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
--- | --- | --- | --- | ---
Rear compartment lid ajar switch signal circuit | -- | 1 | -- | --
Rear compartment lid ajar switch ground circuit | -- | 1 | -- | --
1. Trunk ajar indicator does not illuminate while rear compartment lid is open.

### Circuit/System Description

The rear compartment lid can be released by operating the rear compartment lid release switch or by pressing the rear compartment 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

• | Release Systems Schematics

• | Instrument Cluster Schematics

#### Connector End View Reference

• | Displays and Gages Connector End Views

• | Vehicle Access Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Output Controls

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Data List

• | Scan Tool Data Definitions

### Circuit/System Verification

The rear compartment lid ajar indicator should illuminate when the lid is opened and go off when the lid is closed.

### Circuit/System Testing

1. With the ignition OFF, disconnect the harness connector of the rear compartment lid ajar switch.
2. With the ignition ON, connect a fused jumper wire between the rear compartment lid ajar switch signal circuit and the ground circuit of the harness connector.

⇒ | If the rear compartment indicator illuminates, replace the rear compartment lid ajar switch.

⇒ | If the rear compartment lid ajar indicator does not illuminate, test the rear compartment lid ajar switch signal and ground circuits for an open or a high resistance.

3. If all circuits/connections test normal, replace the driver information center (DIC).

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Rear Compartment Lid Latch Replacement

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