Central locking

The central locking is controlled by the general module and the door module in the driver's and front passenger's doors.

The central locking drives in the vehicle doors are integrated in the system lock and facilitate locking, arming and unlocking of the doors.

The fuel filler flap is also locked and unlocked by a drive mechanism.

Functions

General

A differentiation is made between locking and locking with arming with regard to the functions of the central locking system.

Locking without arming: The vehicle doors can be opened from the inside by pulling the door handle twice.

Locking with arming: The vehicle doors can be opened neither from the inside nor the inside.

”Locking with arming” is implemented when:

- Ignition lock is in position 0 and the vehicle key is removed
- The driver's or front passenger's door is opened after removing the key
- The driver's and front passenger's doors are closed
- The vehicle is locked via the door lock or remote control

The fuel filler flap is locked with the vehicle central arrest.

Central locking drives

The drives in the front doors are actuated by the door modules. The rear door drives and fuel filler flap drive are actuated by the general module.

A repeat inhibit function is provided to protect the drives from thermal overload as the result of frequent use.

Fuel filler flap

A differentiation is made between two types of fuel filler flap drive:
- Activation of the central locking drive for the fuel filler flap together with the rear doors directly via the general module. The fuel filler flap is locked when the doors are locked, i.e. also when the vehicle is locked by means of the centerlock button.
- Activation of the central locking drive for the fuel filler flap by means of an additional external relay. The fuel filler flap is only locked when the vehicle is armed. This version is fitted in US vehicles.

Operating points

The central locking system can be operated from following points:

- Door lock of driver's door
- Remote control (country-specific radio or infrared remote control)
- Centerlock button (central locking button) in vehicle

The vehicle can only be locked and unlocked with the Centerlock button, i.e. not armed and disarmed. The fuel filler flap is also not locked.

Note: Remote control functions are executed only if there is no key inserted in the ignition lock.

Automatic unlock

The vehicle doors are unlocked automatically when the airbag control unit detects a crash. Crash signalling is performed via the K bus. After crash detection, the central locking system must be unlocked once before locking is possible again.

An armed vehicle is disarmed automatically (not unlocked) when the vehicle key is inserted in the ignition lock. This status is detected by the control unit of the ”electronic vehicle immobilisation system (EWS)”.

Selective release

The following function can be coded via car memory or is coded as standard in some country-specific variants (e.g. USA):

Initially only the driver's door is unlocked if a locked vehicle is unlocked by means of the door lock or remote control. All other doors are switched from the armed status to the disarmed status, however, they are not unlocked (it is possible to unlock the doors via the inner door handle or Centerlock button). The doors are unlocked when the vehicle is unlocked for a second time via the door lock or remote control.

Automatic lock

The following function can be coded via car memory or is coded as standard in some country-specific variants (e.g. USA):

The doors are locked automatically on exceeding a driving speed of 8 km/h.

Emergency operation

In the event of electrical operation failing (e.g. discharged batteries) the door can be unlocked mechanically via the door lock.

Boot lid

Operation of the upper tailgate depends on the status of the central locking system.

When the vehicle is locked, the upper tailgate can only be unlocked by means of the pushbutton in the switch centre of the centre console.

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