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 body control module (BCM) receives a discrete input from the rear compartment lid ajar switch signal circuit. When the rear compartment is opened, the normally open rear compartment lid ajar switch closes. With the rear compartment lid ajar switch closed, ground is provided to the rear compartment lid ajar switch signal circuit. The BCM interprets this and communicates via GMLAN serial data with the instrument panel cluster (IPC). When the rear compartment is open/ajar and the vehicle is in any gear other than PARK, the driver information center (DIC) will display TRUNK AJAR. If the rear compartment is still ajar and the vehicles speed is greater than 4.8 km/h (3 mph) a chime will sound.
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
Ignition ON, observe the scan tool trunk ajar switch parameter while opening and closing the trunk. The reading should toggle between TRUNK CLOSED and TRUNK AJAR.
Circuit/System Testing
1. Ignition ON, trunk OPEN, observe the scan tool trunk ajar switch parameter. The scan tool should display TRUNK AJAR and the TRUNK AJAR indicator should be ON.
• If the scan tool displays TRUNK AJAR and the TRUNK AJAR indicator is not ON, replace the IPC.
2. Ignition ON, trunk CLOSED, observe the scan tool trunk ajar switch parameter. The scan tool should display TRUNK CLOSED and the TRUNK AJAR indicator should be OFF.
• If the scan tool displays TRUNK CLOSED and the TRUNK AJAR indicator is ON, replace the IPC.
3. Ignition OFF, disconnect the harness connector at the rear compartment lid ajar switch.
4. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms of resistance 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 trunk ajar switch parameter displays TRUNK CLOSED.
• If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.
6. Install a 3A fused jumper wire between the trunk ajar switch signal circuit terminal A and ground. Verify the scan tool trunk ajar switch parameter displays TRUNK 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 BCM.
7. If all circuits tests normal, test or replace the rear compartment lid ajar switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Rear Compartment Latch Striker Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM or IPC replacement, setup and programming