Principles of Operation (How Does It Work?)

The Rear Electronics Module (REM) controls the output functions of the door locks for the following:
^ Passenger front door lock actuator
^ Passenger rear door lock actuator
^ Driver rear door lock actuator

The REM controls the input functions of the door locks for the:
^ Passenger door lock and unlock switch

The Driver Door Module (DDM) controls the output functions of the door locks for the:
^ Driver door lock actuator

The DDM controls the input functions of the door locks for the:
^ Driver door lock and unlock switch

Operating commands for the passenger front, passenger rear and driver rear lock actuators are received in two forms: the Standard Corporate Protocol (SCP) communication network from the DDM or directly from the passenger door lock and unlock switch, which is hardwired to the REM. The driver door lock and unlock switch is hardwired to the DDM. When the driver switch is activated, the DDM will activate the driver door lock actuator and also sends a message through the SCP network. In turn, the REM will output the desired command to the appropriate lock actuators. When the passenger door lock and unlock switch is activated, the REM will activate the lock actuators, which it controls, and it will also send a message through the SCP network to the DDM to activate the driver door lock actuator.

Operating commands for the driver actuator are received in two forms: through the SCP communication network from the REM or directly from the driver door lock and unlock switch, which is hardwired to the DDM. The passenger door lock and unlock switch is hardwired to the REM. When the passenger switch is activated, the REM will activate the passenger front, passenger rear, and driver rear door lock actuators and also send a message through the SCP network. In turn, the DDM will output the desired command to the driver front door lock actuator. When the driver door lock and unlock switch is activated, the DDM will activate the driver lock actuator, which it controls, and it will also send a message through the SCP network to the REM to activate the appropriate door lock actuators.

Operating commands for the luggage compartment release lock motor are received in two forms: directly from the luggage compartment release switch which is hardwired to the REM, or through the SCP network from the DDM. When the luggage compartment release switch is activated , the REM will activate the luggage compartment lock actuator, which is hardwired to the REM. The luggage compartment unlock operation is also possible when activated from the remote transmitter through the DDM, with the DDM sending a message over the SCP network. The REM will then activate the luggage compartment release motor.

The DDM receives inputs from the remote transmitter(s) and delivers outputs enabling the driver to lock and unlock the vehicle's power lock system, or to arm and disarm the perimeter alarm. The DDM can be programmed to accept up to four transmitter ID codes from four remote transmitters.

Remote locking and unlocking of the doors is accomplished by the DDM receiving a command message from the remote transmitter. The DDM then processes the command and sends a signal directly to the driver door lock actuator, and sends a message through the SCP network, to the REM which will drive the appropriate passenger door lock actuators. Fault management will disable the remote locking and unlocking feature in the event of an ignition switch or PRNDL invalid or missing message to the front electronic module.

All power door locks and the luggage compartment release motor are powered by the Switched System Power (SSP) feature. A failure of any or all of the SSP features could cause inoperative power door locks. When diagnosing power door locks, it is essential to determine if all the related symptoms and DTCs are controlled by the SSP feature.