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Trunk Release Inoperative



Trunk Release Inoperative

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



Diagnostic Fault Information






Circuit/System Description

When the rear compartment lid release switch is operated, the rear compartment lid release switch signal circuit to the body control module (BCM) is switched to ground. The BCM receives the rear compartment lid release switch input and applies ground to the rear compartment lid relay control circuit. This energizes the trunk release relay coil, closing the switch side contacts, allowing battery voltage to be applied to the rear compartment lid release actuator and folding top cover actuator, releasing the buttresses and opening the rear compartment lid. Ground for the rear compartment lid release switch is provided at G300. The rear compartment lid ajar switch, rear compartment lid release actuator, and folding top cover actuator are provided ground at G301.


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 (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)


Circuit/System Verification

1. Ignition ON, observe the scan tool trunk release switch parameter while pressing the rear compartment lid release switch. The reading should change between ACTIVE and INACTIVE.

• If the reading does not change as the switch is activated, refer to Rear Compartment Lid Release Switch Malfunction.

2. Ignition ON, command the trunk release ON and OFF with a scan tool. The folding top cover and rear compartment lid should release.

• If the folding top cover or rear compartment lid release actuators do not release, refer to Rear Compartment Lid Release 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. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal A.

• If the test lamp does not illuminate, 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 circuit tests normal, replace the BCM.

4. Install a 3-amp fused jumper wire between the signal circuit terminal C and the ground circuit terminal A. 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 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 trunk release relay.
2. Ignition ON, verify that a test lamp does not illuminate between the relay switch control circuit terminal 87 and ground.

• If the test lamp illuminates, test the controlled output circuit for a short to voltage.

3. Verify that a test lamp illuminates between the relay coil B+ circuit terminal 85 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. Verify that a test lamp illuminates between the relay switch B+ circuit terminal 30 and ground.

• If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

5. Disconnect the harness connector at the folding top cover actuator.
6. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms of resistance between the folding top cover actuator ground circuit terminal B and ground.

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

7. Connect the harness connector at the folding top cover actuator.
8. Connect a 3-amp fused jumper wire between the relay switch B+ circuit terminal 30 and the relay switch controlled output circuit terminal 87. Verify the folding top cover actuator is activated.

• If the folding top cover actuator 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 folding top cover actuator.

9. Disconnect the harness connector at the rear compartment lid release actuator.
10. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms of resistance between the rear compartment lid release actuator ground circuit terminal B and ground.

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

11. Connect the harness connector at the rear compartment lid release actuator.
12. Connect a 3-amp fused jumper wire between the relay switch B+ circuit terminal 30 and the relay switch controlled output circuit terminal 87. Verify the rear compartment lid release actuator is activated.

• If the rear compartment lid release actuator 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 rear compartment lid release actuator.

13. Connect a test lamp between the relay coil B+ circuit terminal 85 and the relay coil control circuit terminal 86.
14. 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.

15. If all circuits test normal, test or replace the trunk release relay.



Component Testing


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 ground terminal and the signal terminal with the switch in the open position.

• If less than infinite resistance, replace the switch.

3. Test for less than 1 ohm resistance between the ground terminal and the signal terminal with the switch in the closed position.

• If greater than 1 ohm, replace the rear compartment lid release switch.




Trunk Release Relay
1. Ignition OFF, disconnect the trunk release relay.
2. Test for 60-180 ohms resistance between terminals 85 and 86.

• If the resistance is not within the specified range, replace the trunk release relay.

3. Test for infinite resistance between the following terminals:

* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87

4. Install a 20-amp fused jumper between relay terminal 85 and 12 volts. Install a jumper between relay terminal 86 and ground. Test for less than 2.0 ohms resistance between terminals 30 and 87.

• If greater than 2.0 ohms, replace the trunk release relay.




Rear Compartment Lid Release Actuator and Folding Top Cover Actuator
1. Ignition OFF, disconnect the actuator.
2. Install a 10-amp fused jumper between the voltage supply circuit and 12 volts. Install a jumper between the ground terminal and ground. Verify the actuator activates.

• If the actuator does not activate, replace the rear compartment lid release actuator.




Repair Instructions

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

* Rear Compartment Lid Latch Replacement (Service and Repair)
* Rear Compartment Lid Switch Replacement (Service and Repair)
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Rear Compartment Lid Buttress Latch Release Cable Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup and programming


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