urg airbag light!

[Chopper D]

First potential problem with my new toy (besides a center console light that burned out ), the airbag light came on basically the next time I turned my car on after the 1300 mile roadtrip I took (car now has 117K miles). Was reading around some other general airbag threads and I guess I need to get it hooked up to a code reader or whatever...but is this usually a costly fix? I've read it could be as simple as some dirty wires, but I also read that sitting on your seat on your knee while reaching into the hatch can put too much weigh on one of the seat sensors and break them? What a joke! But quite possible, as I did this several times not even thinking that I could be damaging a potentially expensive sensor inside my seat.

Also, is it possible to do any kind of damage by moving around the wires underneath the shift boot? I was messing around a bit in there looking for the connector for the light up shift knob...that connector was actually wrapped in electrical tape and, dunno if it was coincidence, but it wasn't until after messing around in there that I then noticed the airbag light had come on.

Anybody in LA (the Valley) with one of these code reading tools who can help me out in exchange for a beer or two?!

[Z3speed4me]

I have everyone's favorite light on as well right now....personally since I want to get a few things checked anyway I'm going to have someone I know with the GT1 scan it for me for anything that comes up in general.... I am not sure off hand if normally scanners will show Airbag lights. If there is a corresponding CEL like occupancy sensor, the n possibly.

[Mr Bingley]

You can get an air bag light reader/reset tool on eBay for $30 or so--also available on Amazon. Probably you moved the seat and this tripped the light due to a bad connector/connection at the plugs under the seat--very common problem. Solution is don't move the seat.

[Chopper D]

You can get an air bag light reader/reset tool on eBay for $30 or so--also available on Amazon. Probably you moved the seat and this tripped the light due to a bad connector/connection at the plugs under the seat--very common problem. Solution is don't move the seat.

That would be nice if that's all it is...since I got the car nearly 2 weeks ago I've moved both seats around a bit but not too much really.

[speedyZ3]

The simplest and cheapest fix for sure! With the reset tool, even if you move it and set the light - just get the seat back to the sweet spot and clear it again. If you cannot let it go - you'll need the faults read from the airbag module, it will be "high resistance" in the belt tensioner, SBE, buckle switch...something with wiring under the seat. Replacing the wires indicated will be the repair.

[Chopper D]

Well you guys are certainly confident, I hope that's all it is...is this much more common a problem with Z3 airbag systems as opposed to a real airbag problem? None of the other airbag threads I read mentioned anything about it simply being a funny seat position. Is this just another funny Z3 quirk?

[Z3speed4me]

I always wondered.... With the airbag light on is the system going to malfunction and not deploy if there were an accident?

[speedyZ3]

It's the wiring - moving the seat disturbs the wires, which through age naturally cause increased resistance. The resistance of these circuits is monitored by the ctrl module, it has a range of resistance that is acceptable - sets the light if the resistance goes out of the range. Moving old wiring around often will spike the resistance enough to make it set the light off.

[Chopper D]

Are we talking moving the seat AT ALL? Or back and forth or up and down or tilting back and forth or is any movement just likely to cause this? Would be kind of annoying to have to reset every time I let my shorter room mate drive the Coupe.

[benhenny]

Get the reset tool, read the error. It's probably the "belt tensioner" error, which means that it's a loose wire. Put your seat all the way forward, reach under and make sure the connections are good and tight, then reset the light - it's really easy to do. The reset tool that I got required me to connect it to the plug in the engine compartment - it didn't work with the port on the passenger's side.

The consensus is that, even with the light on, the bag would deploy if there were an accident.

My post on the subject:

http://forums.bimmerforums.com/forum...6#post25886546

[Chopper D]

Thanks guys, and what is the name of the tool I'm looking for on EBay? Is it specific to Z3?

[benhenny]

It was the Loftek airbag reset tool from Amazon I ordered.

[Chopper D]

Awesome...thanks! I'll try and get it this weekend and report my findings.

[Mr Bingley]

Are we talking moving the seat AT ALL? Or back and forth or up and down or tilting back and forth or is any movement just likely to cause this? Would be kind of annoying to have to reset every time I let my shorter room mate drive the Coupe.

It's an easy excuse not to let anyone drive your Z3.

[speedyZ3]

+1

[Chopper D]

It's an easy excuse not to let anyone drive your Z3.

Hard to argue that

[CMM3]

There is an easy way to bypass both the seat belt tensioner and the seat occupancy sensors, one of which most likely the cause.
To do the tensioner its as simply as putting a resistor in. The occupancy sensor bypass consist of a diode and resistor.
I have race seats in my car & no air bag lights.
will see if I can dig up the details if anyone is interested?

[Cheshire2002]

There is an easy way to bypass both the seat belt tensioner and the seat occupancy sensors, one of which most likely the cause.
To do the tensioner its as simply as putting a resistor in. The occupancy sensor bypass consist of a diode and resistor.
I have race seats in my car & no air bag lights.
will see if I can dig up the details if anyone is interested?

Yes please. Very interested.

[speedyZ3]

Also curious...

[BenFenner]

CMM3, highly interested in that information as well.

Edit: It looks like the Manifesto already has the info? Sensor Occupancy Matt Sensor Cheat!!!