Air bag problem - N95 resistance too low.

[M3 Compact]

D3 3.0Tdi DPF Sport.

Airbag light is on and when it's reset with VCDS it comes straight back on within a few seconds.
Using VCDS and Google I've made a few assumptions, some of which may not be correct.








Stage 2 igniter resistance is 3.2.



N95 is steering wheel airbag?
Low resistance = a short in the wiring somewhere, as opposed to a poor connection/plug?
If I remove the airbag, unplug it from the 'clockspring' and clear the fault code, the fault code becomes 'resistance too high'. I'm ruling out the clockspring as the culprit on the strength of this.
If I remove the airbag, leave it plugged in to the clockspring, disconnect the two small plugs on the rear and clear the fault code, the fault code becomes 'resistance too high'. I'm ruling out the wiring between the airbag and the clockspring as the culprit on the strength of this.


Which only leaves the airbag unit itself?

I have a B7 A4 Sport with a similar looking steering wheel (paddles excepted), could I swap the airbag unit from this in to the A8 to check?
Is coding the airbag unit much of a chew?

[M3 Compact]

OK - I'm a numpty.

It occurred to me last night that when I was checking the wiring with VCDS I wasn't aware of/didn't realise the significance of the two stage airbag, and that it could have been the stage two resistance exceeded that I was registering as being significant, while the stage one resistance could still have been too low....

It was.


So - even with the large yellow & purple connector unplugged from the clockspring/slip ring, the stage one resistance is still only 0.4 instead of the 2.5 of the others and it's still flagging as "too low".

This eliminates the airbag unit and the wiring inside the steering wheel? (The MFSW/horn/paddles all work ok.)

Given that a poor connection on the module side of the clockspring/slip ring would cause the resistance to be too high??? I'm now suspicious of a short within the slip ring.

I don't appear to have a tool that will reach the screws inside the lower steering column cowling. So Sunday's investigations are over.

[M3 Compact]

Google seems to strongly suggest the plug on the back of the slip ring/clockspring, which is the next point of investigation.
I'm confused by how this could cause the resistance to be too low tho, I'd expect the resistance to be too high if it was disconnected or the connection was faulty.

[M3 Compact]

Google seems to strongly suggest the plug on the back of the slip ring/clockspring, which is the next point of investigation.
I'm confused by how this could cause the resistance to be too low tho, I'd expect the resistance to be too high if it was disconnected or the connection was faulty.

Sorted (for now).


It is indeed the plug on to the back of the slip ring/clockspring.....









As mentioned in many VAG forum threads, the connection is very poor. It utilises a secure enough latching system, but obviously the connections inside are flaky. I had mine all reassembled properly with the airbag light out and the light came on again when I adjusted the steering wheel.
A permanent fix would involve removing the slip ring and fashioning a more secure method of connection, which will have to wait for another day.


Higher resistance for the driver airbag, which I think is correct....










I'm still confused about the low resistance flag tho.