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 rear compartment lid can be released by operating the rear compartment lid release switch or by pressing the rear compartment lid release button on the remote keyless entry transmitter. The gear selector may be in any position, but the vehicle speed must equal 0 for the rear compartment lid to release.


When the ignition is ON, the body control module (BCM) supplies battery positive voltage to the rear compartment lid ajar switch through the rear compartment lid ajar switch signal circuit. When the rear compartment lid is opened, the signal circuit is connected to ground through the rear compartment lid ajar switch ground circuit and the voltage is pulled low within the BCM. In response, the BCM sends a serial data message to the driver information center (DIC) in the instrument panel cluster (IPC) to illuminate the rear compartment lid ajar indicator.


Reference Information
Schematic Reference

* Instrument Cluster Schematics (Instrument Cluster Schematics)
* Release Systems Schematics (Release Systems Schematics)

Connector End View Reference

Component Connector End Views (Connector Views)
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

With the ignition key ON, the rear compartment lid ajar indicator should illuminate when the rear compartment lid is opened and go off when the rear compartment lid is closed.


Circuit/System Testing

1. Ignition OFF, disconnect the X1 harness connector of the rear compartment lid latch.
2. Test for less than 1.0 ohm of resistance between the rear compartment lid ajar switch ground circuit and ground.

• If greater than 1.0 ohm, test the ground circuit for an open/high resistance.

3. Ignition ON, using a scan tool, verify the Trunk Ajar Switch parameter is trunk closed.

• If not trunk closed, test the rear compartment lid ajar switch signal circuit for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3-amp fused jumper wire between the signal circuit and ground. Verify the Trunk Ajar Switch parameter is trunk ajar.

• If not trunk ajar, 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 latch.



Component Testing

1. Ignition OFF, disconnect the harness connector at the rear compartment lid latch.
2. Test for infinite resistance between the signal terminal and the ground terminal with the ajar switch in the open position.

• If less than infinite resistance, replace the rear compartment lid latch.

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

• If greater than 3 ohms, replace the rear compartment lid latch.

4. Test for infinite resistance between each terminal and the rear compartment lid latch housing/case.

• If less than infinite resistance, replace the rear compartment lid latch.




Repair Instructions

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

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