Initial Inspection and Diagnostic Overview

Checking Airbag System Operation

1. Functional check of airbag warning lamp:

Turn on ignition. The airbag warning lamp must light up for approx. 5 seconds*. If the warning lamp remains dim, check bulb and/or supply voltage.

2. Functional check of error memory:

Turn on ignition and pull off fuse for instrument voltage supply for approx. 30 seconds. The airbag warning lamp must no longer indicate an error. Read off error and check if error code 58** (warning lamp: short to battery voltage or ground, error not present) is displayed.

Note: The central warning lamp and the Fasten Seatbelt symbol (US models only) must light along with the airbag warning lamp if an error is stored in the error memory.

3. Erase error memory.

4. Make sure that no covers, decals or similar items are fitted at the steering wheel and in the passenger airbag area.

5. Check components visually for damage and modifications.

6. After checking the system, confirm the check in the appropriate fields of the warranty and service booklet.

* As of manufacturing date June 11, 1992, the switchon time of the airbag warning lamp is reduced to approx. 2.5 Sec.

** As of software level B 01:30 (Airbag warning lamp: Signal implausible, not present).


Diagnosis / Troubleshooting

The airbag system is continuously monitored by a diagnosis unit in the control unit. If a fault occurs, it is indicated by a warning lamp in the instrument cluster.

In the event of a fault, the central warning lamp and this warning lamp come on. In cars for the USA, the fasten seat belts symbol also lights up.

The airbag warning lamp comes on for approx. 5 seconds when the ignition is switched on, and then goes out. When the engine is started, the warning lamp again comes on for approx. 5 seconds.

Should the warning lamp come on again later, this indicates a fault in the airbag system. The fault can be read out with System Tester 9288 and Flashing Code Tester 9268.

Note: The control unit needs approx. 70 seconds to identify all faults in the system, and the ignition must therefore be switched on for at least this time.

After a fault in the airbag system has been identified and rectified, the fault memory must be erased.

If any components are exchanged, this must be noted in the warranty and maintenance booklet. The document number should be attached in the free space provided. The document number is shown on an adhesive label which can be torn off the spare part.

Following an accident in which the airbag system was activated, the following components must be removed and renewed:

- control unit

- both front sensors

- contact unit

- both airbag units

If non-activated airbag units have to be removed, they must be ignited electrically before being disposed of.