front seat airbag - why 4 wires?

Goran · #1 12th July 2013, 02:00 PM

Does anyone know why the front seat airbags have 4 wires, two of which are brown.

The TT seats I bought have only 3 airbag wires, only one brown wire.

On this diagram (for an S8 apparently) it shows only 3 wires for the seat airbags? Or maybe the ones I circled are not the correct ones?

ainarssems · #2 12th July 2013, 03:11 PM

The ones you circled are head(curtain airbags) not the seat airbags. Seat airbags would be the ones on the ones on right side with only 2 wires.

Goran · #3 1st October 2013, 08:42 PM

sorry for delayed reply, thanks!
I am now looking at this again. Strange how Audi wiring diagrams dont match the actual wire colours.
It now looks like the D2 seat airbag is single stage, but has two earthing wires?
The Audi TT airbag is also single stage and has one earthing wire. So looks like this will work.

Whats confusing me at the moment is that the Elsa wiring diagrams for TT Mk1 do not match the actual TT airbag wire colours. I have so far tried looking up all TT's from 1999 to 2004 in Elsa, they all say the seat airbags have the driver's = green+, white-
passanger's = white+, blue-

But both of my TT seats have airbag wires black, blue (and the brown earh is the same). Also all the TT Mk 1 airbags I can find on ebay all have black, blue and brown. So how the heck do I know which is + and which is -?

unless, of course, the wire colour is from the plug on the controller side, not the plug on the airbag side?

notorious · #4 1st October 2013, 09:32 PM

ELSA is very accurate with wire colours.

On screenshot I see wire colours BEFORE connectors T3h and T3i. AFTER connectors colours can be different.

All connector pins are usually clearly marked on connector itself. Use those pin numbers for guidance. For example: T3h/1 means pin number 1 of connector T3h. Just find pin number 1 on the actual connector.

Goran · #5 2nd October 2013, 10:37 AM

Thanks, I will order a pair of controller-side connectors from A8parts, I'll need them anyway for a neat conversion.
Now just to figure out where the two brown earthing wires go from the D2 seat airbag (brown plug). Picture to follow tonight. If they just go to a earthing point in the car then no problem. If they go back to controller, then confusion. See Elsa doesn't have those wires on the diagram either. Maybe because they dont go anywhere?

notorious · #6 2nd October 2013, 03:20 PM

Earth goes only to car chassis