Tuesday 21 August 2012

A3 air-bag warning light..

The air-bag warning light has been coming on randomly on the instrument cluster in my Audi A3 (8L) for the past 4-5 years. Scanning the airbag controller with VCDS-Lite, revealed the following fault:
01578 - Airbag Deactivation Warning Lamp; Passenger Side (K145)
31-10 - Open or Short to Ground - Intermittent
I didn't worry about it, until my wife got a NR on her driving exam, after the examiner aborted the test seeing the warning light.

I've tried a number of things to fix it, detailed in my post to no avail. After reading some posts about people replacing their seats with airbag-less race seats and putting a resistor across the wires going to airbag controller to stop it warning about missing airbags , I decided to put a 1W 4K7 resistor across the passenger airbag deactivation warning light. This light lives in the top map reading light assembly in my model and looks like this:

A3 8L passenger airbag deactivation warning light

I've highlighted the terminals across which I've soldered the resistor.  This fixed the problem.  The passenger airbag deactivation warning lamp comes on still when the passenger airbag is deactivated via key operated control in the glovebox.

There are no more intermittent errors from the airbag controller module and most importantly, the general airbag warning light on the instrument cluster is quiet.

WARNING: if the warning lamp fully fails, the airbag controller will not know about it and will no longer warn you via the general airbag warning light on the instrument cluster.

-- ab1


Anonymous said...

Hi, i have the same problem as well and if this is the fix that would be brilliant. Just wondering as to where you got your resistor? Thanks in advance, Luke

belodetek said...

You could try http://uk.farnell.com/ and look for a ceramic 1W 4.7KOhm resistor. Or you could wak into a Maplin store and buy a pack of resistiors.

Just remember this is a work around, if the lamp does fail, your passengers won't know the airbag is deactivated (maybe).