For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Trunk Release Relay Control | B3265 06 | B3265 06 | B3265 01 | --
Rear Compartment Lid Ajar Switch Signal | 2 | 3 | 3 | --
Rear Compartment Lid Release Actuator Control | 1 | 1 | 1 | --
Rear Compartment Lock Actuator Unlock Signal | 1 | 1 | 1 | --
Rear Compartment Lid Release Actuator Ground | -- | 1 | -- | --
Rear Compartment Lid Ajar Switch Ground | -- | 3 | -- | --
Rear Compartment Lid Release Switch Ground | -- | 1 | -- | --
1. Trunk Release Inoperative 2. Trunk Ajar Indicator Always On 3. Trunk Ajar Indicator Inoperative

### Circuit/System Description

The driver information center (DIC) located at the bottom of the instrument panel cluster (IPC), illuminates the TRUNK AJAR indicator when the body control module (BCM) detects that the rear compartment lid ajar switch is closed to ground indicating the rear compartment lid is open. The IPC receives a GMLAN serial data message from the BCM indicating the rear compartment lid ajar status. If this message is displayed and the vehicle speed is greater than 4.8 km/h (3 mph), a chime will sound. For more detailed information concerning rear compartment lid release refer to Luggage Compartment Description and Operation .

### Reference Information

#### Schematic Reference

Instrument Cluster Schematics

#### Connector End View Reference

Displays and Gages Connector End Views

#### Electrical Information Reference

• | Testing for Intermittent Conditions and Poor Connections

• | Circuit Testing

• | Wiring Repairs

• | Connector Repairs

#### Scan Tool Reference

• | Scan Tool Output Controls

• | Scan Tool Data List

• | Scan Tool Data Definitions

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the rear compartment lid ajar switch.
2. Ignition OFF, test for less than 1 ohm resistance between the ground circuit terminal B and ground.

⇒ | If greater than 1 ohm, test the ground circuit for an open/high resistance.

3. Using a scan tool, verify the Trunk Ajar Switch parameter displays 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 between the rear compartment lid ajar switch signal circuit terminal A and ground. With a scan tool, verify the Trunk Ajar Switch parameter displays Trunk Ajar.

⇒ | If not Trunk Ajar, test the rear compartment lid ajar switch 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 ajar switch.

### Component Testing

1. Ignition OFF, disconnect the harness connector at the rear compartment lid ajar switch.
2. Test for infinite resistance between terminals A and B with the switch in the open position.

⇒ | If less than infinite resistance, replace the switch.

3. Test for less than 1 ohm resistance between terminals A and B with the switch in the closed position.

⇒ | If greater than 1 ohm, replace the switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Rear Compartment Lid Latch Replacement

• | Control Module References for BCM replacement, setup and programming