Locks: Description and Operation

Power Door Latch Description and Operation

Power Door Lock System Components

* Driver door lock/window switch

* Passenger door lock/window switch

* Driver interior door handle switch (Coupe)

* Driver exterior door handle switch

* Passenger interior door handle switch (Coupe)

* Passenger exterior door handle switch

* Left rear exterior door handle switch

* Right rear exterior door handle switch

* Body control module (BCM)

* Rear door lock relay (Sedan/Wagon)

* Rear door unlock relay (Sedan/Wagon)

* Deadbolt relay PCB

* Driver door latch

* Passenger door latch

* Left rear door latch (Sedan/Wagon)

* Right rear door latch (Sedan/Wagon)

* Remote control door lock receiver

* DOOR LOCK 15 amp mini-fuse

Power Door Lock and Unlock Switch Operation (Sedan/Wagon)

The driver and front passenger power door lock switches are integral components of the driver door lock/window switch and passenger door lock/window switch. 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 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 BCM. The driver door lock/window switch and passenger door lock/window switch 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.

Power Door Lock and Unlock Switch Operation (Coupe)

The driver and front passenger power door lock switches are integral components of the driver door lock/window switch and passenger door lock/window switch. The switches consist of 2 positions, LOCK and UNLOCK, and are in the normally open state. When placed in the LOCK position, the driver door lock/window switch and the passenger door lock/window switch will disable the interior and exterior door handle switches preventing the doors from being open. Pressing the UNLOCK position on either power door lock will enable the interior and exterior door handle switches providing normal door opening and closing operation.

Power Door Lock Deadlock Motors

Some vehicles may be equipped with the deadlock feature, which includes a reversible deadlock motor contained within each door latch assembly. Each deadlock motor is wired to the lock and unlock relays through 2 control circuits; the door lock actuator lock control circuit and the door lock actuator unlock control circuit. To deadlock a door, the door locks are activated by momentarily supplying voltage to the door lock actuator lock control circuits, and ground to the door lock actuator unlock control circuits. The voltage to the door lock actuators is provided through the normally open switch contacts of the theft deterrent alarm relay. To complete the deadlocking, the theft deterrent alarm momentarily energizes an internal relay causing the switch contacts to close applying voltage to the deadlock actuator control circuits for both front and rear doors. Ground to the deadlock actuators is provided through the door lock actuator unlock control circuits. Once the doors are deadlocked, the mechanical lock/unlock linkage within the door lock actuator is physically disconnected so that the door can not be opened even when manually unlocked. If the content theft feature is armed at the same time, the interior door lock switches will not operate the locks.

To undeadlock the doors, the BCM unlocks the doors by momentarily applying ground to the deadlock motor unlock control circuit. This energizes the rear door unlock relay coil causing voltage to flow through the switch contacts to the door lock and deadlock motors. Ground for both motors is supplied through the door lock motor lock circuit through the normally closed contacts of the lock relay to ground.

Driver Door Key Cylinder Switch

The vehicle may be equipped with the central door unlock feature. With this feature, all doors can be unlocked from the driver door using the door key. To operate the feature, the door key is inserted into the driver door lock cylinder, turned to the unlock position and held for 3 seconds or longer, or turned to the unlock position twice within 3 seconds. A mechanical linkage rod connects the driver door lock cylinder to the key cylinder unlock switch, which is built into the driver door latch assembly. The key cylinder unlock switch contacts, which are normally open, receive a constant ground via the ground circuit. When the door key is turned to unlock, the switch contacts close and the driver door lock/window switch detects a switched ground. The driver door lock/window switch sends a serial data to the Remote control door lock receiver, indicating the key cylinder unlock switch request. The remote control door lock receiver is the master of all lock and unlock operations. If the remote control door lock receiver determines that the key cylinder switch request is valid and conditions are correct, a serial data message will be sent to the driver door lock/window switch, passenger door lock/window switch, and BCM to lock or unlock there respective doors.

Passive Keyless Entry System Description and Operation

Passive keyless entry allows entry to a locked vehicle without pressing any buttons on the keyless entry transmitter. You must only have the transmitter with you. This passive system is also part of the vehicle starting system. It allows you to start and run the vehicle having only the transmitter as your key. The passive entry and starting system use low frequency antennas in several different areas on the vehicle to determine the location of the transmitter. When passively opening a locked door, trunk or the liftgate, you must have a programmed transmitter with you in your pocket, purse, or briefcase. As a customer opens the door handle or presses the trunk/liftgate touch pad, the low frequency antenna sends out a challenge to the keyless entry transmitter. The transmitter should be in a one meter range of the door or trunk/liftgate in order to receive the challenge. If the challenge is met, the transmitter will respond, allowing the door to be unlocked and opened by pulling the appropriate door handle or allowing the trunk/liftgate to open by pressing the touch pad.

Lockout Prevention

This feature prevents the locking of the driver door if the ignition key is left in the ignition lock cylinder. If a lock function occurs from any door lock switch and the BCM detects an active state on either the left front door latch signal, secondary door latch switch signal and/or the trunk ajar switch signal circuits and the key in ignition switch signal circuit is in the YES state, the BCM, driver door lock/window switch and passenger door lock/window switch will lock the doors and then the driver door lock/window switch will unlock the driver door.

Delayed Locking Operation

With any door open and a door lock switch is activated in the lock position, the driver door lock/window switch, passenger door lock/window switch and the BCM will go into a lock pending state. The BCM will also give 3 audible chimes. When the door is closed, the driver door lock/window switch, passenger door lock/window switch and the BCM will lock the doors after approximately 5 seconds. This feature can be overridden by activating the door lock switch a second time and the doors will lock even with a door open.

Door Ajar Indicator

The driver door lock/window switch and passenger door lock/window switch each receive a discrete input from there respective door ajar switch signal circuits. The BCM receives discrete inputs from each of the rear 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 door lock/window switches and/or BCM interprets this and communicates via serial 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.