The driver and front passenger power door lock switches are integral components of the driver door module (DDM) and passenger door module (PDM). The switches consist of 2 positions, lock and unlock, and are in the normally open state. When placed in either the lock or unlock positions, the switches provide a direct input to there respective door control module. When a power door lock switch is operated to the lock or unlock position, the associated door control module responds by sending a GMLAN serial data message indicating a change in the switch's position. This serial data message is received by the opposite door control module as well as the body control module (BCM). The DDM and PDM respond to the lock/unlock request by activating there associated power door lock motors to the appropriate direction to lock or unlock the front doors. The BCM is responsible for controlling the left and right rear passenger door lock motors. The BCM, upon receipt of a lock or unlock serial data signal, will control either the rear door lock or unlock relay. When the appropriate door lock relay is energized, the rear power door lock motors will lock or unlock the rear doors.

Battery voltage must be between 9-16 volts.

DTC B3225 00 will set when the DDM detects a short to voltage, short to ground, or an open/high resistance in the driver door lock actuator lock control circuit.

The DDM will disable all lock requests.

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Vehicle Access Connector End Views

Electrical Information Reference

Scan Tool Reference

1. Ignition OFF, disconnect the harness connector at the driver door latch assembly.
2. Test for less than 5.0 ohms of resistance between the lock control circuit terminal 3 and ground.

⇒	If greater than the specified range, test the lock control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the DDM.

3. Test for less than 5.0 ohms of resistance between the unlock control circuit terminal 2 and ground.

⇒	If greater than the specified range, test the unlock control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the DDM.

4. Connect a test lamp between the lock control circuit terminal 3 and unlock control circuit terminal 2.
5. Perform the DOOR LOCK/UNLOCK test with a scan tool. The test lamp should turn ON when performing the DOOR LOCK/UNLOCK test.

⇒	If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the DDM.

6. If the circuits test normal, test or replace the driver door latch assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.