Diagnostic Test

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

CHECK ACTIVE FOR 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-11-LIFTGATE CONTROL CIRCUIT 1 - CIRCUIT SHORT TO GROUND?
  
  Yes
  - Go To 2
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct pin tension.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
ISOLATE AND CHECK THE (Q88) LIFTGATE OPEN DRIVER CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT AT THE POWER LIFTGATE DRIVE UNIT (PLDU) HARNESS CONNECTOR
1. The ignition must be off when performing a resistance check to find a short between circuits.
2. Isolate the circuit by disconnecting the Power Liftgate Drive Unit C1 harness connector and every component containing the circuit being tested. At this time leave all in-line connectors connected. Note: Use the wiring diagram as a guide to follow the path of the circuit.
3. Connect one lead of the DVOM to the circuit being tested at the Power Liftgate Drive Unit C1 harness connector.
4. With the other lead of the DVOM probe all other circuits at the Power Liftgate Drive Unit C1 harness connector.
  NOTE:
  With the resistance between the circuit being tested and any other circuit.
  
  Is there resistance between the circuit being tested and any other circuit?
  
  Yes
  - Repair the short between the circuits that have continuity. Use the wiring diagram as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
POWER LIFTGATE DRIVE UNIT (PLDU) OR POWER LIFTGATE MODULE (PLGM)
1. Replace the Power Liftgate Drive Unit in accordance with the Service Information. Refer to DRIVE UNIT, POWER, REMOVAL .
2. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged
3. With the scan tool, erase the DTCs.
4. Turn the ignition off, wait 10 seconds, then turn the ignition on.
5. If possible, operate the liftgate several times.
6. With the scan tool, read the Active DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Power Liftgate Module in accordance with the Service Information. Refer to MODULE, POWER LIFTGATE CONTROL (PLGM), REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  - Test Complete.