Component Tests and General Diagnostics

Convenience System (vehicles With Power Windows), On Board Diagnostic (OBD)

Functional description

The new generation of central locking operates on the electric motor principle as compared to the previous pneumatic operation.

The locking units located in the doors (door lock) have an electric motor.

The motor locks the door and also takes care of the "Safe" condition, i.e. after locking at an external lock (door lock, tailgate, radio remote control) the vehicle is protected against theft and can no longer be unlocked from the interior. The feedback on the respective condition in control unit occurs via the contact switch in the locking unit.

All the known convenience functions can be performed with the electric convenience system, interior lights control, ATA with interior monitoring, electric windows, mirror and the radio remote control.

If the airbag control unit is triggered, a signal is sent to the convenience control unit to unlock the doors.







The convenience system control unit -J393- is located under the dash panel and is secured with a bracket to the steering column. It is equipped with a DTC memory. The On Board Diagnostic (OBD) connection is located under the driver's knee bar to left of the steering wheel.

The control unit recognizes DTC's and malfunctions in the central locking convenience system (convenience system includes central locking, anti-theft alarm, electric windows, radio wave remote control, mirror) and stores them in a non-volatile memory.

Testers VAG 1551 and 1552 can be used to check the DTC memories and code the control units as well as the function On Board Diagnostic (OBD) of the VAS 5051.

The function "Guided Troubleshooting" of the VAS 5051 should be used for troubleshooting in diagnostic capable systems. Using this system a systematic malfunction check is guaranteed, from the fuses via wiring, connections in the current path.:

The malfunction information displayed is used to refer to a DTC table with notes on the possible causes for directed repair measures.

Malfunctions which can be attributed to a temporary open circuit in the wiring or a loose contact, will also be stored. These malfunctions will be displayed as sporadic DTC'S "SP".

Only statistical malfunctions are considered:
- Central locking inoperative
- Mirror positioning motor inoperative
- Electric window positioning motor inoperative
- CAN communication inoperative


NOTE: Before changing a component erase DTC memory, perform functional checks and check DTC memory again.