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.

DTC Descriptor

DTC B2991 00: Passenger Door Ajar Circuit

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 driver and passenger jamb switches. 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 ajar indicator and also send a serial data massage to the radio to activate the door ajar audible warming when the transmission is removed from PARK and the vehicle speed is greater then 8 km/h (5 mph).

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 removing the ground to the BCM. The BCM sends a signal to the IPC to illuminate the door ajar indicator when a door is open.

Conditions for Running the DTC

The system voltage is 9-16 volts.

Conditions for Setting the DTC

The BCM detects a short to ground in the passenger door ajar circuit for longer than 10 minutes.

Action Taken When the DTC Sets

The door ajar indicator is illuminated at all times.

Conditions for Clearing the DTC

    • The DTC will be current for as long as the fault is present.
    • When the fault is no longer present, the DTC will become a history DTC.
    • A history DTC will clear after 50 ignition cycles.

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

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

Circuit/System Testing

  1. Ignition OFF, disconnect harness connector at the appropriate passenger door latch.
  2. Test for less than 10 ohms between the ground circuit terminal listed below and ground.
  3. • Passenger door latch terminal 3
    • Right rear door latch terminal 3
    • Left rear door latch terminal 6
    If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the Door Ajar indicator is not illuminated.
  5. If the indicator is illuminated, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the BCM.
    • Passenger door latch signal circuit terminal 1
    • Right rear door latch signal circuit terminal 1
    • Left rear door latch signal circuit terminal 4
  6. Install a 3A fused jumper wire between the signal circuit terminal listed below and ground. Verify that the Door Ajar indicator is illuminated.
  7. • Passenger door latch signal circuit terminal 1
    • Right rear door latch signal circuit terminal 1
    • Left rear door latch signal circuit terminal 4
    If the indicator is not illuminated, 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 circuit tests normal, test or replace the passenger door latch.

Component Testing

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