Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, create a Vehicle Scan Report and attach it to the repair order.
3. Erase DTCs.
4. Turn the ignition off, wait 10 seconds, then turn the ignition on.
5. Operate the Power Liftgate several times from stop to stop if possible.
6. With the scan tool, read the PLGM DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK FOR A BINDING LIFTGATE
1. Examine the liftgate for proper alignment, worn or binding hinges, weak liftgate prop assembly, loose/hard weatherstrip seal, for wear or anything that would cause an obstruction to proper operation.
2. If necessary manually operate the power liftgate on a known good vehicle and notice the effort needed to open and close for comparison.
  Were there any mechanical problems found?
  
  Yes
  - Refer to STANDARD PROCEDURE .
  - Perform the BODY VERIFICATION TEST, for the related symptom(s). Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE POWER LIFTGATE LATCH
1. With the scan tool, monitor the SECONDARY RATCHET SWITCH CLOSED.
2. Using a screwdriver, click the latch to the closed position while observing the scan tool.
3. Unlatch the latch by pressing the handle switch and observe the scan tool for a change of state.
4. Repeat this step several times while moving the liftgate in different positions and wiggling the harness to check for an intermittent open or shorted circuit.
  Did the scan tool show the switch state changing correctly every time?
  
  Yes
  - Go To 5
  No
  - Go To 4
CHECK THE (Q76) LATCH SECONDARY POSITION SENSE CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the Power Liftgate Latch harness connector.
3. Check for continuity between ground and the (Q76) Latch Secondary Position Sense circuit at the Power Liftgate Latch harness connector.
4. Wiggle the harness while observing the Ohmmeter.
  Is there continuity between ground and the (Q76) Latch Secondary Position Sense circuit?
  
  Yes
  - Repair the (Q76) Latch Secondary Position Sense circuit for a short to ground.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the Power Liftgate Latch assembly in accordance with the Service Information. Refer to LATCH, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE POWER LIFTGATE MODULE - POSITION SENSE OPEN
1. Operate the liftgate from the full closed position and put an obstacle in its path to make it reverse.
  Did the liftgate reverse back to the closed position?
  
  Yes
  - Replace the Power Liftgate Drive Unit in accordance with the service information. Refer to DRIVE UNIT, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 6
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PLGM 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 PLGM 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 Vehicle Scan Report, 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 PLGM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Power Liftgate Module (PLGM) in accordance with the Service Information. Refer to MODULE, POWER LIFTGATE (PLGM), 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.