Jan 6, 2013
Hi guys,
I am doing lots of BMW airbag work so I come all sort of crazy issues. Those issues as you may know are often due to a faulty seat occupancy sensor.
But other issues can also affect your airbag system.
Yesterday I came across a clean e46 with the following faults (Through BMW Scanner 1.4 / INPA had the same fault logged). I often use BWM Scanner for its simplicity and quick turnover diagnostic it offers, but when the faults are multiple, I usually use BMW INPA too, just to confirm.
So here you go, the actual faults. Usually when you have more than one of two, this is a sign something is wrong after the seat, not the seat itself.
[B]BMW Scanner 1.4 faults[/B]
SRS 20/82 – Sensor, side airbag, left, line fault
18/C2 – Seat occupancy detector
06/20 – Belt tensioner, passenger side
[B]BMW INPA faults[/B]

So I removed the passenger seat, connections were all very clean, nothing was cut off, the original equipment was there, including the seat occupancy sensor. I often see previous attempts of fixing airbag issues in there.
So I dig a bit more and notice the carpet is quiet wet. So I remove the carpet on the passenger side (Just lift it really) and noticed a nice puddle of water and the satellite sensor that is sitting here is all rusty. That’s it, the issue has been identified. If this sensor goes belly up, you will have multiple faults on the airbag system.
See the white/green powder all over the sensor. It is dead basically.


So after finding a replacement and the carpet/car dried up, I unplugged the battery for a few minutes (Recommended when you do this before putting new parts in) plugged in the new satellite impact sensor and all the faults were gone, a part from the seat occupancy sensor itself.
No worries so I install a bypass, and now it is all good. A quick reset of the fault. Airbag light goes away.

I remove the key, turn on the car again, and that’s it, the light comes up for a few seconds then goes away.
All good.
I hope this helps
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