GM Service Manual Online
For 1990-2009 cars only

Power Door Latch System Components

    • Remote control door lock receiver (RCDLR)
    • Body control module (BCM)
    • Driver door module (DDM)
    • Passenger door module (PDM)
    • Driver exterior door handle switch
    • Driver door ajar switch
    • Driver door open switch
    • Driver interior door handle switch
    • Passenger exterior door handle switch
    • Passenger door ajar switch
    • Passenger door open switch
    • Passenger interior door handle switch
    • The ECM/TCM Fuse 11 15 Amp mini-fuse for the RCDLR
    • The BATT 3 Fuse 29 60 Amp mega-fuse for the BCM
    • The Door Controls 30 Amp circuit breaker for the DDM and PDM

Driver Power Door Latch Unlatch Operation

The remote control door lock receiver (RCDLR), driver door module (DDM) and body control module (BCM) control the output functions of the driver power door latch. These output functions allow the RCDLR and BCM to command the driver power door latch motor to Unlatch.

When the RCDLR receives an input from either the driver exterior door handle switch or driver interior door handle switch, it checks the Lock/Unlock status of the driver door. If the status of the driver door is Unlock, the RCDLR applies the ground for the driver power door latch.

At the same time that the RCDLR is receiving its input, the DDM is also receiving the same input. When the DDM receives its input from the door handle switch, it checks the window indexing status of the driver door. If the window is below the index point, it sends a serial data message to the BCM to apply voltage for the driver power door latch. If the window is above the index point, it will first index the window, then send a serial data message to the BCM to apply voltage for the driver power door latch. For a better description of window indexing, refer to Power Windows Description and Operation .

Passenger Power Door Latch Unlatch Operation

The remote control door lock receiver (RCDLR), passenger door module (PDM) and body control module (BCM) control the output functions of the passenger power door latch. These output functions allow the RCDLR and BCM to command the passenger power door latch motor to Unlatch.

When the RCDLR receives an input from either the passenger exterior door handle switch or passenger interior door handle switch, it checks the Lock/Unlock status of the passenger door. If the status of the passenger door is Unlock, the RCDLR applies the ground for the passenger power door latch.

At the same time that the RCDLR is receiving its input, the PDM is also receiving the same input. When the PDM receives its input from the door handle switch, it checks the window indexing status of the passenger door. If the window is below the index point, it sends a serial data message to the BCM to apply voltage for the passenger power door latch. If the window is above the index point, it will first index the window, then send a serial data message to the BCM to apply voltage for the passenger power door latch. For a better description of window indexing, refer to Power Windows Description and Operation .

Door Ajar Indicator

The body control module (BCM) receives a discrete input from the driver and passenger 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 BCM interprets this and communicates via Class 2 serial data with the instrument panel cluster (IPC). When a door is open/ajar and the vehicle is in any gear other than PARK, the driver information center (DIC) will display DOOR AJAR for the appropriate door that is opened. If the door is still ajar and the vehicles speed is greater than 4.8 km/h (3 mph) a chime will sound. The driver door latch assembly is grounded at G301 and the passenger door latch assembly is grounded at G302.