Initial Inspection and Diagnostic Overview

Airbag System, On Board Diagnosis (OBD)

Function
The Airbag Control Module -J234- is located behind the console on the tunnel. It is equipped with a DTC memory. The On Board Diagnosis (OBD) connection is located beneath the cover under the steering wheel.

The control module detects malfunctions in the airbag system and stores them in a permanent memory.

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

After the ignition is switched on, the airbag Airbag Malfunction Indicator Lamp (MIL) -K75- comes on for about 4 seconds and then goes out again. If the lamp then flashes for approx. 15 seconds this signals that the front passenger airbag, is disabled.

- If the Airbag Malfunction Indicator Lamp (MIL) - K75- does not go out again after about 4 seconds, then the voltage supply to the Airbag Control Module -J234- is faulty. Interrogate DTC memory. Check DTC Memory (Function 02)
- A malfunction is present if the Airbag Malfunction Indicator Lamp (MIL) -K75- lights up again. Interrogate DTC memory. Check DTC Memory (Function 02)
- If the Airbag Malfunction Indicator Lamp (MIL) - K75- flashes continuously then the Airbag Control Module -J234- must be replaced.

To commence fault finding, initiate On Board Diagnosis (OBD) and retrieve the stored information with the Vehicle Diagnosis, Testing and Information System VAS 5051 or the scan tool V.A.G 1551 1).

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

WARNING:
- Only visual check of wiring
- Do not carry out electrical continuity tests or measurements to igniter circuits.
- Only check wiring with ignition switched off.

1) Some functions which could previously be performed with V.A.G 1551/1552 must now be performed with the Vehicle Diagnosis, Testing and Information System VAS 5051 in the operating mode vehicle On Board Diagnosis (OBD).