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

Left Front Door Ajar Switch Signal

2

1

1

--

Left Rear Door Ajar Switch Signal

2

1

1

--

Right Front Door Ajar Switch Signal

2

1

1

--

Right Rear Door Ajar Switch Signal

2

1

1

--

Driver Door Latch Ground

--

1

--

--

Passenger Door Latch Ground

--

1

--

--

Left Rear Door Latch Ground

--

1

--

--

Right Rear Door Latch Ground

--

1

--

--

1. Ajar Indicator Always Illuminated

2. Ajar Indicator Inoperative

Circuit/System Description

The driver door module (DDM) and passenger door module (PDM) each receive a discrete input from there respective door ajar switch signal circuits. The body control module (BCM) receives discrete inputs from each of the rear door ajar switch signal circuits. The door ajar switches are integral to each door latch assembly. When a door is opened, the normally open door ajar switch closes. With the door ajar switch closed, ground is provided to the door ajar switch signal circuit. The door modules and/or BCM interprets this and communicates via serial data with the instrument panel cluster (IPC).

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Latch 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 Active and Inactive.
  2. If the value does not change, refer to Driver Door Ajar Switch Malfunction
  3. Observe the scan tool Passenger Door Ajar Sw. parameter while opening and closing the front passenger door. The parameter should change between Active and Inactive.
  4. If the value does not change, refer to Passenger Door Ajar Switch Malfunction.
  5. Observe the scan tool Left Rear Door Ajar Sw. and Right Rear Door Ajar Sw. parameters while opening and closing the left and right rear doors. The parameters should change between Door Closed and Door Ajar.
  6. If the appropriate value does not change, refer to Rear Door Ajar Switch Malfunction.

Circuit/System Testing

Driver Door Ajar Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the driver door latch.
  2. Test for less than 10 ohms between the ground circuit terminal 8 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 Inactive.
  5. If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the DDM.
  6. Install a 3A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool Driver Door Ajar Sw parameter is Active.
  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 DDM.
  8. If all circuits test normal, test or replace the driver door latch.

Passenger Door Ajar Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the passenger door latch.
  2. Test for less than 10 ohms between the ground circuit terminal 3 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 Passenger Door Ajar Sw parameter is Inactive.
  5. If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the PDM.
  6. Install a 3A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool Passenger Door Ajar Sw parameter is Active.
  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 PDM.
  8. If all circuits test normal, test or replace the passenger door latch.

Rear Door Ajar Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the appropriate rear door latch.
  2. Test for less than 10 ohms 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
    If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify the appropriate scan tool Rear 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 signal circuit terminal 4
    • Right rear door ajar switch signal circuit terminal 1
  6. Install a 3A fused jumper wire between the signal circuit terminal listed below and ground. Verify the scan tool Rear Door Ajar Sw parameter is Door Ajar.
  7. • Left rear door ajar switch signal circuit terminal 4
    • Right rear door ajar switch signal circuit terminal 1
    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 tests 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 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
    • 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
    • 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, DDM, PDM or DIC replacement, setup and programming