Power Lock System
Door locking function - The electric door locks are controlled by the Body Control Module (BCM). This locks and unlocks the doors on the basis of two control types: external and internal.
External controls
- The external door locking/unlocking commands can arrive from the following components:
- Closing/opening buttons on Radio Frequency (RF) remote controls of keys
- Key cylinder on driver door handle
- Passive Entry System.
The BCM receives the RF signals from the locking/unlocking buttons on the remote controls via an aerial. The movement of the key cylinder on the driver door handle is detected by a switch connected electrically to the BCM.
The internal door locking/unlocking commands can arrive from the following components:
- Buttons on driver door panel
- Buttons on passenger door panel.
- Car speed above 20 km/h (12 mph) (speed information for BCM via Controller Area Network (CAN)
- Door unlock request from Fire Prevention System (FPS).
In every ignition switch position (OFF, RUN, START) the BCM, before sending the door locking/unlocking command, checks the status of the doors (open or closed) through the switches in the locks.
Status of door status switches
-
- Driver side door switch: if the door is closed the switch is open; if the door is open the switch is closed.
- Passenger side door switch: if the door is closed the switch is open; if the door is open the switch is closed.
- Rear door switches: if the doors are closed the switches (left and right) are open; if the doors are open, the switches are closed.
- Liftgate switch: if the liftgate is closed, the switch is closed; if the liftgate is open, the switch is open.
- Hood switch: if the hood is open the switch is open; if the hood is closed the switch is closed. (There is only a hood switch if there is an alarm.)
System without Passive Entry - The BCMs on North America Free Trade Agreement (NAFTA) vehicles can manage door locking even if one or more doors are open. Door locking will not be carried out only if the key is in the ignition switch. The BCMs on Europe Middle East Africa (EMEA) vehicles cannot manage door locking if one or more doors are open.
System with Passive Entry - Where there is the passive entry system, the doors can be locked centrally even if one or more doors are open. When the last door is closed, the BCM will request that the RH module locates the keys: if these are outside of the vehicle, the doors will maintain "locked" status. If, on the other hand, they are inside the vehicle, the BCM will centrally unlock the doors. EMEA vehicles may have electric locks with deadlocking. It is not available for NAFTA vehicles.
Electric locks - Inside the electric locks is a Positive Temperature Coefficient (PTC) element in series with their electric motors. The PTC elements permits thermal protection in the event that the BCM continues to supply current to the motors due to a fault. The resistance of the PTC element increases as its temperature increases, consequently interrupting the electrical circuit.