Airbag light, passenger seat occupancy sensor

[Da Prophecy]

I recently had my seats out of my 97 328i to detail the car and now have my airbag light on. After researching the issue it seems that the passenger seat occupancy sensor pad is the likely culprit as the airbag light appeared when I had turned on the car without the occupancy sensor being connected.
Now that I have reconnected the sensor the light remains. I guess what I am asking is, does a fault due to a missing occupancy sensor require clearing using the srs tool or should it automatically clear if the sensor has been reconnected?

Also, can someone verify that if the passenger seat occupancy sensor is faulty that the result would be both airbags being deployed in and accident whether or not a passenger is present?

Kyle Rogers

[dvmotorsports]

The fault will not clear on it's own. If you do have the tool or access to one, you can reset it yourself. If the light persists, I suggest taking it to the nearest dealer to have the issue looked into further. An OC3/Seat Mat Sensor is a job you don't want to tackle on your own.

[David Mc]

The reset will more than likely rectify the problem but there are a couple of alternatives to replacement if the seat occupancy sensor proves defective:-

1. You can take the car to a dealer and have the SRS module reprogrammed to ignore the passenger side seat occupancy sensor and deploy both air bags in the event of a crash, regardless of whether the passenger seat is occupied or not. This process will require a second trip to the dealer for restoration of SRS programming if you later decide to replace the seat occupancy sensor.

2. Go to this free hosted site 4shared - free file sharing and storage - share folder - My 4shared and download instructions (seat occupancy sensor bypass) to make a little circuit so that the SRS module thinks the passenger seat is always occupied (again both airbags will deploy in the event of a crash). The circuit costs around 50 cents to build, does not need a circuit board, fitting will not damage your car and is 100% reversible if you decide to replace the occupancy sensor at a later time.

I have purchased a replacement sensor mat to fit to my vehicle after the original failed, but built the circuit (which has worked flawlessly) so that I didn't have to put up with the warning light until the sensor is replaced.

[Da Prophecy]

The fault will not clear on it's own. If you do have the tool or access to one, you can reset it yourself. If the light persists, I suggest taking it to the nearest dealer to have the issue looked into further. An OC3/Seat Mat Sensor is a job you don't want to tackle on your own.
__________________
BMW Technician

Yes the seat mat looks like it would be a big job to install but if it is only the control module it would be an easy job. Will the code reader only indicate that the passenger seat occupancy sensor is at fault or will it go into depth about whether it is caused by the mat or the control module mounted beneath the seat? My guess would be that it will only indicate the occupancy sensor and it will be left to the user to determine which of the mat, control module or both to replace.

Kyle Rogers

[dvmotorsports]

Originally Posted by Da Prophecy

Yes the seat mat looks like it would be a big job to install but if it is only the control module it would be an easy job. Will the code reader only indicate that the passenger seat occupancy sensor is at fault or will it go into depth about whether it is caused by the mat or the control module mounted beneath the seat? My guess would be that it will only indicate the occupancy sensor and it will be left to the user to determine which of the mat, control module or both to replace.

Kyle Rogers

I have never seen the module go bad. Not saying it doesn't happen, but i haven't seen it. The seat mat sensor is fairly common (on newer vehicles). And as I am not familiar with the scan tool you are using, i cannot attest to how in depth it will go. The thing here is if you do reset it, and it doesn't come back on, you are set. But as I stated before, if it repeats, i do recommend a trip to the dealer. If that is the route you have to go, you will not have to worry about figuring out if it is the module or mat. That will be the responsibility of the dealer.

So if you can come to terms with the fact that you may need to go to the dealer, then the only thing you have to worry about is the bill. I know that sucks, but it's the woes of BMW ownership, or any car for that matter.

[Da Prophecy]

Thanks for the replies.

I don't have the reset tool but after calling around for a price to have the fault cleared I think I will order the tool and start by simply clearing the fault to see if it comes back on its own. I know that the airbag light came on when I turned on the car without the seats in, so it is likely that just clearing the fault will remedy the problem.

Once again thanks for all the replies.

Kyle Rogers

[Signotime]

Originally Posted by Da Prophecy

I recently had my seats out of my 97 328i to detail the car and now have my airbag light on. After researching the issue it seems that the passenger seat occupancy sensor pad is the likely culprit as the airbag light appeared when I had turned on the car without the occupancy sensor being connected.
Now that I have reconnected the sensor the light remains. I guess what I am asking is, does a fault due to a missing occupancy sensor require clearing using the srs tool or should it automatically clear if the sensor has been reconnected?

Also, can someone verify that if the passenger seat occupancy sensor is faulty that the result would be both airbags being deployed in and accident whether or not a passenger is present?

Kyle Rogers

The light will not go.. The dealer is the only option. Will cost you £40.00 in UK.