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)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.
31-10 - Open or Short to Ground - Intermittent
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:
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.