Power Locks: Description and Operation
INTRODUCTIONAll doors can be locked or unlocked electrically by operating the switch on either front door panels.
The rear doors can be locked or unlocked by actuation of the front door switch, or can be locked or unlocked mechanically and independently with their respective locking knobs.
The front doors can be locked or unlocked mechanically with the locking knob regardless of electrical locking and unlocking actuation with the front door knobs.
The right and left front door on all vehicles can be locked or unlocked mechanically from the outside with the key or electrically as described above. the left front can also be unlocked by actuation of the inside remote door handle. the right front door can be unlocked by actuation of the inside remote door handle.
SYSTEM OPERATION
Automatic Door Locks
The system includes an automatic door locking feature actuated by the Body Control Module (BCM). The vehicle is built with the system disabled.
When the system is disabled the door locks will work by use of the door lock switches only. when this system is enabled the automatic door locks will work automatically
The Body Control Module Controls the power locks when the 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. also, the BCM will automatically lock all doors when all of the conditions below are met:
- All doors are closed
- The vehicle speed exceeds 15 ± 1 M.P.H.
- The Throttle Position Sensor Tip-in Is Greater Than 10 ± 2 degrees
The Scan Tool (DRB) must be used to enable/disable the automatic door lock system. refer to the scan tool (DRB) for the procedure.
The body control module 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 latches are also equipped with a thermal protection system which prevents the latches from burning out.
Central Locking System
The central locking system is part of the vehicle theft security system. 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 key in the driver's door to the unlock position once will unlock driver's door only turning the key a second time to the unlock position within five seconds of the first time will unlock all doors. turn key once in the passenger's door to the unlock position will unlock all doors.
The Lock/unlock Operation Will Arm/disarm The Vehicle Theft Security System 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
With The key in the ignition switch in the on or off position and the driver's door open the BCM will ignore the command to lock the power door locks. once the key is removed, or the driver's door is closed, the body control module will allow the power door locks to lock.
When the Key-In switch is CLOSED (circuit G26 connected to circuit Z1) the Body Control Module (BCM) ignores the operators request for power door lock operation.
Keyless Entry System
The system allows locking and unlocking of vehicle door(s) by remote control using a hand held radio transmitter.
CIRCUIT OPERATION
The power door lock system is controlled by the Body Control Module (BCM). The door lock switches, located in the front doors, are supplied power on the M1 circuit. This circuit is the Ignition-Off Draw (IOD) circuit. It is protected by a 10 amp fuse located in cavity 5 of the junction block.
Both switches have a Light Emitting Diode (LED) located internal to the switch for night illumination. Power for the LED's is supplied on circuit F20. The F20 circuit is protected by a 15 amp fuse located in cavity 4-of the junction block. Power for the fuse is supplied on circuit A22. The A22 circuit connects to the ignition switch and is HOT in the RUN position only.
Circuit A22 is powered by circuit A2 from the PDC. This circuit is protected by a 40 amp fuse located in cavity 16 of the PDC. Ground for the LED's is supplied on circuit Z1 and terminates at the instrument panel left side cowl.
Power for the door lock motors is supplied to the BCM on circuit F135. This circuit is protected by a 15 amp fuse located in cavity 9 of the junction block. Circuit A3 is used to supply power to the fuse.
Circuit A3 is HOT at all times and is protected by a 40 amp fuse located in cavity 15 of the PDC. This circuit also supplies power for the Power Seat circuit breaker, and the Headlamp Delay Relay.