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

Deadbolt Lock Control

1

1

1

--

Deadbolt Unlock Control

1

1

1

--

1. Power Door Locks Deadbolt Malfunction

Circuit/System Description

Export vehicles may be equipped with the deadbolt feature, which includes a reversible deadbolt motor contained within each door latch assembly. Each deadbolt motor is wired to the driver door module (DDM) through 2 circuits; the deadbolt lock control circuit and the deadbolt unlock control circuit. To deadbolt a door, the body control module (BCM) locks the door by momentarily applying voltage to the door latch motor control circuit. The remote control door lock receiver (RCDLR) applies ground to the door latch enable control circuit to complete the circuit to the door latch motor. To complete the deadbolting, the DDM momentarily applies voltage to the deadbolt lock control circuit and ground to the deadbolt unlock control circuit. If the content theft feature is armed at the same time, the interior door lock switches will not operate the locks.

To undeadbolt the door, the DDM reverses the polarity, applying battery voltage to the deadbolt unlock control circuit, and ground to the deadbolt lock control circuit.

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

Ignition ON, command the Door Deadbolt Lock/Unlock ON and OFF with a scan tool. The deadbolts should perform the LOCK and UNLOCK functions.

Circuit/System Testing

Deadbolt System Inoperative One Door

  1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
  2. Connect a test lamp between control circuit terminals listed below:
  3. • Driver door latch control circuit terminal 1 and control circuit terminal 2
    • Passenger door latch control circuit terminal 6 and control circuit terminal 7
  4. Command the Door Deadbolt Lock/Unlock ON and OFF with a scan tool with a scan tool. The test lamp should illuminate when commanding the LOCK and UNLOCK states.
  5. If the test lamp remains OFF during either of the commands, test either control circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the DDM.
    If the test lamp is always ON, test either control circuit for a short to voltage. If the circuits test normal, replace the DDM.
  6. 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. Install a 15A fused jumper wire between the control terminal listed below and and 12 volts.
  3. • Driver door latch control terminal 1
    • Passenger door latch control terminal 6
  4. Momentarily install a jumper wire between the control terminal listed below and ground. The door latch should perform the LOCK or UNLOCK function
  5. • Driver door latch control terminal 2
    • Passenger door latch control terminal 7
    If the function does not perform as specified, replace the door latch.
  6. Reverse the jumper wires; the door lock actuator should perform the UNLOCK or LOCK function.
  7. If the function does not perform as specified, replace the door latch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Door Lock Replacement
    •  Control Module References for DDM replacement, setup, and programming