Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. Apply the Brake Pedal.
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 (L54) RIGHT STOP LAMP DRIVER CIRCUIT FOR A SHORT TO VOLTAGE
NOTE:
Make sure the brake pedal is not applied while performing this step.
1. Turn the ignition off.
2. Disconnect the Right Tail Lamp Assembly harness connector.
3. Turn the ignition on.
4. Measure the voltage between ground and the (L54) Right Stop Lamp Driver circuit at the Right Tail Lamp Assembly harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (L54) Right Stop Lamp Driver circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (L54) RIGHT STOP LAMP DRIVER CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the BCM C5/E harness connector.
3. Measure the resistance of the (L54) Right Stop Lamp Driver circuit between the Right Tail Lamp Assembly harness connector and the BCM C5/E harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the open in the (L54) Right Stop Lamp Driver circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (Z922) GROUND CIRCUIT FOR AN OPEN
1. Check for continuity between ground and the (Z922) Ground circuit at the Right Tail Lamp Assembly harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the open in the (Z922) Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE BCM FOR CORRECT OPERATION
1. Turn the ignition off.
2. Reconnect the BCM C5/E harness connector.
3. Turn the ignition on.
4. Apply the Brake Pedal.
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
5. Connect a 12-volt test light between the (L54) Right Stop Lamp Driver circuit and the (Z922) Ground circuit at the Right Tail Lamp Assembly harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Replace the Right Stop Lamp Bulb in accordance with the Service Information. Refer to LAMP, TAIL STOP TURN, REMOVAL .
  - 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 .