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

1

2

--

--

Left Rear Door Ajar Signal

1

2

--

--

Passenger Door Ajar Signal

1

2

--

--

Right Rear Door Ajar Signal

1

2

--

--

Driver Door Latch Low Reference

--

2

--

--

Passenger Door Latch Low Reference

--

2

--

--

Left Rear Door Latch Ground

--

2

--

--

Right Rear Door Latch Ground

--

2

--

--

1. Door ajar message always displayed

2. Door ajar message inoperative

Circuit/System Description

The driver door module (DDM) and the passenger door module (PDM) receive a discreet input from the driver door ajar switch and the passenger door ajar switch respectively. Likewise, the body control module (BCM) receives a discrete input from both the left and right rear door ajar switches. The door ajar switches are normally open when the doors are fully closed. When a door is open, the door ajar switch contacts close providing a path to ground. The driver information center (DIC) displays the appropriate door open message when one of the doors is open. The instrument panel cluster (IPC) receives a serial data message from either the BCM, DDM or PDM indicating the door ajar status.

Reference Information

Schematic Reference

Interior Lights 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

  1. Ignition ON, all doors closed, observe the scan tool Driver Door Module Door Ajar Sw parameter and Passenger Door Module Door Ajar Sw parameters while opening and closing the driver door and passenger door. The parameter should change between On and Off.
  2. If the parameter does not change, refer to Front Door Ajar Malfunction.
  3. Observe the scan tool Left Rear Door Ajar Sw. parameter and Right Rear Door Ajar Sw. parameter while opening and closing the rear doors. The parameter should change between On and Off.
  4. If the parameter does not change, refer to Rear Door Ajar Malfunction.
  5. If the scan tool parameters function normally replace the IPC.

Circuit/System Testing

Front Door Ajar Switch Circuit Test

  1. Ignition OFF, disconnect the X1 harness connector at the appropriate door latch.
  2. Test for less than 5 ohms between the low reference circuit terminal listed below and ground.
  3. • Driver door latch low reference circuit terminal D
    • Passenger door latch low reference circuit terminal A
    If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal replace the door module.
  4. Ignition ON, verify the scan tool Door Ajar Sw parameter is Off.
  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 door module.
    • Driver door latch signal circuit terminal B
    • Passenger door latch signal circuit terminal C
  6. Install a 3A fused jumper wire between the signal circuit terminal and listed below and ground. Verify the scan tool Door Ajar Sw parameter is On.
  7. • Driver door latch signal circuit terminal B
    • Passenger door latch signal circuit terminal C
    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 affected door module.
  8. If all circuits test normal, test or replace the door latch.

Rear Door Ajar Switch Circuit Test

  1. Ignition OFF, disconnect the X1 harness connector at the appropriate rear door latch.
  2. Test for less than 1 ohm between the ground circuit terminal listed below and ground.
  3. • Left rear door latch ground circuit terminal D
    • Right rear door latch ground circuit terminal A
    If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the scan tool Left Rear Door Ajar Sw parameter or Right Rear Door Ajar Sw. parameter is Off.
  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 termina B
    • Right rear door latch signal circuit terminal C
  6. Install a 3A fused jumper wire between the signal circuit terminal listed below and ground. Verify the scan tool Left Rear Door Ajar Sw parameter or Right Rear Door Ajar Sw. parameter is On.
  7. • Left rear door latch signal circuit terminal B
    • Right rear door latch signal circuit terminal C
    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 rear 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 B and low reference terminal D
    • Left rear door latch signal terminal B and ground terminal D
    • Right rear door latch signal terminal C and ground terminal A
    • Passenger door latch signal terminal C and low reference terminal A
    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 B and low reference terminal D
    • Left rear door latch signal terminal B and ground terminal D
    • Right rear door latch signal terminal C and ground terminal A
    • Passenger door latch signal terminal C and low reference terminal A
    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, DDM, PDM, or IPC replacement, programming, and setup