Power Door Locks

The BCM controls the door locks by using a series of 3 integral relays. A driver door unlock relay that is energized to unlock the driver door, a passenger door unlock relay that is energized to unlock the 3 passenger doors, and an all lock relay that is energized to lock all 4 doors. When the relays are not energized, ground is provided on both circuits to the lock motors within the latches. When an unlock relay energizes, voltage is provided to one side of the lock motor to unlock the door(s). When the lock relay energizes, the polarity is reversed and the motors lock the doors.

The BCM sends voltage signals to the door lock control switches. When a door lock control switch is pressed, the voltage signal is routed to ground, indicating a request to lock/unlock the doors.

The BCM also monitors the door lock/unlock status by sending a voltage signal to the lock/unlock feedback switch inside each of the 4 door latches. The switches are closed when the door is unlocked and open when locked. The BCM uses the input from the lock/unlock feedback switches to determine if the indicator should be illuminated or off. The BCM controls the voltage to the door lock indicator.

If all 4 doors are locked, the indicators are illuminated. If any door is unlocked, the indicators are off.

When locking the driver door using the door key cylinder, all the doors lock. When unlocking the driver door using the door key cylinder, only the driver door is unlocked.

In the event of a failure of the power door locks, the doors can be individually locked through the manual door lock. The manual door lock is located on the rear edge of the door just above the door latch opening. For the doors on the driver side of the vehicle, insert a key and turn the key clockwise to lock. For the doors on the passenger side of the vehicle, insert a key and turn the key counterclockwise to lock.

Based upon input from the door lock control switches, the lock/unlock feedback switches and the RKE transmitter, the BCM energizes the lock all relay, the unlock driver door relay or unlock all relay.