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 provide 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 Ajar Ground

--

1

1

--

Passenger Door Ajar Ground

--

1

1

--

1. Door Ajar Indicator Inoperative

Circuit/System Description

The body control module (BCM) receives a discrete input from the driver door ajar switch, the passenger door ajar switches, and the liftgate ajar switch. The door ajar switches are normally open when the doors are fully closed. When a door is opened, the door ajar switch contacts close providing a path to ground. The driver information center (DIC) located at the bottom of the instrument panel cluster (IPC), illuminates the appropriate door ajar message when one of the doors is open. The IPC receives a serial data message from the BCM indicating the door ajar status. If this message is displayed and the vehicle speed is greater than 8 km/h (5 mph), a chime will sound.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Door Ajar Indicator Description and Operation

Electrical Information Reference

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

Circuit/System Verification

Ignition ON, observe the door ajar indicator on the I/P while opening and closing each door. The indicator should turn ON and OFF when opening and closing each door.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
  2. Test for less than 1.0 ohm between the ground circuit terminal listed below and ground.
  3. • Left rear door latch ground circuit terminal 6
    • Right rear door latch ground circuit terminal 3
    • Driver door latch ground circuit terminal 8
    • Front passenger door latch ground circuit terminal 3
    If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the door ajar indicator on the I/P is not illuminated.
  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 latch signal circuit terminal 4
    • Right rear door latch signal circuit terminal 1
    • Driver door latch signal circuit terminal 6
    • 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 door ajar indicator on the I/P is illuminated.
  7. • Left rear door latch signal circuit terminal 4 and ground circuit terminal 6
    • Right rear door latch signal circuit terminal 1 and ground circuit terminal 3
    • Driver door latch signal circuit terminal 6 and ground circuit terminal 8
    • Front passenger door latch signal circuit terminal 1 and ground circuit terminal 3
    If not the specified value, test the appropriate 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 6 and ground terminal 8
    • Left rear door latch signal terminal 4 and ground terminal 6
    • Right rear door latch signal terminal 1 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 1 ohm between the signal and the ground terminals listed below:
  5. • Driver door latch signal terminal 6 and ground terminal 8
    • Left rear door latch signal terminal 4 and ground terminal 6
    • Right rear door latch signal terminal 1 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