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 (L33) LEFT HIGH BEAM DRIVER CIRCUIT FOR A SHORT TO VOLTAGE
NOTE:
Make sure the Headlamps are off when performing this step.
1. Turn the Headlamps off.
2. Turn the ignition off.
3. Disconnect the Left Front Lamp Assembly harness connector.
4. Turn the ignition on.
5. Measure the voltage on the (L33) Left High Beam Driver circuit at the Left Front Lamp Assembly harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (L33) Left High Beam Driver circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE GROUND CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Measure the resistance between ground and the Ground circuit at the Left Front Lamp Assembly harness connector.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the open in the Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
CHECK THE OPERATION OF THE LEFT HIGH BEAM LAMP
1. Turn the ignition on.
2. Turn the High Beams 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 ground and the (L33) Left High Beam Driver circuit at the Left Front Lamp Assembly harness connector.
  Does the test light illuminate brightly?
  
  Yes
  - Replace the Left High Beam Lamp in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (L33) LEFT HIGH BEAM DRIVER CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the BCM C3/C harness connector.
3. Measure the resistance of the (L33) Left High Beam Driver circuit between the Left Front Lamp Assembly harness connector and the BCM C3/C harness connector.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the open in the (L33) Left High Beam Driver circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 6
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all BCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Reconnect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read BCM DTCs.
  Did the DTC return?
  
  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
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  - Test complete.