The power door locks circuits use a door module in each door to control the power and ground to operate each doors lock. This has greatly reduced the physical amount of electrical wiring and harnesses needed to carry out the door lock functions. In order to control the door locks, the modules communicate with each other, and with other modules used throughout the vehicle via the Serial Data Class 2 communication line. Each door module controls the power and ground to each respective door lock actuator The rear integration (RIM) module is the lock master of the system.

The power door lock subsystem comprises the following components:

The rear integration (RIM) module is the door lock master device. This means the RIM has final control over whether or not all doors will lock or unlock under power. The RIM will not allow any doors to be power locked unless the key is out of the ignition and the doors are all closed as indicated by the door jamb switches.

The DDSA receives direct inputs from the driver's door lock switch, processes this information, and then sends a request message to the rear integration (RIM) module via the Serial Data Class 2 line. The RIM receives the request message and examines it for lockout prevention criteria. If the conditions are proper, the RIM sends a lock or unlock command message back to each of the door modules over the Serial data Class 2 line. The door modules also use the Serial Data Class 2 line to communicate with other vehicle system modules. Power to the DDSA is supplied directly by the drivers door module (DDM). Ground is supplied by a seperate circuit.

The driver door module (DDM) is wired to the the drivers door power door lock motor. Upon receipt of a lock or unlock request from the RIM over the Serial Data Class 2 line, the DDM applies voltage directly to the driver door lock motor to operate the lock or unlock function. Voltage of the correct polarity is applied to run the motor in one direction for the lock request, or, reversed to run the motor in the opposite direction for the unlock request. Battery voltage to the DDM is supplied through circuits wired to the circuit breakers located in the Rear Fuse (Bussed) Block.

The passenger's front door module (PFDM) is wired to the passenger front door power door lock motor. Upon receipt of a lock or unlock request from the RIM over the Serial Data Class 2 line, the PFDM applies voltage directly to the passenger's door lock motor circuits. Voltage of the correct polarity is applied to run the motor in one direction for the lock request, or, reversed to run the motor in the opposite direction for the unlock request. Battery voltage to the PFDM is supplied through circuits wired to the circuit breakers located in the Rear Fuse (Bussed) Block.

The rear door modules (RRDM) and (LRDM) control their respective rear door lock actuators. The RIM commands them to lock or unlock the doors via a Serial Data Class  2 line message. Voltage of the correct polarity is applied to run the associated motor in one direction for the lock request, or, reversed to run the associated motor in the opposite direction for the unlock request. Battery voltage is supplied to both rear door modules through circuits wired to the circuit breakers located in the Rear Fuse (Bussed) Block.

The middle door modules (LMDM) and (RMDM) control their respective rear door lock actuators. The RIM commands them to lock or unlock the doors via a Serial Data Class  2 line message. Voltage of the correct polarity is applied to run the associated motor in one direction for the lock request, or, reversed to run the associated motor in the opposite direction for the unlock request. Battery voltage is supplied to both middle door modules through circuits wired to the circuit breakers located in the Rear Fuse (Bussed) Block.

The drivers door power door lock switch is a multiplexed switch device that inputs directly to the driver's door switch assembly (DDSA), while the passenger door power door lock switches input directly to their associated door modules; the PFDM, LMDM, RMDM, LRDM, and RRDM. It must be noted that the rear doors do not have Unlock capability when operated from either rear door power lock switch.

The power door lock actuators receive their power from the door modules. The door modules apply battery voltage of the correct polarity to their respective door lock motors when any door lock switch is operated. This drives the door lock lever in or out in order to lock or unlock the door. The rear doors operate in the same way except they do not have Unlock capability when operated from the rear door lock switches. The power door lock switches are generally closed for just a moment. If the power door lock switches are held closed for too long, an electronic circuit breaker in each actuator will open to protect the motor against damage and a code will be set. The circuit breakers have positive temperature coefficients (PTC) and will reset automatically when voltage is removed from the actuator. When either the left or right front power door lock switch is activated, all of the doors are locked or unlocked in unison. When either the left or right rear power door lock switch is activated, all the doors can be locked in unison, but not unlocked. Each door lock actuator assembly contains a manual door lock lever. The driver door also has a Key Cylinder Unlock Switch wired directly to the driver door module that requests locking and unlocking functions from the RIM when activated. When the driver door key cylinder is turned counter clockwise and held in that position for longer than 3 seconds, all doors will unlock. Key locks and manual lock levers will still work if electrical power is lost.

The Serial Data Class 2 line is a serial data link. The serial data link replace cables in the vehicle by multiplexing (time-sharing) data to and from each device over a single wire referenced to ground. If the Serial Data Class 2 link is lost, both rear door modules, (RRDM) and (LRDM), and the passenger front door module (PFDM) enters the sleep mode. With the RRDM, the LRDM, and the PFDM in sleep mode, no power door lock operations are possible.

When the passenger front power door lock switch is pressed, the following events occur:

1. The passenger front door module (PFDM) will directly sense actuation of the passenger door power lock switch.
2. The PFDM will send a Serial Data Class 2 message to the rear integration module (RIM) requesting that the doors be locked.
3. The RIM receives the request message and examines for the following lockout prevention criteria:

•	IGNITION SWITCH KEY PRESENT from the ignition switch

•	DRIVER DOOR OPEN message from each of the door modules

4. The RIM broadcasts a serial data link command message to lock all of the doors when:

•	The ignition key is out of the ignition switch.

•	The driver's power door lock switch is held in the LOCK position for greater than 3 seconds (Lockout Override).

5. Each door module receives the command message from the RIM.
6. All four modules actuate their door lock motors, thus completing the locking sequence.