Initial Inspection and Diagnostic Overview

Functional Description

The airbag control module (J234) is located behind the console on the tunnel. It is equipped with DTC memory. The On Board Diagnostic (OBD) Data Link Connector (DLC) is located under the dash on the drivers side.

The control module detects Diagnostic Trouble Codes (DTC) in the airbag system and stores them in a permanent memory.

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

After the ignition is switched on, the airbag warning lamp (K75) comes on for about 4 seconds and then goes out again, if the lamp then flashes for a further 15 seconds this signals that the front passenger airbag, is disabled.

- If the warning lamp (K75) does not go out again after about 4 seconds, then the voltage supply to the airbag control module (J234) is inoperative. Check DTC memory.
- A DTC is present if the warning lamp (K75) lights up again. Check DTC memory.
- If the warning lamp (K75) flashes continuously then the control module (J234) must be replaced.

To commence trouble shooting, initiate On Board Diagnostic and retrieve the stored information with the VAG 1551/VAS 5051 Scan Tool.

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


WARNING!
- Only visual check of wiring!
- Do not perform electrical continuity tests or measurements to igniter circuits!
- Only check wiring with ignition switched off!