When I swapped carpet in my M3 a couple years ago I managed to cut a few airbag wires. The only way I could reliably verify which wires were an issue was to do a continuity check between the airbag controller module (whatever it's called) and the airbag that was reading as a fault. It was a bit of a pain getting to the connectors but once I had them it was easy enough to figure out which wires were a problem by looking at the wiring diagram.

 

Oh, definitely unplug the airbag and maybe even the battery while you go poking around in there.

 

BANG!

 

Thanks @dutchhome . I assume you're talking about the airbag module in the center console. (May be time to dust off repair manual for those diagrams)

There seems to be a lot of wiring behind the glovebox (relays etc) Does anyone know if the airbag wires go into a relay there?

 

Yes, was referring to the module under the armrest. Also, I’m not sure why I said “maybe” disconnect the battery. That should be “definitely”. I’ll update my post above in case someone runs across this thread later.

Regarding the relays, I don’t know. If you give me your year and model I’ll try looking up the wiring diagram for you.

 

This may help in a strange way. First of all be advised I have acquired quite a bit of knowledge about the seat pad sensors. I do know the electronics fairly well but I haven't reached expert status yet on Airbags. I did set one off for fun recently (off car of course) !!
So here are a few tid bits to help you while poking around.

Fuse 11 is for the safety restraint system (5 Amp see below)
I'm fairly sure there are 2 open airbag recalls out on your car. We have 3 E series and took them to the dealer for "free" air bag replacements. (free for us but likely at the expense of Tikata ).

An air bag instantly detonates when 9-12VDC is applied. Its no different than touching power to a 12vdc light bulb. . voltage
If you use a OBD reader that is BMW friendly , it can tell you the fault code for air bag system. I have a non bmw friendly one .. I use the free one at O'reillys which has the "BMW extensions" option. O'Reilly is often a great
help to me.

Here's a thread from fanatics that tells you a little about placement

SRS Airbag Light- Where is Airbag Control Module?

I have a 2000 328ci.. So A few weeks ago my airbag light popped up. I ordered the Peake Research SRS Tool and I pull up fault code 01, 01.. which seems to be.. Control Unit Fault, A/D Convertor. Anyone have this before? If so, what is the fix? Anyone know where the e46 airbag control module...

www.e46fanatics.com

I am fairly certain the airbag stuff all terminates to that control box under the arm rest .. but I've never looked.

 

www.bmwteka.com

I don't remember any relays in the airbag detonation side.
Supply to the SRS module, maybe. But everything FROM
the module's a direct shot.

I'd meter the darned thing at the SRS connector. Because there
is a door connector, and the wires flex after it. If it meters the
same 2.5 ohms for the squib, I'd be suspicious of the module itself.

t

 

Thanks Toby, looks like pins 18/19

BMW WDS Online

bmw wds online for all browsers

bmwteka.com

Confirmed in repair manual too (attaching for posterity)

 

It looks like you were able to get the wiring. Sorry for the late reply. Here is what I have. This is for a convertible, but I imagine the coupe is the same, or nearly the same.

OOPS! that one doesn't have pin numbers listed. I can get a different one.