Central door locking system (VW Passat B4)

The central locking system (Fig. 8-29), which is part of the serial equipment of the car, includes pneumatic drives located in the doors, trunk lid and fuel tank filler flap. The pneumatic drive is operated by a pneumatic injection-vacuum pump with a built-in control relay. The lock lock switches are located only on the front doors. All locking drives, with the exception of the fuel tank filler flap drive, have electromagnetic safety devices. Locking the doors 12 s after the lock is engaged. On cars with a sedan body, the locking system pump is located in the trunk, and on cars with a station wagon body - under the instrument panel in a sound-insulating housing. The duration of the pump operating cycle is 3-7 s. The pump automatically switches off after 30 s of operation if an air leak appears in the system.