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 the DTCs.
4. Turn the ignition off, wait 10 seconds, then turn the ignition on.
5. Operate the power liftgate several times 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, or loose/hard weather strip for wear or anything that would cause an obstruction to proper operation. Check for the possibility of the liftgate having been overloaded due to ice or heavy snow.
2. Raise the liftgate and check the struts for proper operation.
3. If necessary manually operate the liftgate of a known good vehicle and notice the effort needed.
4. Compare the effort needed on the disabled vehicle.
  Were there any mechanical problems found?
  
  Yes
  - Refer to POWER LIFTGATE, STANDARD PROCEDURE for the related symptom(s).
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE SECONDARY RATCHET SWITCH
1. Open the liftgate to the middle position.
2. With the scan tool, monitor the Secondary Ratchet Switch.
3. Using a screwdriver, click the latch to the fully closed position while observing the scan tool.
4. Unlatch the latch by pressing the handle switch and observe the scan tool for a change of state.
5. Repeat this step several times while moving the liftgate in different positions and wiggling the harness to check for an intermittent shorted circuit.
  Did the scan tool show the switch state changing correctly every time?
  
  Yes
  - Go To 4
  No
  - Go To 8
CHECK THE (Q89) LIFTGATE CLOSE DRIVER CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the PLGM C1 connector.
3. Turn the ignition on.
4. Measure the voltage between the (Q89) liftgate Close Driver circuit and ground at the PLGM C1 connector.
  Is there any voltage present?
  
  Yes
  - Repair the (Q89) liftgate Close Driver circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (Q88) LIFTGATE OPEN DRIVER CIRCUIT FOR A SHORT TO THE (Q89) LIFTGATE CLOSE DRIVER CIRCUIT
1. Turn the ignition off.
2. Check for continuity between the (Q88) liftgate Open Driver circuit and the (Q89) liftgate Close Driver circuit at the PLGM C1 connector.
  Is there continuity between the (Q88) liftgate Open Driver circuit and the (Q89) liftgate Close Driver circuit?
  
  Yes
  - Go To 6
  No
  - Go To 7
CHECKING THE (Q88) LIFTGATE OPEN DRIVER CIRCUIT FOR A SHORT TO THE (Q89) LIFTGATE CLOSE DRIVER CIRCUIT DISCONNECTED FROM THE POWER LIFTGATE DRIVE UNIT
1. Disconnect the Power Liftgate Drive Unit connector.
2. Check for continuity between the (Q88) liftgate Open Driver circuit and the (Q89) liftgate Close Driver circuit at the PLGM C1 connector.
  Is there continuity between the (Q88) liftgate Open Driver circuit and the (Q89) liftgate Close Driver circuit?
  
  Yes
  - Repair the (Q88) liftgate Open Driver circuit for a short to the (Q89) liftgate Close Driver circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the Power Liftgate Drive Unit in accordance with service information. Refer to DRIVE UNIT, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE POWER LIFTGATE DRIVE UNIT
1. Re-connect the PLGM C1 connector.
2. Operate the Power Liftgate in both directions if possible.
  Does the motor start to lift the liftgate but is very slow and labors extensively?
  
  Yes
  - Replace the Power Liftgate Drive Unit assembly 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 11
CHECK THE (Q60) LIFTGATE SECONDARY LATCH SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the Power Liftgate Latch connector.
3. Check for continuity between ground and the (Q60) Liftgate Secondary Latch Signal circuit.
4. Wiggle the harness while observing the Ohmmeter.
  Is the resistance below 1K Ohms?
  
  Yes
  - Repair the (Q60) Liftgate Secondary Latch Signal circuit for a short to ground.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 9
CHECK THE (Q60) LIFTGATE SECONDARY LATCH SIGNAL CIRCUIT FOR AN OPEN
1. Disconnect the PLGM C2 harness connector.
2. Measure the resistance of the (Q60) Liftgate Secondary Latch Signal Circuit between the PLGM C2 harness connector and the Power Liftgate Latch harness connector.
3. Wiggle the harness while observing the Ohmmeter.
  Is the resistance below 1.0 Ohm?
  
  Yes
  - Go To 10
  No
  - Repair the (Q60) Liftgate Secondary Latch Signal circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (Q60) LIFTGATE SECONDARY LATCH SIGNAL WIRE SHORTED TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage between ground and the (Q60) Liftgate Secondary Latch Signal circuit.
3. Wiggle the harness while observing the voltmeter.
  Is there any voltage present?
  
  Yes
  - Repair the (Q60) Liftgate Secondary Latch Signal circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Replace the Power Liftgate Latch in accordance with the Service Information. Refer to LATCH, LIFTGATE, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
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 DRIVE UNIT, 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.