Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
If there are any other Power Liftgate Module (PLGM) DTCs present, correct them before proceeding with this test.
1. Make sure the battery is fully charged and vehicle charging system is operating properly.
2. Turn the ignition on.
3. Make sure the liftgate is closed and with the scan tool, run the "Latch Home Sector Test" before proceeding to ensure the latch is positioned correctly.
4. With the scan tool, create a Vehicle Scan Report and attach it to the repair order.
5. Erase the DTCs.
6. Turn the ignition off, wait 10 seconds, then turn the ignition on.
7. Operate the power liftgate several times if possible.
8. 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, and track assembly 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.
3. Especially notice the effort needed to unlatch and close the liftgate.
  Were there any mechanical problems found?
  
  Yes
  - Refer to STANDARD PROCEDURE for the related symptom(s).
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (Q84) LIFTGATE LATCH CINCH DRIVER CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Power Liftgate Module (PLGM) C2 harness connector.
3. Disconnect the Power Liftgate Latch connector.
4. Check connectors for corrosion, damage, or pushed out terminals. Repair as necessary.
5. Measure the resistance of the (Q84) Liftgate Latch Cinch Driver circuit between the PLGM C2 connector and the Power Liftgate Latch connector.
6. Wiggle the harness and check for an intermittent open condition.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (Q84) Liftgate Latch Cinch Driver circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (Q85) LIFTGATE LATCH RELEASE DRIVER CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (Q85) Liftgate Latch Release Driver circuit between the PLGM C2 connector and the Power Liftgate Latch connector.
2. Wiggle the harness and check for an intermittent open condition.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (Q85) Liftgate Latch Release Driver circuit for high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (Q901) LOGIC GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (Q901) Logic Ground circuit between the PLGM C2 harness connector and the PLGM Latch harness connector.
2. Wiggle the harness and check for an intermittent short condition.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (Q901) Logic Ground circuit for high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (G78) LIFTGATE AJAR SWITCH SENSE CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (G78) Liftgate Ajar Switch Sense circuit between the PLGM C2 connector and the PLGM Latch connector.
2. Wiggle the harness and check for an intermittent open condition.
  Is the resistance below 2.0 Ohms?
  
  Yes
  - Replace the Power Liftgate Latch in accordance with the Service Information and using the scan tool, run the "Latch Home Sector Test". Refer to LATCH, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Repair the (G78) Liftgate Ajar Switch Sense circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .