Coding out the seat belt pretensioners and occupancy sensor

[TPE]

Hello All,
I am in the process of preparing my m3 for the track and have removed the two electric seats and to no surprise now have an airbag light in my cluster. I have done some research and found the below to be a solution by reusing the appropriate parts from the seats. This info was provided by Paraklas on e46fanactics:

1. Install the racing seats and use the OEM belt pre-tensioner unit. Connect the tensioner unit with the wiring loom under the seat.
2. Get an occupancy sensor bypass module ($15 /ebay) and connect it with the wiring on the passenger seat along with the tensioner.

I was thinking, why would I remove the weight of the seats, only to add some of it back in? To give you all a little more details on the direction of the build, I just installed a Kirk racing roll bar and have a Racetech RT4009 stealth on the way from New Zealand so that I can run a 6 point Schroth Flexi harness. As mentioned before, a solution is to install the original seat belt buckles which I don't need with the 6 point harness.

Does any one have any experience on how to code out the seat belt pretensions and the seat occupancy sensor using NCSExpert or some other tool?

Thanks,
Josh

[TPE]

I just stumbled upon some info of someone with an e38 saying to set the following to "nicht_aktiv" in the ABG trace file:
"GURTSTRAFFER_FAHRER_1" (driver's pre-tensioner)
"GURTSTRAFFER_BEIFAHRER_1" (passenger pre-tensioner)

"GURTSCHLOSS_FAHRER_1" (belt buckle driver)
"GURTSCHLOSS_BEIFAHRER_1" (belt buckle passenger)

Can any confirm or correct if this is what needs to be set to not active in order to code out the pretensioners and the occupancy sensor?
Also, I would hope that after coding these features out, that the steering wheel and passenger dash airbags would still function correctly in the case of an accident, someone please confirm.

Thank you all in advance,
Josh

[TPE]

So I spent a lot of time today trying to figure it out and eventually was able to get NCS Expert to code the ABG module. To determine which items to set to "nicht_aktiv" I read the airbag codes via INPA and then went into my ABG trace file in NCS Expert to changed the following following trace file lines:

BELT TENSIONER DRIVER:
GURTSTRAFFER_FAHRER_1
nicht_aktiv
GURTSTRAFFER_FAHRER_2
nicht_aktiv

BELT TENSIONER PASSENGER:
GURTSTRAFFER_BEIFAHRER_1
nicht_aktiv
GURTSTRAFFER_BEIFAHRER_2
nicht_aktiv

BELT LOCK DRIVER:
GURTSCHLOSS_FAHRER_1
nicht_aktiv
GURTSCHLOSS_FAHRER_2
nicht_aktiv

BELT LOCK PASSENGER:
GURTSCHLOSS_BEIFAHRER_1
nicht_aktiv
GURTSCHLOSS_BEIFAHRER_2
nicht_aktiv

RECOGNITION SEAT ASSIGNMENT:
ERKENNUNG_SITZBELEGUNG_1
nicht_aktiv
ERKENNUNG_SITZBELEGUNG_2
nicht_aktiv

After I made the changes above, I cleared the airbag error codes in INPA and now no more airbag light on the cluster.

[Obioban]

I wouldn’t code out things you don’t need to...

[TPE]

I wouldn’t code out things you don’t need to...

Could you please elaborate why? I’m guessing you would prefer to leave the airbag light on?

[Obioban]

Could you please elaborate why? I’m guessing you would prefer to leave the airbag light on?

I just meant, I wouldn't code out any systems you still have installed in the car. E.g. in mine, all I had to code off was the passenger seat occupancy sensor (which, strangely, I don't see on your list) to not get an airbag light. I have my harnesses set up to use the factory belt receiver, so I retain pretensioner functionality and seat belt warning lights (which are not on when the harness is in use).

What is "recognition seat assignment"?

[Steve]

The airbag module really doesn't seem to like being coded. After bricking mine, I just got one of those cheap sensors off ebay for the occupancy sensor. You could also make one yourself if you're handy.

[jareds941]

Depending on your setup, the airbag module can be removed, and so long as you put some electrical tape over the ground wire, and do all of this with the battery disconnected, you won't get a light. That's what I did on my car...no bags, no module, no light.

I did have a question on the seatbelt light and coding. I've removed 100% of the seatbelts from my car. I don't have any alarms or alerts, just the solid state red seatbelt light on the dash. What needs to happen for me to get that to go away?

[BMWahba]

The airbag module really doesn't seem to like being coded. After bricking mine, I just got one of those cheap sensors off ebay for the occupancy sensor. You could also make one yourself if you're handy.

Link to what you're referring to? I have an airbag light and haven't gotten around to coding it out. I think its a faulty passenger occupancy mat.

[Steve]

Link to what you're referring to? I have an airbag light and haven't gotten around to coding it out. I think its a faulty passenger occupancy mat.

This is the one I used on my E36 but I don't remember it costing this much, seems like these used to be around $8.

https://www.ebay.com/itm/Seat-Occupa...IAAOSwVFZZci5-

[BMWahba]

This is the one I used on my E36 but I don't remember it costing this much, seems like these used to be around $8.

https://www.ebay.com/itm/Seat-Occupa...IAAOSwVFZZci5-

Nice i'll give this a shot!

[TheEnd]

The airbag module really doesn't seem to like being coded. After bricking mine, I just got one of those cheap sensors off ebay for the occupancy sensor. You could also make one yourself if you're handy.

Yea, this is a risk, occasionally you can drop into a situation where the coding says one thing, but the module detects stuff on some pins that should be empty, and it marks itself as faulty with an internal error code which can't be cleared.
This is similar to the sort of codes you get on airbag modules when they go off, and the module won't respond to requests to clear it.
Apparently some modules can be worse than others, but it is always a risk.

[jahaddow]

Simple job using Pasoft. Only have to untick occupancy sensor installed and job done. Also untick belt tensioners if you disconnected those.

[BigRussia]

Quick bump, as I am currently trying to resolve the passenger occupancy sensor airbag light from installing bucket seats and this was the most relevant thread I could find.

I disabled ERKENNUNG_SITZBELEGUNG_2 in the ABG module using NCS Expert and NCS Dummy (Dummy interpreted my ABG module as MRS4_16.C32), but when I went to write the updated file to the module in NCS Expert I received an error popup and a 'coding is faulty' message... Needless to say the airbag light is still on in my cluster, any advice as to what I need to do/change?

I had figured ERKENNUNG_SITZBELEGUNG_2 to be the right option to disable, roughly translating to Passenger Occupancy Sensor.

Maybe I need to also disable the drivers occupancy one as well? Though, everything I read online relating to this issue always mentioned the passenger occupancy mat sensor.