Central Locking System

With the key in the driver's door or passenger's door, the central locking system can be actuated to lock and unlock all the doors of the car and the fuel filler flap.

Pin 4 of central locking system control module 175 is supplied with current via fuse 25.

With the ignition switch in the Drive position, pin 3 of the control module is supplied with current (+54 circuit) via fuse 20.

The control module is controlled from microswitch 274 in the driver's door, which attends to both locking and unlocking the central locking system.

When the car is locked from the passenger's door, microswitch 274 controls the central locking system control module.

When the car is unlocked from the passenger's door, locking mechanism 435 in the passenger's door controls the central locking system control module.

When the driver's door is locked, pin 2 of the control module is grounded and current is supplied to all actuating motors for 1 second via pin 7 of the control module, thus locking the doors.

When the passenger's door is locked, pin 5 of the control module is grounded and current is supplied to all actuating motors for 1 second via pin 7 of the control module, thus locking the doors.

When the driver's door or passenger's door is unlocked, pin 6 of the control module is grounded and current is supplied to all actuating motors for 1 second via pin 8 of the control module, thus unlocking the doors.

Central Locking Anti-theft Protection
By means of the key in the driver's door it is possible to secure all the car's locks centrally against theft (deadlock), i.e. the central locking motor is blocked so that it cannot be actuated by means of the lock buttons.

Turning the key in the driver's door past the locking position to the deadlock position, 90° below the neutral position, causes pin 12 of the control module to be grounded for about 0.1 seconds, following which pin 12 is supplied with current for about 1 second via a logic circuit.

The central locking system is now protected against theft, which can be seen from the position of the lock bolt in the driver's door, i.e. the cylinder does not spring back to the neutral position.

When unlocking from the deadlock position, the key is turned back to the unlocked position through 135° from the deadlock position.

The deadlock function can only be used after central locking and can only be operated from the lock cylinder in the driver's door.