E39 airbag light coming on occasionally when passenger seat weighted

I had a passenger kneel on the front passenger seat ("Nooooooooooo....")

I noticed airbag light come on immediately so I think they damaged the in seat sensor (it's a net or mesh?).

Occasionally I get the airbag light come on when I have a passenger or even something like a backpack or heavy water bottle etc. It's not permanent. Hoping it sneaks through the imminent NCT, but I need to sort it anyway.

I understand that it's possible to code out the sensor so that the passenger airbag is always triggered in a incident. Any other options here? How much would a replacement sensor be and is it worthwhile on this car?

Secondary question: is this type of coding possible with an ELM bluetooth unit & app or does it require a full diagnostic tool? What app?

You can get a bypass kit on eBay for the occupancy sensor. Less than €20


This is the one

https://www.ebay.co.uk/itm/150987109709


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The easiest route to go is to code out the sensor.

NOTE, if you do go that route you need to code out the driver and passenger settings in the module, even though there is no driver's side occupancy sensor. If you only change one line then you will brick the airbag control module. The control modules are relatively cheap second hand (€20-40, plus coding) but why go down that route.



ERKENNUNG_SITZBELEGUNG_1
aktiv -> nicht aktiv
ERKENNUNG_SITZBELEGUNG_2 aktiv -> nicht aktiv

Plus you need to disconnect the black box with blue writing under the seat, before you code out the mat. i.e. The box should not be connected back in to the car. It is connected to the sensor may one one side and the yellow block connector on the other side, it's the yellow block connector side of that needs to be disconnected. Note only disconnect the connector for the sensor may inside this yellow connector, you still need the seat belt tensioner. Better still, remove the box from the car.

Thanks for the write-up, rebel. That's pretty nasty how it bricks the sensor. It does sound doable, but I haven't done any OBC coding nor have the right hardware. I have been meaning to get an old laptop with an RS232 port so I can give it a go, but an ELM bluetooth interface and a free app is as far as I've gone so far.

I ordered the unit Dave suggested, because I need to get it sorted this week before NCT.

Got the unit Dave suggested, very easy to install & seems to have worked. Just put it in today. Typing this from the NCT center so we'll see how it goes.

Quote:

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Originally Posted by outofbandii

Got the unit Dave suggested, very easy to install & seems to have worked. Just put it in today. Typing this from the NCT center so we'll see how it goes.

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Best of luck! [emoji1303]

Passed on this, expected fail elsewhere!