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

Door Ajar Signal Circuit

1

2

--

--

Door Ajar Ground Circuit

--

2

2

--

1. Door Ajar Light Stays On

2. Door Ajar Light Will Not Come On

Circuit/System Description

The body control module (BCM) receives a discrete input from the respective jamb switch to indicate the status of the door. The BCM then communicates this status to the instrument panel cluster (IPC) via a serial data message. The IPC, upon receipt of this serial data message, will illuminate the appropriate ajar message in the driver information center (DIC) and also send a serial data massage to the radio to activate the door ajar audible warning when the transmission is removed from PARK and the vehicle speed is greater then 8.05 km/h (5 mph).

Diagnostic Aids

The door ajar switches supply a ground to the BCM when the door is open. Once the door is closed the door ajar switch opens canceling the ground to the BCM. The BCM sends a signal to the IPC to turn on the door ajar light when a door is open.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

    •  Vehicle Access Connector End Views
    •  Data Communication 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

Circuit/System Verification

Ignition ON, observe the scan tool Door Ajar Sw parameter while opening and closing all doors. The reading should change between Door Ajar and Door Closed.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate door latch assembly.
  2. Test for less than 1 ohm of resistance between the appropriate door ajar switch ground circuit terminal H and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, doors closed, verify the scan tool Door Ajar Sw parameter for the appropriate door is Door Closed.
  5. If not the specified value, test the appropriate door ajar switch signal circuit for a short to ground. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the appropriate door ajar switch signal circuit terminal H and ground. Verify the scan tool Door Ajar Sw parameter is Door Ajar.
  7. If not the specified value, test the appropriate door ajar switch signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  8. If all circuits test normal, test or replace the appropriate door latch assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Front Side Door Latch Replacement
    •  Rear Side Door Latch Replacement
    •  Control Module References for IPC and BCM replacement, setup, and programming