Vehicle Locking / Unlocking

To unlock, the SKREEM module sends a signal to the Body Control Module. The Body Control Module then sends a signal to the Central Locking Pump/Security System Module (CLP/SSM) via the Controller Area Network (CAN) Bus. The CLP/SSM pump motor starts running and supplies air pressure. The door lock actuators are pressurized. When a pressure threshold is reached in the system, the pump is switched off by an internal pressure switch. The pressure in the system is then released by the CLP/SSM and the unlocking operation is completed. The locking procedure is accomplished in a fashion opposite to the unlocking operation. However, the next time the remote control button is pressed, the CLP/SSM is also actuated by connecting it to ground by the second control lead on the SKREEM module. The direction of rotation for the CLP/SSM pump motor is reversed, thereby providing the vacuum required to lock. In order to avoid unlocking the vehicle unintentionally, the vehicle is relocked by the CLP/SSM via the SKREEM module. After unlocking with the remote control, the locks will be relocked if either door is not opened within 40 seconds, the key is not inserted into the ignition switch, or the interior power door lock switch is not actuated. The CLP/SSM reads the signals (door contacts, liftgate/decklid, interior power door lock switch) and actuates the power door lock actuators. The vehicle security alarm is also activated by the relocking function.