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 Lamp Control

1

1

1

--

Rear Comapartment Lamp Ground

--

1

--

--

1. Rear Compartment Lamp Malfunction

Circuit/System Description

The rear compartment lamp is supplied voltage from the BCM via the inadvertent power courtesy lamp control circuit. When the rear compartment lid is open, the rear compartment courtesy lamp switch is closed, providing a ground path for the rear compartment courtesy lamp and illuminating the lamp.

Reference Information

Schematic Reference

Interior Lights Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Interior Lighting Systems Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the rear compartment courtesy lamp.
  2. Ignition ON, verify a test lamp illuminates between the control circuit terminal A and ground.
  3. If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
  4. Ignition OFF, connect the harness connector at the rear compartment courtesy lamp. Disconnect the harness connector at the rear compartment lid latch.
  5. Test for less than 10 ohms between the ground circuit terminal 3 and ground.
  6. If greater than the specified range, test the ground circuit for an open/high resistance.
  7. Ignition ON, verify the rear compartment courtesy lamp is not illuminated.
  8. If the rear compartment courtesy lamp is illuminated, test the control circuit terminal 1 for a short to ground.
  9. Install a 5A fused jumper wire between the control circuit terminal 1 and ground. Verify the rear compartment courtesy lamp is illuminated.
  10. If the rear compartment courtesy lamp does not illuminate, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the test the rear compartment courtesy.
  11. If all circuits test normal, test or replace the rear compartment lid latch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Compartment Courtesy Lamp Replacement
    •  Rear Compartment Lid Ajar Indicator Switch Replacement
    •  Control Module References for BCM replacement, setup, and programming