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

Driver Door Ajar Signal

B2976 00

1

1

--

Passenger Door Ajar Signal

B2991 00

1

1

--

Driver Door Latch Ground

--

1

1

--

Passenger Door Latch Ground

--

1

1

--

1. Door Ajar Indicator Inoperative

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 km/h (5 mph).

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Locks 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 Verification

  1. Ignition ON, observe the scan tool Driver Door Ajar Sw parameter while opening and closing the driver door. The parameter should change between Door Closed and Door Ajar
  2. If the parameter does not change, refer to Driver Door Ajar Malfunction.
  3. With the passenger doors closed, observe the scan tool Passenger Door Ajar Sw. parameter while opening and closing each door. The parameter should change between Door Closed and Door Ajar.
  4. If the parameter does not change, refer to Passenger Door Ajar Malfunction.

Circuit/System Testing

Driver Door Ajar Malfunction

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

Passenger Door Ajar Malfunction

  1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
  2. Test for less than 1 ohm between the ground circuit terminal listed below and ground:
  3. • Left rear door ajar switch ground circuit terminal 6
    • Front passenger door ajar switch ground circuit terminal 3
    • Right rear door ajar switch ground circuit terminal 3
    If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Passenger Door Ajar Sw. parameter is Door Closed.
  5. If not the specified value, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the BCM.
    • Left rear door ajar switch ground circuit terminal 4
    • Right rear door latch signal circuit terminal 4
    • Front passenger door latch signal circuit terminal 1
  6. Install a 3A fused jumper wire between the signal circuit terminal and the ground circuit terminal listed below. Verify the scan tool Passenger Door Ajar Sw. parameter is Door Ajar.
  7. • Left rear door latch signal circuit terminal 4 and ground circuit terminal 6
    • Right rear door latch signal circuit terminal 4 and ground circuit terminal 3
    • Front passenger door latch signal circuit terminal 1 and ground circuit terminal 3
    If not the specified value, test the 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 door latch.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
  2. With the switch in the open position, test for infinite resistance between the signal and the ground terminals listed below:
  3. • Driver door latch signal terminal 4 and ground terminal 6
    • Left rear door latch signal terminal 4 and ground terminal 6
    • Right rear door latch signal terminal 4 and ground terminal 3
    • Front passenger door latch signal terminal 1 and ground terminal 3
    If not the specified value, replace the door latch.
  4. With the switch in the closed position, test for less than 2 ohms between the signal and the ground terminals listed below:
  5. • Driver door latch signal terminal 4 and ground terminal 6
    • Left rear door latch signal terminal 4 and ground terminal 6
    • Right rear door latch signal terminal 4 and ground terminal 3
    • Front passenger door latch signal terminal 1 and ground terminal 3
    If greater than the specified range, replace the door latch.

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 BCM replacement, setup, and programming