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 and any DTCs.
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 AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK (Z341) GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Left Tail/Liftgate Lamp Assembly harness connector.
3. Measure the resistance between ground and the (Z341) Ground circuit at the Left Tail/Liftgate Lamp Assembly harness connector.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the open or high resistance on the (Z341) Ground circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE LEFT BACKUP LAMP BCM OUTPUT
1. Turn the ignition on.
2. Apply the Park Brakes.
3. Shift the Gear Selector to the Reverse position.
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
4. Connect a 12-volt test light between the (Z341) Ground circuit and the (L1) Backup Lamp Feed circuit at the Left Tail/Liftgate Lamp Assembly harness connector.
  Does the test light illuminate brightly with the Backup Lamps on?
  
  Yes
  - Replace the Left Tail/Liftgate Lamp Assembly in accordance with the Service Information. Refer to LAMP, TAIL, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
CHECK LEFT (L1) BACKUP LAMP FEED CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the BCM C6/F harness connector.
3. Measure the resistance on the (L1) Backup Lamp Feed circuit between the Left Tail/Liftgate Lamp Assembly harness connector and the BCM C6/F harness connector - terminal 31.
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the open or high resistance on the (L1) Backup Lamp Feed circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
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. Connect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect 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 AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  - Test complete.