Operation

OPERATION

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.

AUTOMATIC LOCKING / UNLOCKING

Upon reaching a speed of 15 km/h (9 MPH), the vehicle doors are locked automatically. The fuel tank flap remains unlocked. If, after automatic locking, the vehicle is unlocked with the interior power door lock switch, this state is maintained until a door is opened or until the ignition is switched off. Automatic locking is accomplished again only upon reaching the specified speed. The logic circuitry for this function is integrated into the CLP/SSM. The automatic locking function can be activated or deactivated with the DRB III(R). An alternative is to use the interior power door lock switch with the ignition switched on by pressing and holding the door lock switch for more than 5 seconds in either the lock (auto locking switched on) or unlock (auto locking switched off) position. The alternative of enabling/disabling the auto locking system by using the interior power door lock switch can also be inhibited with the DRB III(R).

EMERGENCY UNLOCKING

In the event of a vehicle collision, the doors are unlocked automatically by a crash sensor integrated into the CLP/SSM. The doors are unlocked after a delay time of 8 to 11 seconds. The emergency unlocking function interrupts all functions performed by the CLP/SSM, which are reactivated only after interrupting the ignition. The emergency unlocking function is only active when the vehicle is unlocked from the outside.

VEHICLE RELOCKING

In order to avoid unlocking the vehicle unintentionally, the vehicle is relocked by the CLP/SSM via the SKREEM module. Relocking is accomplished after unlocking with the remote control when: a door is not opened within 40 seconds, the key is not inserted into the ignition lock, or the interior power door lock switch is not actuated. The CLP/SSM reads the signals (door contacts, interior power door lock switch) and actuates the power door lock actuators. The vehicle security alarm is also activated by the relocking function.

ANTI-THEFT SYSTEM

Once the anti-theft alarm system is set, the anti-theft alarm can be triggered if:

- The Doors, Hood, or Liftgate/Decklid is opened
- The Radio is removed (disconnected electrically)
- The Ignition is jumped
- The Glove Box is opened
- The Anti-theft Tow Sensor is tripped
- The Alarm Siren is tripped

The inputs ready for triggering an alarm are checked twice per second by the CLP/SSM. If two sequential checks of the same input indicate that the input is not in the non-actuated state, the audible alarm Siren is triggered and the front and rear lamps flash.

SIREN

The vehicle theft system alarm Siren contains a built in rechargeable battery back up and can sound if its electrical circuits are disconnected or if the vehicle battery cables are disconnected. The Siren can also sound if the electrical circuits between it and the CLP/SSM are disconnected. Once triggered, the Siren can only be silenced by unlocking the vehicle with the RF key transmitter or by unlocking the vehicle with the mechanical key.

ANTI-THEFT SWITCH / ANTI-THEFT TOW SENSOR

The Anti-Theft Tow Sensor is an inclination sensor that contains electrodes which are partially immersed in an electrically conductive liquid. If the conductive value between the electrodes changes, the sensor recognizes a change in the inclination of the vehicle. When the vehicle is parked, the value for the vehicle position is stored. If the vehicle is moved with a certain inclination in longitudinal and/or lateral direction for a certain time when the anti-theft alarm system is activated, the Anti-Theft Tow Sensor transmits an alarm signal to the CLP/SSM. In order to allow the vehicle to be towed or transported without sounding the alarm Siren, the Anti-Theft Tow Sensor can be deactivated by pressing the Anti-Theft Switch which is located in the passenger compartment on the center console in front of the shift lever.