GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 DTS 🢒 Body 🢒 Body Rear End 🢒 Trunk Ajar Indicator Malfunction

Diagnostic Fault Information

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

The body control module (BCM) uses the rear compartment lid latch to determine the position of the trunk lid. When the lid is open, the rear compartment lid ajar switch is closed, providing a ground path for the trunk ajar switch signal circuit. When the BCM sees the trunk lid ajar, a serial data message is sent to the driver information center (DIC) requesting the Trunk Ajar message be displayed.

Reference Information

Schematic Reference

Body Rear End Schematics

Connector End View Reference

Body Rear End Connector End Views

Description and Operation

Luggage Compartment Description and Operation

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

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the rear compartment lid latch.
  2. Test for less than 1.0 ohm of resistance between the ground circuit terminal 3 and ground.
    3. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the Trunk Ajar message on the DIC is not displayed.
    4. ⇒If the Trunk ajar message is displayed, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.
  4. Install a 3-amp fused jumper between the signal circuit terminal 1 and ground. Verify the Trunk Ajar message is displayed on the DIC.
    5. ⇒If the Trunk Ajar message is not displayed, test the signal circuit terminal 1 for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.
  5. If all circuits test normal, test or replace the rear compartment lid latch.

Component Testing

Rear Compartment Lid Latch

  1. Ignition OFF, disconnect the harness connector at the rear compartment lid latch.
  2. Test for infinite resistance between the signal terminal 1 and the ground circuit terminal 3 in the open position.
    3. ⇒If not the specified value, replace the rear compartment lid latch.
  3. Test for less than 2.0 ohms of resistance between the signal terminal 1 and the ground circuit terminal 3 in the closed position.
    4. ⇒If greater than the specified range, replace the rear compartment lid latch.

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.