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 FOR ACTIVE DTCS
NOTE:
This DTC will only set during the cinching operation after the four second time out. This may make it difficult to reproduce.
1. With the scan tool, record and erase the DTCs.
2. Turn the ignition off, wait 10 seconds, then turn the ignition on.
3. Operate the power liftgate several times if possible.
4. With the scan tool, read the Active DTCs.
  Does the scan tool display; B25B7-00 - POWER LIFTGATE CLOSE DIRECTION - RATCHET PRIMARY SWITCH INVALID STATE?
  
  Yes
  - Go To 2
  No
  - Using the wiring diagram/schematic as a guide, inspect the wiring and connectors for an intermittent condition. Operate the door several times and check for any binding or other obstructions.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK FOR A BINDING LIFTGATE
1. Examine the liftgate for proper fit and alignment, loose/hard or torn seals, misaligned latch striker or anything that would cause an obstruction to proper operation.
2. Manually operate the liftgate of a known good vehicle and notice the effort needed to open and close.
3. Compare the effort needed on the disabled liftgate.
4. Especially notice the effort needed to unlatch and close the liftgate.
  Does it take more effort to operate the liftgate than it should?
  
  Yes
  - Refer to Standard Procedures according to the Service Information. Refer to STANDARD PROCEDURE - LIFTGATE OPERATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
POWER LIFTGATE MODULE
1. With the scan tool, monitor the PRIMARY RATCHET SWITCH.
2. Using a screwdriver, click the latch to the second detent 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 4
  No
  - 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 .
CHECK THE (Q901) LOGIC GROUND CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the Power Liftgate Latch harness connector.
3. Measure the resistance between ground and the (Q901) Logic Ground circuit.
4. Wiggle the harness while observing the ohmmeter.
  Is the resistance below 9.5 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (Q901) Logic Ground circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (G78) LIFTGATE AJAR SWITCH SENSE CIRCUIT FOR AN OPEN
1. Disconnect the Power Liftgate Module C2 harness connector.
2. Measure the resistance of the (G78) Liftgate Ajar Switch Sense circuit between the Power Liftgate C2 connector and the Power Liftgate Latch connector.
3. Wiggle the harness while observing the ohmmeter.
  Is the resistance below 1.0 Ohms?
  
  Yes
  - Replace the Power Liftgate Latch assembly in accordance with the Service Information. Refer to LATCH, LIFTGATE, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Repair the (G78) Liftgate Ajar Switch Sense circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .