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Trunk Ajar Indicator Malfunction




Trunk Ajar Indicator Malfunction

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

The body control module (BCM) supplies a 12V signal to the rear compartment lid ajar switch signal circuit. When the rear compartment lid release actuator releases the rear compartment lid, the rear compartment lid ajar switch, which is internal to the rear compartment lid release actuator causes the trunk ajar switch signal circuit to be pulled low. The BCM interprets this and communicates via serial data with the instrument panel cluster (IPC). When the trunk is open/ajar and the vehicle is in any gear other than PARK, the driver information center (DIC) will display TRUNK OPEN. If the trunk is still open and the vehicle speed is greater than 5 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 Luggage Compartment
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 Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Rear Closure Ajar Sw. parameter while opening and closing the trunk. The parameter should change between Inactive and Active.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the M40 rear compartment lid latch.
2. Ignition ON, verify the scan tool Rear Closure Ajar Sw. parameter is Inactive.

If not the specified value, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the K9 BCM.

* Terminal C-Sedan
* Terminal 3-Coupe

3. Install a 3A fused jumper wire between the signal circuit terminal listed below and ground. Verify the scan tool Rear Closure Ajar Sw. parameter is Active.

If not the specified value, test the signal circuit terminal listed below for a short to voltage or and open/high resistance. If the circuit tests normal, replace the K9 BCM.

* Terminal C-Sedan
* Terminal 3-Coupe

4. If all circuits test normal, test or replace the M40 rear compartment lid latch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the M40 rear compartment lid latch.
2. Test for infinite resistance between the terminals listed below with the switch in the open position.

* Terminal C and terminal B-Sedan
* Terminal 3 and terminal 2-Coupe

If not the specified value, replace the M40 rear compartment lid latch.

3. Test for less than 2 ohm between the terminals listed below with the switch in the closed position.

* Terminal C and terminal B-Sedan
* Terminal 3 and terminal 2-Coupe

If greater than the specified range, replace the M40 rear compartment lid latch.

Repair Instructions

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

* Rear Compartment Lid Latch Replacement (Coupe) Rear Compartment Lid Latch Replacement (Coupe)Rear Compartment Lid Latch Replacement (Sedan) Rear Compartment Lid Latch Replacement (Sedan)
* Control Module References Control Module References for BCM replacement, setup and programming