Power Locks: Description and Operation
POWER DOORPower Door Locks
All doors can be locked or unlocked electrically by operating the switch on either front door panels. When the door lock switch is activated the Body Control Module (BCM) actuates the door lock relay.
All doors can be locked or unlocked mechanically and independently with their respective locking knobs.
The right and left front door can be locked or unlocked mechanically from the outside with the key or all locks can be remotely locked or unlocked with the Remote Keyless Entry (RKE) transmitter. All doors can be locked/unlocked from the front doors via the Central Locking System. The front doors can also be unlocked by actuation of the inside remote door handle.
The deck lid can be unlatched by either depressing the push switch from inside the car, manually by key from outside or by depressing the remote keyless entry deck lid release button two times. This feature is customer programmable. The customer has a choice of one or two button presses for deck lid opening. The vehicle is shipped in the button pressed twice mode.
NOTE: The Power Door Lock Motor is not serviced separately. It is part of the door latch assembly. Refer to Body, Door - Front, Front Door Latch, or Body, Door - Rear, Rear Door Latch, Removal and Installation.
The Body Control Module (BCM) actuates the power door lock relays when a door lock switch is activated. If the door lock switch is pressed for longer than eight consecutive seconds, the BCM will de-energize the door lock relay.
The system includes an Automatic Door Locking feature. The vehicle is shipped with the system enabled. When the system is disabled the door locks will work by use of the door lock switches and the Remote Keyless Entry System only. When the Automatic Door Lock System is enabled the BCM will automatically lock all the doors when all of the conditions below are met:
- All doors are closed.
- The vehicle speed exceeds 15 ± 1 mph.
- The throttle position sensor tip-in is greater than 10 ± 2 degrees.
The DRB III scan tool is used to enable/disable the automatic door lock system. Refer to the proper Body Diagnostic Procedures. They are also customer programmable. Refer to Owners Manual for customer programming procedures.
The BCM will automatically re-lock all doors if the above conditions are met and if any of the doors become ajar and then closes again.
The power lock motors are also equipped with a thermal protection system which prevents the motors from burning out. The motors may chatter if they are continuously activated.
Central Locking
The Central Locking System is part of the Vehicle Theft Security System (VTSS).
Using the key, turn the driver's or passenger door cylinder lock to the lock position, all doors will lock. This feature operates differently on each door. Turn the key in the driver's door to the unlock position once will unlock the driver's door only. Turning the key a second time to the unlock position within five seconds of the first time will unlock all the doors. Turn the key once in the passenger's door to the unlock position will unlock all doors.
The lock/unlock operation will arm/disarm the VTSS and will also activate/cancel the illuminated entry feature.
Child Protection Lock
The child protection locks are on the rear doors only.
The lock when engaged, will disable the inside door handle from opening the door. The lock is part of the latch/lock assembly. The lock is engaged by moving a lever that is located on the rearward inside edge of the door.
Door Lock Inhibit
The Door Lock Inhibit prevents the vehicle from being locked with the key in the ignition.
With the key in the ignition switch and the driver's door open, the Body Control Module (BCM) will ignore the command to lock the power door locks.
Once the key is removed, or the driver's door is closed, the BCM will allow the power door locks to lock.
Fig.1 Remote Keyless Entry Transmitter:
Remote Keyless Entry
The system allows locking and unlocking of vehicle door(s), deck lid release, and panic by remote control using a hand held radio frequency transmitter. The vehicle must be in PARK before the trunk lid can be unlatched with the transmitter.
The receiver may receive signals from up to four transmitters. Each transmitter has its own code, and the code is programmed and stored into receiver memory. If a transmitter is replaced or additional transmitters are added, the codes for all units have to be reprogrammed into the receiver memory. If a receiver module is replaced, the transmitter codes must be stored in the new receiver memory.
The transmitter has four buttons for operation. They are LOCK, UNLOCK, DECK LID RELEASE, and PANIC.
- The UNLOCK button will unlock the driver's door and enable illuminated entry Pushing and releasing the button once will unlock the driver's door. Pushing and releasing the button two times, within a five second interval, will unlock all doors.
- Upon pressing the LOCK button, the horn will sound a short CHIRP (if enabled) and flash the park lamps to notice that the all door lock signal was received and set. Illuminated entry is cancelled and the interior lamps are faded to OFF.
- Pushing and releasing the DECK LID RELEASE button (one or two times depending on customer preference) within a two second interval, will slightly ajar the deck lid.
- Pushing and holding the PANIC button will cause the panic alarm to sound for three minutes, until the panic button is pressed and held a second time, or the vehicle reaches a speed of 15 mph.
The receiver is capable of retaining a Vehicle Access Code (VAC) even when power is removed.
Each Remote Keyless Entry (RKE) module must have at least one and no more than four transmitters.
Horn Chirp Toggle
Once the transmitters have been programmed, the horn chirp can be enabled/disabled by sending the horn chirp toggle operation code to the Body Control Module (BCM).
This can be done using a DRB III scan tool or by the customer. The horn chirp will enter the opposite state of its current programmed state by receiving this operation code. The BCM is responsible for keeping track of the horn chirp status.