Airbag Ignitor Circuit - Resistance Testing

Group 72
Equipment and Accessories

Bulletin Number
72 01 92 (3633)

Woodcliff Lake, NJ
September 1992
Product Engineering

SUBJECT:
Testing Resistance of Airbag Igniter Circuit

MODELS:
All Equipped with Airbag (SRS)

General Information:
Certain troubleshooting procedures during airbag diagnosis involve measuring the resistance (ohmic value) of the igniter circuit of the gas generator, using a harness adapter to open the shorting bridges in the connectors.

The Repair Manuals for all vehicles equipped with airbag state that only the multimeter function of the BMW Service Tester is to be used for making these measurements. However, situations may arise in which the use of the Service Tester is impractical or impossible (such as a temporarily inoperative Service Tester).

In view of these possible situations, BMW has approved the use of a digital multimeter for making these measurements, provided that the current through the test leads during resistance measurements is sufficiently low to prevent deployment of the airbag. BMW has tested and approved the Fluke models 83 and 87 for these measurements.

The BMW Service Tester Multimeter function should be used for testing SRS circuits at all times. If this is not possible, the Fluke Model 83 or Model 87 may be used. Use of other, unapproved multimeters may result in unintentional deployment of the airbag, causing the destruction of an expensive component (airbag assembly) and possible injury.

It is still absolutely necessary to comply with all other safety-related procedures conjunction with diagnosis and repair of SRS systems (e.g., disconnection and isolation of B-cable, storage of airbag unit with impact pad facing upwards, etc.)

Please ensure that all members of your Service Department are familiar with this information and comply with these procedures.