Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read Body Control Module (BCM) DTCs and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase DTCs.
4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. With the scan tool, read BCM DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR INTERMITTENT CONDITIONS procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE (L107) MAIN LIGHTING SWITCH CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Headlamp Switch harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (L107) Main Lighting Switch circuit at the Headlamp Switch harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (L107) Main Lighting Switch circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (L107) MAIN LIGHTING SWITCH CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the BCM C8/H harness connector.
3. Measure the resistance of the (L107) Main Lighting Switch circuit between the Headlamp Switch harness connector and the BCM C8/H harness connector.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the open in the (L107) Main Lighting Switch circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the Headlamp Switch in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .