Handles, Locks, Latches and Entry Systems - System Operation and Component Description

IPC Module Network Input Messages

Power Door Locks

The BCM controls the door locks using a series of integrated relays (driver door unlock/passenger doors unlock/all doors lock). 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.

For vehicles not equipped with a memory seat, 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. When the BCM detects a lock or unlock request, the BCM energizes the appropriate relays to lock or unlock the doors.

For vehicles equipped with a memory seat, the DDM and PDM send 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. When the DDM or PDM detects a lock or unlock request, a message is sent over the CAN to the BCM to lock or unlock the doors.

In the event of a power door lock failure, the doors can be individually locked using 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 left door, insert a key and turn clockwise to lock. For the right door, insert a key and turn counterclockwise to lock.

Based on input from the door lock control switches, the passive entry system and the RKE transmitter, the BCM unlocks the driver door, unlocks all the doors or locks all the doors.

LED Door Lock Indicators

Each door panel has a door lock indicator located on the window sill to indicate the lock or unlock status of that individual door. The door lock indicators are controlled by the lock/unlock feedback switch located within each door latch. When powered, they illuminate to indicate a door is locked and are off when a door is unlocked.

The Light Emitting Diodes (LEDs) are powered continuously if the ignition is on, or for 5 minutes after a lock request if the ignition is off.

The LED door lock indicators brightness level works in conjunction with the backlighting brightness level setting.

For vehicles not equipped with a memory seat, the BCM provides voltage to the door lock indicators.

For vehicles equipped with a memory seat, the DDM and PDM provide voltage to their respective door lock indicator.

The lock/unlock feedback switch provides a ground path to bypass the indicator. The switch is closed when the door is unlocked (indicator not illuminated) and open when locked (indicator illuminated). The Body Control Module B (BCM-B) provides ground for the door lock indicators to illuminate.

The LED door lock indicators are part of the electrical harness and cannot be replaced independently.