and the (Z902) Ground circuit at the Right Front Lamp Assembly harness connector.
3. Measure the resistance between ground and the (Z902) Ground circuit at the Right Sidemarker Lamp Assembly harness connector.
  Is the resistance above 3.0 Ohms for any of the connections?
  
  Yes
  - Repair the open in the (Z902) Ground circuit(s).
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
CHECK THE BCM OUTPUT FOR CORRECT OPERATION
1. Turn the ignition on.
2. Turn the Park Lamps on.
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
3. Connect a 12-volt test light between the (L78) Right Front Park Lamp Driver circuit and the (Z902) Ground circuit at the Right Front Lamp Assembly harness connector.
4. Connect a 12-volt test light between the (L78) Right Front Park Lamp Driver circuit and the (Z902) Ground circuit at the Right Sidemarker Lamp Assembly harness connector.
  Does the test light illuminate brightly for both connections?
  
  Yes
  - Replace the Right Front Sidemarker Lamp or Right Front Park Lamp in accordance with the Service Information. Refer to UNIT, FRONT LAMP, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (L78) RIGHT FRONT PARK LAMP DRIVER CIRCUIT FOR AN OPEN
1. Turn the Park Lamps off.
2. Turn the ignition off.
3. Disconnect the BCM C4/D harness connector.
4. Measure the resistance of the (L78) Right Front Park Lamp Driver circuit between the Right Front Lamp Assembly harness connector and the BCM C4/D harness connector.
5. Measure the resistance of the (L78) Right Front Park Lamp Driver circuit between the Right Sidemarker Lamp Assembly harness connector and the BCM C4/D harness connector.
  Is the resistance above 3.0 Ohms for any of the connections?
  
  Yes
  - Repair the open in the (L78) Right Front Park Lamp Driver circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - 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 .