Trunk Ajar Indicator Malfunction

Trunk Ajar Indicator Malfunction

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

The interior rear compartment lid release switch receives a signal from the driver door switch assembly (DDSA). When the interior rear compartment lid release switch is activated the signal circuit is pulled to ground. The DDSA interprets this and sends a GMLAN serial data message to the RIM requesting the rear compartment lid be released. The rear integration module (RIM) grounds the trunk release relay control circuit which energizes the TRK DR REL relay. The trunk release relay is supplied with battery voltage at all times. With the relay coil energized, the relay switch contacts close allowing battery voltage to flow to the rear compartment lid release actuator causing the rear compartment lid to release. The rear compartment lid release actuator is permanently grounded at G402. When the rear compartment lid release actuator releases the rear compartment lid, the rear compartment lid ajar switch, which is internal the rear compartment lid release actuator, is supplied with ground which causes the trunk ajar switch signal circuit to be pulled low. The trunk ajar switch signal circuit is an input to the RIM. When the RIM receives a trunk ajar signal, a GMLAN serial data message is sent to the instrument panel cluster (IPC) requesting the TRUNK OPEN message be displayed on the message center.


The exterior rear compartment lid release switch receives a signal from the remote control door lock receiver (RCDLR). When the exterior rear compartment lid release switch is activated the signal circuit is pulled to ground. The RCDLR interprets this and sends a GMLAN serial data message to the RIM requesting the rear compartment lid be released. The rear integration module (RIM) grounds the trunk release relay control circuit which energizes the TRK DR REL relay. The trunk release relay is supplied with battery voltage at all times. With the relay coil energized, the relay switch contacts close allowing battery voltage to flow to the rear compartment lid release actuator causing the rear compartment lid to release. The rear compartment lid release actuator is permanently grounded at G402.


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) for scan tool information


Circuit/System Verification

Ignition ON, observe the scan tool rear compartment lid ajar parameter while opening and closing the trunk. The reading should toggle between CLOSED and AJAR.


Circuit/System Testing

1. Ignition ON, trunk OPEN, observe the scan tool rear compartment lid ajar parameter. The scan tool should display AJAR and the TRUNK OPEN indicator should be ON.

• If the scan tool displays AJAR and the TRUNK OPEN indicator is not ON, replace the IPC.

2. Ignition ON, trunk CLOSED, observe the scan tool rear compartment lid ajar parameter. The scan tool should display CLOSED and the TRUNK OPEN indicator should be OFF.

• If the scan tool displays CLOSED and the TRUNK OPEN indicator is ON, replace the IPC.

3. Ignition OFF, disconnect the harness connector at the rear compartment lid release actuator.
4. Ignition OFF, test for less than 5.0 ohms between the ground circuit terminal B and ground.

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

5. Ignition ON, verify the scan tool rear compartment lid ajar parameter is CLOSED.

• If not the specified value, test the signal circuit terminal C for a short to ground. If the circuit tests normal, replace the RIM.

6. Install a 3-amp fused jumper wire between the signal circuit terminal C and ground. Verify the scan tool rear compartment lid ajar parameter is AJAR.

• 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 RIM.

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



Repair Instructions

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

* Rear Compartment Lid Switch Replacement (Exterior) (Service and Repair)
* Control Module References (Programming and Relearning) for RIM replacement, setup, and programming