GM Service Manual Online
For 1990-2009 cars only

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

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--

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1. Trunk ajar indicator always ON.

Circuit/System Description

The rear compartment lid can be released by operating the rear compartment lid release switch or 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 low speed GMLAN 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

    •  Vehicle Access Connector End Views
    •  Displays and Gages Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls
    •  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 rear compartment lid ajar switch.
  2. With the ignition ON and the rear compartment lid closed, verify the status of the rear compartment lid ajar indicator.
  3. If the rear compartment indicator is not illuminated, replace the ajar switch.
    If the rear compartment lid ajar indicator is still illuminated, test the rear compartment lid ajar switch signal circuit for a short to ground.
  4. 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 IPC replacement, setup, and programming