Passenger seat airbag light

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Rocketbike
Joined: Thu 17 May, 2012 20:12
Posts: 83

  Z3 roadster 1.9

Passenger seat airbag light

Post by Rocketbike »

A while ago I took out my perfectly functioning cloth interior on my 1998 1.9, and fitted a leather one. The airbag light came on, and the diagnostic machine indicated it was the passenger occupancy mat. Unfortunately I did'nt try and get it reset before I sold my old interior. I've since tried another secondhand seat, and a couple of the bypass fittings you can get on ebay to tell the system the seats occupied and put the light out, all with no joy. The only other thing was when I first put the seats in, the drivers side seat belt retraction thing had been fired (seats from a write off) which when I realised, I changed for the original, but it was plugged in that way, but was drivers side only (assume passenger side was unoccupied in the accident as it didn't go off). So now, having tried severall things and having had a couple of mechanics try and reset and fiddle with the seats, doing basically the same stuff I have changing parts, I'm down to buying and fitting a new occupancy mat (about £200, or getting a second hand one of known condition) Overall I'd rather find a specialist/someone who knows these and get them to sort it out, it'd probably be cheaper than me buying possibly unneccesary parts Has anyone any thoughts or experience that might help me sort it all out before MOT time?
Thanks :)
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BladeRunner919
Joined: Fri 17 Feb, 2012 20:18
Posts: 2225

  Z3 roadster 1.9

Re: Passenger seat airbag light

Post by BladeRunner919 »

Have you reset the codes after putting in the bypass sensor? In fact, does your car actually have a passenger airbag - my '98 1.9 doesn't.
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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 10:35
Posts: 10170

  Z3 roadster 1.9
Location: Cheshire

Re: Passenger seat airbag light

Post by Robert T »

Airbag module shows as June '98 to April '99 for pre-facelift, so I presume it was an option, as my 01/99 built 1.9 doesn't have one.

As said above, the airbag light latches on when a fault is detected and it won't go out again until cleared with a special tool or laptop. Does the occupancy mat connect through the same connector as the pre-tensioner? If it does, then these are known as a known weak point in the system, and are responsible for the typical problem of the light coming on after moving the seat - that is not to say that they couldn't cause a fault all the time - might be worth checking the condition of the wiring to the connectors and that the connectors themselves are making a good connection.

Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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Rocketbike
Joined: Thu 17 May, 2012 20:12
Posts: 83

  Z3 roadster 1.9

Re: Passenger seat airbag light

Post by Rocketbike »

It does have an airbag, and it has been reset using the plug in diagnotic kit that identifies the fault code, and displays as a message on the screen what the fault is. If you then reset it using the same kit, the fault, goes off the screen and the airbag light goes out, but it only stays off for a few seconds and then the light comes back on and the fault reads the same. It's done that with two seperate seats, and two bypass sensors, but prior to changing the seats, I had no issues at all, and as far as I can tell there is no damage to the main wiring that I have done by moving the seats around
Thanks :)
Jonco
Joined: Sat 04 Jun, 2011 07:24
Posts: 402

  Z3 roadster 1.9
Location: Cheshire

Re: Passenger seat airbag light

Post by Jonco »

BladeRunner919 wrote:......... In fact, does your car actually have a passenger airbag - my '98 1.9 doesn't.
Nor does my '98 1.9. If you have access to INPA you can check it on there. The screen on mine comes up with same display as Robert T's example in the KB `INPA how to'. http://www.zroadster.net/forum/viewtopi ... 42#p332640

Also you can look at this link which recently appeared in separate topic (apologies to Phil)
http://www.bmwarchiv.de/vin/bmw-vin-decoder.html for factory spec.
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Robert T
Site Admin
Joined: Mon 12 Jun, 2006 10:35
Posts: 10170

  Z3 roadster 1.9
Location: Cheshire

Re: Passenger seat airbag light

Post by Robert T »

I wasn't implying that you had damaged the connector - more that there is a known fault with the wiring loom and BMW have a modified harness that can be fitted - I have had mine replaced on the drivers seat after my airbag light came on for no reason. There is also no guarantee as to the condition of the wiring on the seat that you have installed - the person that removed it may not have taken as much care as you did.

Whereabouts on the loom does your bypass fit?

Cheers R.
Arctic Silver '99 Z3 1.9 & Black '59 Frogeye 1275cc
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Rocketbike
Joined: Thu 17 May, 2012 20:12
Posts: 83

  Z3 roadster 1.9

Re: Passenger seat airbag light

Post by Rocketbike »

I'll get the seat out again and check the connectors for damage an obvious faults. The wiring harness change sounds like quite a major fix, or is it just a short section? The bypass fits into the car side of the harness, breaking the link between the seat and car, and is a male fitting into a female. The machine one of the guys used to diagnose the fault is known as a 'Solus', but I haven't used that myself. The other guy I don't know, he looked while servicing it and I left it with him. Beyond basic checks I'm a bit out my depth with anything else, so am keen to find an enthusiastic specialist if I can, somewhere in the Midlands ideally
Thanks
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