The Haynes manual says that you should unplug the air bag cable connector before doing any work around the driver's seating position. It says there is a capacitor that is designed to fire the air bag even if the battery is disconnected. But according to the diagram, the cable connection really hard to get to--under the carpet at the trans tunnel.

A mechanic told me, no problem. All you have to do is to disconnect the battery 15 minutes before you want to work on the car. This will be enough time to discharge the capacitor and you can work on the dash or whatever, with no risk that something will set off the air bag.

Seems to me that a capacitor with enough kick to ignite what is in effect an explosive charge would take longer than 15 minutes to discharge. Does anyone have any inside-Volvo information on this? Is 15 minutes long enough? Or is there some other way to temporarily deactivate the air bag? What do Volvo dealer shops do when they want to work around the steering column?

Thanks for any help you can give.

Doug Harvey

I routinely work in and around the airbag module without depowering the system. If you're going to be working in the DIRECT vicinity of the airbag crash sensor, wiring, or the steering column, it is a good idea to disconnect the battery cable. If you're so inclined, disconnecting the SRS connector will totally deactivate it.

I do a lot of airbag/explosive seatbelt installations and switching, and I've never been afraid to work around the systems. But common sense rules apply. Don't mess around when static electricity is a concern. Don't drop airbags or pyrotechnic seat belts, always carry airbags with the exploding side AWAY from you. Never store airbags with the airbag side down. Don't store in wet areas. And so on. Working in the console or under the dash is a concern. If you use caution, however, you should see no problems.

One last thing; when you disconnect parts of the system to do work on it, or other electronics in the car, sometimes you will end up with an SRS fault code. That is easily reset, and if it doesn't come back after resetting the system, it is usually not a problem that requires further investigation.
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Chris Herbst
1992 745, 68k

And others:
93 944, 150k
90 245, 110k
88 744, 160k
87 245, 185k

The mechanic is correct, but if you want to be safe, let it sit for an hour.