My turn at the infamous airbag light

[kezug]

I have a 98 2.8 Z3 (built 10/1997) at 83,000 miles and while sitting at a gas station, car running and then leaving, somewhere in that time, the air bag light came on. I want to say it was going to be when my wife got back into the car and it came on while she was seating herself and buckling up but I dont have that evidence. It was just a short moment after, when I glanced down and saw the red light.

So, I have searched and skimmed through the various threads but that took me into a time warp and back, so are my only options to

a) ignore it (which I cant do)
b) try my OBD II bluetooth to get a code (which returns nothing as it seems to only bring back CEL codes)
c) get a tool like B800 SRS scan (or B8300??) and get the code, address, then reset and fingers crossed
d) invest in the time/effort of INPA to get code, address it, then reset and fingers crossed

What is the best option here?

Also, I realize that there is no 1 size fits all, but what is common in this situation? Is it that some of the connectors under seat need DeOxIt cleaning and reconnecting, reset and should be good to go?

What is the WORST scenario? (air bag is not deployable in the event it needs to be deployable)?

[z3forlife]

Best option is set up a laptop with INPA from the z3 diagnostic thread. It’s free other than the cables you need. BMW factory software. Typically seat belt tensioner causes airbag light but without INPA you’re just guessing.

[IndianaRoadster]

Best option is set up a laptop with INPA from the z3 diagnostic thread. It’s free other than the cables you need. BMW factory software. Typically seat belt tensioner causes airbag light but without INPA you’re just guessing.

+1, you will probably from time to time, have a need with your 26 year old car, to diagnose an issue. You can't beat the BMW program that the tech's used when the car was new.

[rasmuw]

The light could be related to the seat occupancy sensor. If so, your have to take the seat upholstery off, or buy a gizmo to fool the computer.

[KBH22102]

My Foxwell NT 510 reads the SRS codes. In my case I have the passenger buckle causing the fault. to date it responds to cleaning with DeOxit sprayed directly into the buckle and then latching and unlatching a few times. But I bought a replacement buckle assembly for the inevitable day when it fails.

[devmast]

I agree. Start by spraying some deoxit in the seat belt receptacle and latching and unlatching the the buckle a few times. It has resolved transient airbag lights for me every time.

[328 Power 04]

I agree. Start by spraying some deoxit in the seat belt receptacle and latching and unlatching the the buckle a few times. It has resolved transient airbag lights for me every time.

This won't clear the codes, so this is working backwards.

Read codes
Fix problem
Clear codes.

[kezug]

All good advise, I have procured a laptop, but not I must read to determine which cable or perhaps based on some recent discussions, may not need a cable after all. Bluetooth has capability too, so must read to see if my Bluetooth will work and get those instructions.

Here is the OBDBII Bluetooth reader I have: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[328 Power 04]

It needs to be an INPA K+DCAN cable, preferably with a switch on it.

[IndianaRoadster]

Here's one on Amazon.
Screenshot_20241108_102219_Chrome.jpg

[Hoyt Clagwell]

What does the switch do?

[Ahwahnee]

That's the one I ordered a couple of days ago.

Description says...

"Switched inpa k+Dcan, You can use the switch to do more cars .Some cars need disconnect to use the inpa k+dcan,but others need connect. It can support more cars after adding the switch.Not every model need switch."

[ZJon]

Disagree with 328 on this, although it keeps coming back maybe twice per year, spraying contact cleaner in the driver buckle buckling/unbuckling vigorously numerous times and then clearing with the B800 has worked 2 or 3 times for me

The code I'm getting is driver buckle, which has been replaced, methinks this mechanical switch hangs up from time to time...

[kezug]

Disagree with 328 on this, although it keeps coming back maybe twice per year, spraying contact cleaner in the driver buckle buckling/unbuckling vigorously numerous times and then clearing with the B800 has worked 2 or 3 times for me

The code I'm getting is driver buckle, which has been replaced, methinks this mechanical switch hangs up from time to time...

But I would still need the INPA and Cable to reset AFTER and IF, only IF, that happened to be the one of many possible situations. So still have to reset via the INPA, of which I dont have, nor have a tool to reset such a code.

Unless, I am missing something.

[z3forlife]

My issue has never been the buckle but the harness plug below the seat. INPA should tell wether it’s the tensioner/pyro or buckle circuit.

[kezug]

Here's one on Amazon.
Screenshot_20241108_102219_Chrome.jpg

Ordered. Thank you.


Any recommendations for the following ? BMW 20-pin to OBD Adapter

[BimmerBreaker]

There's no need for an adapter cable, they just jump the pins at the port and then convert to OBD2 plug. The car already converts to the OBD2 plug... at the OBD2 plug... so if you just jump the pins like shown below, you can access all modules via the OBD2 port



Just remove the cap on the round port, install a jumper wire like pictured and reinstall the cap

[IndianaRoadster]

I know that you can jump pins, but just out of convenience, I went ahead and ordered the adapter. Here's one from ECS for $18, but like $14 on Amazon.
Screenshot_20241109_132659_Chrome.jpg

[kezug]

There's no need for an adapter cable, they just jump the pins at the port and then convert to OBD2 plug. The car already converts to the OBD2 plug... at the OBD2 plug... so if you just jump the pins like shown below, you can access all modules via the OBD2 port



Just remove the cap on the round port, install a jumper wire like pictured and reinstall the cap

As in, set it (jumping like you show) and forget it, regardless of doing any diagnosing or driving car?

[z3forlife]

No. This allows access to all modules through the obd2 plug instead of the 20 pin.

[Ahwahnee]

Here's one on Amazon.
Screenshot_20241108_102219_Chrome.jpg

By way of follow-up... I purchased that cable (already had a 20-pin adapter cable) downloaded the INPA to an old Windows 7 laptop and everything seems to work well.

[IndianaRoadster]

By way of follow-up... I purchased that cable (already had a 20-pin adapter cable) downloaded the INPA to an old Windows 7 laptop and everything seems to work well.

Glad you're good to go! I just leave the two hooked together and stored in the drawer in my tool cabinet. It's convenient to just pull it out, open the hood and plug it in.

[BimmerBreaker]

As in, set it (jumping like you show) and forget it, regardless of doing any diagnosing or driving car?

Yes it's fine to drive like that. I'll use it for real time diagnostics while driving on occasion - but usually if I don't need to access other modules for awhile I will unplug the jumper.

[sleeperz]

I know that you can jump pins, but just out of convenience, I went ahead and ordered the adapter. Here's one from ECS for $18, but like $14 on Amazon.
Screenshot_20241109_132659_Chrome.jpg

I bought one like this and added a programming switch.

[kezug]

I have 2 codes

16 analog status belt lock driver
Error Frequency : 1
-------------------------------
3 Supply voltage
Error Frequency : 4

I am not finding much on these codes when searching around:
for 16 - I found this thread - Unsure which of the 2 things discussed was the solution. Seemed like I could clean the buckle connect and seat if that works. Or mess with wiring under the seat?
If I do disconnect/spray electrical parts cleaner/reconnect, do I just do ALL the cables or the seat belt lock driver cable (which one is that)? Is this requiring the seat to be removed?

For 3 - Unsure of what to make of 3 Supply Code - seems this is unrecoverable???

Also, I am assuming that which ever I do try, I still must do a clear code, then see if my solution worked?
Also, but since I have INPA, if I am am going to be unplugging wires, do I still have to disconnect battery first or simply just clear the code that pops if I dont?






I also felt I should ask about this. Why does my Sensor say No?