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 power open operation.
1. With the scan tool, record and erase 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 Active DTCs.
  Does the scan tool display; B25BA-00 - POWER LIFTGATE OPEN DIRECTION - SECTOR 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
LATCH HOME POSITION
1. With the scan tool in Inputs/Outputs, read the "Sector Gear Switch Closed" state.
  Does the scan tool display; YES?
  
  Yes
  - Go To 5
  No
  - Go To 4
POWER LIFTGATE LATCH
1. Disconnect the Power Liftgate Latch harness connector.
2. With the scan tool, monitor the Sector Gear Switch Closed state.
3. Connect a jumper wire between the (Q79) Sector Switch Sense circuit and the (Q901) Sensor Ground circuit.
4. Repeat the previous step several times by disconnecting and connecting the jumper while observing the scan tool.
  Did the scan tool show the switch state changing correctly every time the jumper was connected and disconnected?
  
  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
  - Go To 5
ISOLATE AND CHECK THE (Q901) LOGIC GROUND CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Turn all lights off.
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 6
  No
  - Repair the (Q901) Logic Ground circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
ISOLATE AND CHECK THE (Q79) SECTOR SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance between the (Q901) Logic Ground circuit and the (Q79) Sector Switch Sense circuit.
2. Wiggle the harness while observing the ohmmeter.
  Is the resistance below 100.0 Ohms?
  
  Yes
  - Go To 8
  No
  - Go To 7
ISOLATE AND CHECK THE (Q79) SECTOR SWITCH SENSE CIRCUIT FOR AN OPEN
1. Disconnect the Power Liftgate Module C2 harness connector.
2. Measure the resistance of the (Q79) Sector Switch Sense circuit between the Power Liftgate 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?
  
  No
  - Repair the (Q79) Sector Switch Sense circuit for an open.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  Yes
  - Go To 8
ISOLATE AND CHECK THE (Q79) SECTOR SWITCH SENSE CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage of the (Q79) Sector Switch Sense circuit.
3. Wiggle the harness while observing the voltmeter.
  Is there any voltage present?
  
  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 .
  Yes
  - Repair the (Q79) Sector Switch Sense circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
ISOLATE AND CHECK THE (Q79) SECTOR SWITCH SENSE CIRCUIT FOR A SHORT TO THE (Q901) LOGIC GROUND CIRCUIT
1. Disconnect the Power Liftgate Latch harness connector.
2. Measure the resistance between the (Q901) Logic Ground circuit and the (Q79) Sector Switch Sense circuit.
3. Wiggle the harness while observing the ohmmeter.
  Is the resistance below 1, 000 Ohms?
  
  Yes
  - Go To
  No
  - 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 .
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.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
5. Connect all PLGM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect 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. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read 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
  - Replace the Power Liftgate Drive Unit in accordance with the Service Information. Refer to DRIVE UNIT, POWER, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .