Liftgate Release Malfunction
Liftgate Release Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The liftgate can be released by pressing the liftgate touch-pad located in the handle above the license plate. All doors must be unlocked, the transaxle must be in park or a vehicle with a manual transaxle, the vehicle must be stationary for the liftgate to release.
Pressing the liftgate release switch closes a contact providing a ground for the liftgate release switch signal circuit. The body control module (BCM) will detect the voltage drop and command voltage to be supplied to the liftgate release relay control circuit thus energizing the L/GATE RELSE relay which provides voltage to the release actuator releasing the liftgate.
Diagnostic Aids
Before testing can be performed, the liftgate must be opened. Refer to Opening the Liftgate Without Electrical Power (Procedures) for the appropriate procedure.
An intermittent short to ground in the Liftgate Release Switch Signal circuit may cause the BCM to command the liftgate to open if the vehicle is in park and the doors are unlocked. If the vehicle has a history of the liftgate opening unexpectedly, inspect the point where the wires enter the exterior liftgate handle switch for corrosion or evidence of water intrusion.
Reference Information
Schematic Reference
Release Systems Schematics (Release Systems Schematics)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Rear Hatch/Gate Description and Operation (Description and Operation)
Electrical Information Reference
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Circuit Testing (Circuit Testing)
* Wiring Repairs (Wiring Repairs)
* Connector Repairs (Connector Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Verification
1. Ignition ON, observe the scan tool Liftgate Release Sw parameter while pressing and releasing the liftgate release switch. The parameter should change between Active and Inactive.
• If the value does not change, refer to Liftgate Release Switch Malfunction.
2. With the doors unlocked, command the liftgate door latch to release by pressing the liftgate release switch. The liftgate door latch should release the liftgate.
• If the liftgate door latch does not release the liftgate, refer to Liftgate Release Malfunction.
Circuit/System Testing
Liftgate Release Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the liftgate release switch.
2. Test for less than 1 ohm between the ground circuit terminal D and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Liftgate Release Sw. parameter is Inactive.
• If not the specified value, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool Liftgate Release Sw. parameter is Active.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the liftgate release switch.
Liftgate Release Malfunction
1. Ignition OFF, disconnect the L/GATE RELSE relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage.
3. Verify that a test lamp illuminates between the B+ circuit terminal 30 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Ignition OFF, disconnect the harness connector at the liftgate door latch.
5. Test for less than 1 ohm between the ground circuit terminal 3 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
6. Connect the harness connector at the liftgate door latch.
7. Ignition ON, connect a 20A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the liftgate door latch is activated.
• If the liftgate door latch does not activate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the liftgate door latch.
8. Connect a test lamp between the control circuit terminal 86 and B+.
9. Command the liftgate release ON and OFF by pressing and releasing the liftgate release switch. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always OFF, test the control circuit for an open/high resistance.
• If the test lamp is always ON, test the control circuit for a short to ground.
10. Connect a test lamp between the control circuit terminal 85 and ground.
11. Command the liftgate release actuator ON and OFF by pressing and releasing the liftgate release switch. The test lamp should turn ON and OFF while changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
12. If all circuits test normal, test or replace the L/GATE RELSE relay.
Component Testing
Release Actuator, Door Latch - Liftgate
1. Ignition OFF, disconnect the harness connector at the liftgate door latch.
2. Install a 20A fused jumper wire between the control terminal 1 and 12 V. Install a jumper wire between the ground terminal 3 and ground. Verify the release actuator activates.
• If the actuator does not perform as specified, replace the liftgate door latch.
Liftgate Release Switch
1. Ignition OFF, disconnect the harness connector at the liftgate release switch.
2. Test for infinite resistance between the signal terminal B and the ground terminal D with the switch in the open position.
• If not the specified value, replace the liftgate release switch.
3. Test for less than 2 ohm between the signal terminal B and the ground terminal D with the switch in the closed position.
• If greater than the specified range, replace the liftgate release switch.
Relay Test
1. Ignition OFF, disconnect the L/GATE RELSE relay.
2. Test for 60-180 ohm between terminals 85 and 86.
• If not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If not the specified value, replace the relay.
4. Install a 3A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohm between terminals 30 and 87.
• If greater than the specified range, replace the relay.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Relay Replacement Removal and Replacement
* Liftgate Outside Handle Replacement (Liftgate Outside Handle Replacement)
* Liftgate Latch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup and programming