Diagnostic Test

CHECK FOR ACTIVE DTCS
1. With the scan tool, record and erase the DTCs.
2. Turn the ignition off, wait 10 seconds, then cycle the ignition on.
3. If possible, operate the liftgate several times.
4. With the scan tool, read the Active DTCs.
  Does the scan tool display; B188C-13-LIFTGATE CONTROL CIRCUIT 1 - CIRCUIT OPEN?
  
  Yes
  - Go To 2
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the appropriate SYSTEM WIRING DIAGRAMS as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and poor pin fit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (Q88) LIFTGATE OPEN DRIVER CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the Power Liftgate Drive Unit harness connector.
3. Measure the resistance of the (Q88) Liftgate Open Driver circuit between the Power Liftgate Drive Unit and the Power Liftgate Control Module C1 connector.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (Q89) LIFTGATE CLOSE DRIVER CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the Power Liftgate Drive Unit harness connector.
3. Measure the resistance of the (Q89) Liftgate Close Driver circuit between the Power Liftgate Drive Unit and the Power Liftgate Module C1 connector.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
LOAD TEST THE (Q89) LIFTGATE CLOSE DRIVER CIRCUIT TO CHECK FOR HIGH RESISTANCE
1. The ignition must be off.
2. Disconnect the Power Liftgate Drive Unit C1 harness connector.
3. Connect one end of the 12-volt test light to the positive side of the Battery.
4. Use an approved back probe tool and a fused jumper wire, connect the negative end of the 12-volt test light to the (Q89) Liftgate Close Driver circuit.
  The bulb on the load test tool should be illuminated and bright if there is no resistance in the circuit. Does the test light illuminate brightly when the switch is pressed in both directions?
  
  Yes
  - Go To 5
  No
  - Repair the circuit for high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PLDU 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.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
5. Connect all PLDU 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. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Power Liftgate Drive Unit in accordance with the Service Information. Refer to DRIVE UNIT, POWER, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Test complete. Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .