Description of On-Board Diagnostics

Comfort System : On Board Diagnostic (OBD)

Function

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 module occurs via the contact switch in the locking unit.

All the known convenience functions can be performed with the electric comfort system, interior lights control, ATA with interior monitoring (see description of system on), electric windows, mirror and the radio remote control. Under "Accessories and Optional Equipment"

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

The comfort system control module (J393) is located under the carpet in front of driver's seat. It is equipped with DTC memory. The Data Link Connector (DLC) for On Board Diagnostics is located under the dash on the drivers side.

The control module recognizes faults and malfunctions in the central locking comfort system (comfort system includes central locking, anti-theft alarm, electric windows, radio frequency remote control,. mirror) and stores them in a non-volatile memory.

To commence trouble shooting, initiate On Board Diagnostic and retrieve the stored information with the VAG 1551 Scan Tool.

System tester VAG 1552 may also be used.

All the functions that were previously possible with the VAG 1551/1552 can be performed with the new tester VAS 5051 in operating mode "Vehicle On Board Diagnostic (OBD)":

See Operating instructions for vehicle diagnosis, testing and Information system VAS 5051.

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 DTCs "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.