BMW 330I 2006 E90 240K miles
I've been looking online and I am finding out that this problem is huge, lots of people are having the same issue. The Airbag Light is ON and you can't turn it OFF easily. In this post I will show you how to clear the code... but you must check a few things which I will go through in this post. I tried it and it worked...
My Foxwell 510 Elite with BMW software
Side note about my car:
I've been driving my car with the light Airbag light ON for about 6 months, because other than the light being ON, the car drives good, no other issues. Now I know that in the event of an accident, the airbag may not deploy, but that was a risk I was willing to take.
How did it happen... My Theory...
I had a very bad battery, 3 years old. they really only last about 2 years. If it goes beyond that, a lot of the electronics don't like it and they start to "Fail", they are not really bad, but the car thinks they are, because it's not receiving the correct voltage from them.... Thus we get to the Air bag.
I started to get sporadic failures from the air bag, and they would simply go away after I drove for a day, then it would come back again, when I started the car... Then after a day or so it would go away.
Most people are replacing the "Passenger Seat Occupant Sensor", which is what most would deduce from the failure warning on the Nav Screen... I almost did the same thing, that could be the problem in your car, best thing is to run a scanner like the Foxwell 510 to know for sure. No guesswork... This scanner will tell you which part is bad: The Occupant sensor, the Seat Belt latch, or the MRS safety battery terminal. All 3 will give you the same warning message.
Not the Seat buckle...
I checked the Seat buckle which has Pyro on it to deploy in the event of an accident, but it measured good. about 2 ohms. I ended up using a piece of zip tie to push up on the connector to measure the true impedance of the circuit.
3 items will show air bag light: (for Passenger Seat Occupant Sensor)
1) Seat buckle (OK on my car)
2) Seat occupancy sensor (OK on my car)
3) Battery MRS (safety battery terminal), located on top of battery.
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| Piece of plastic separating the connectors inside the adapter so you can measure it. It's 2 pins inside. But they have a Metal piece that shorts the 2 wires. You have to separate them, like the picture above, so you can measure the resistance. otherwise it will always read short. The correct impedance is about 2 ohms. If it's Open circuit then it's bad for sure. |
Clearing the Airbag light with the Foxwell 510 Elite
Plug into the Car
Run a Diagnostics on the car, it will take about 2 minutes, it's about 24 modules total. For some reason it shows 44 out of 44 modules, but it was actually only 24 modules total
One of the faults will read: Crash safety module ACSM/MRS Fault
Mine was on Module 20
Don't go into Sub menus of Sub menus of Sub menus, just click on the Quick Diagnostics to get these results, from there you can solve this issue.
You can mess up your car really quick if you start messing with the settings, so be warned, just use the simple Quick Scan Diagnostics settings on the first menu you see... that is it. That setting will take you to this screen. Picture below.
Select and go to "READ CODES" by pressing Enter
It will show a list of the problems... My car showed 3 problems, but when I cleared the problems, the same MRS "Safety battery terminal" continued to show ID 93B2
I cleared the codes first, to make sure it was not a Ghost problem from before, that was not cleared from the computer.
Ran the diagnostics again and then only 1 problem showed up... 93B2 : MRS:Safety battery terminal
I know the MRS Safety battery terminal is the big Clucky thing on top of the battery, it has Pyro on it to disconnect the battery in the event of an accident, it looks like this:
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| The Red plastic part distribute the power to other modules, next to it, On top on this pictures is a black plastic part, with thick red wire, that is where the Pyro is, and it has 2 very thin cables attached, pictured below... |
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| Sorry for the "THE" typo, it's been a long day.. lol. |
I disconnect the connector and I measured across it (there are 2 pins populated inside), it measured zero Ohms (0.00 ohms) across the 2 pins, so I know the fuse/ Pyro was OK. So I connected it back and I pushed firmly. Because that connection I believe was bad, and the true source of my problem
When you disconnect the connector, measure with an Ohmmeter on the wires coming off the battery. press on the side of the connector and push it off to disconnect.
I got in the car again and I cleared the code again and it went away... I was very excited when I finally saw the Airbag light finally go off...
Clearing the Code Two Times (2x)
The airbag light went off after I cleared the code the second time, yes you heard right, after I went and checked the Battery terminal cables. Not sure why it didn't work the first time, but it worked the second time for me.
Only mention this because I am sure some of you out there want to try this too. If you go to the dealer to get this repaire, be prepared to pay a lot of money, because they will claim all sorts of things need to be replaced, to get this fixed, you know how it is, they are there to make money by replacing parts in your car.
Little details...
I left out of a few other details, because I am sure you are Knee deep into this issue, and you don't need the little details, but if you do want those details please let me know in the comments below and I will reply to your question there...
I wish you luck fixing this darn air bag warning light...
I hope this was helpful to you!
I post a ton of BMW 330I E90 related content, I have a lot of other posts, check them out, link below to the main page.
Comment below if you have any questions...
Thank again and until next time
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