Trunk Release Inoperative

Trunk Release Inoperative

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

When the rear compartment lid release switch is pushed, the rear compartment lid release signal circuit to the body control module (BCM) is grounded. When the rear compartment lid release signal circuit is grounded, the BCM grounds the coil side of the trunk release relay through the trunk release relay control circuit. With ground applied to the coil side of the trunk release relay, voltage is applied to the rear compartment lid release actuator, opening the rear compartment.

Reference Information
Schematic Reference

Release Systems Schematics (Release Systems Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Luggage Compartment Description and Operation (Sedan) (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition ON, observe the scan tool Trunk Release Switch parameter while pressing and releasing the rear compartment lid release switch. The parameter should change between Active and Inactive.

• If the value does not change between Active and Inactive, refer to Rear Compartment Lid Switch Malfunction.

2. Command the trunk release with a scan tool. The rear compartment lid release actuator should release the trunk lid.

• If the trunk latch does not does not release, refer to Rear Compartment Lid Malfunction.

Circuit/System Testing

Rear Compartment Lid Release Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the rear compartment lid release switch.
2. Test for less than 1 ohm between the ground circuit terminal A and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Trunk Release Switch parameter is Inactive.

• If not the specified value, test the signal circuit terminal C 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 C and ground. Verify the scan tool Trunk Release Switch 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 rear compartment lid release switch.

Rear Compartment Lid Release Malfunction
1. Ignition OFF, disconnect the X2 harness connector at the underhood fuse block.
2. Connect a test lamp between the control circuit terminal B10 and B+.
3. Ignition ON, command the trunk release ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

4. Ignition OFF, connect the harness connector at the underhood fuse block and disconnect the harness connector at the rear compartment lid release actuator.
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 a test lamp between the control circuit terminal 4 and ground.
7. Ignition ON, command the trunk release ON and OFF with a scan tool. The test lamp should turn ON and OFF when 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 underhood fuse block.
• If the test lamp is always OFF and the circuit fuse is good, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the underhood fuse block.
• If the test lamp is always OFF and the circuit fuse is open, test the control circuit for a short to ground. If the circuit tests normal, test or replace the rear compartment lid release actuator.

8. If all circuits test normal, test or replace the rear compartment lid release actuator.

Component Testing

Rear Compartment Lid Release Actuator
1. Ignition OFF, disconnect the harness connector at the rear compartment lid release actuator.
2. Install a 20-amp fused jumper wire between the control terminal 4 and 12 volts. Momentarily install a jumper wire between the ground terminal 3 and ground. Verify the rear compartment lid release actuator activates.

• If the actuator does not perform as specified, replace the rear compartment lid release actuator.

Rear Compartment Lid Release Switch
1. Ignition OFF, disconnect the harness connector at the rear compartment lid release switch.
2. Test for infinite resistance between the signal terminal C and the ground terminal A with the switch in the open position.

• If not the specified value, replace the rear compartment lid release switch.

3. Test for less than 2 ohms between the signal terminal C and the ground terminal A with the switch in the closed position.

• If greater than the specified range, replace the rear compartment lid release switch.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Underhood Electrical Center or Junction Block Bracket Replacement (Removal and Replacement)
* Rear Compartment Lid Latch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming