Airbag Connection Fix
 

Hello all, I replaced my front driver door carrier, and like a moron, disconnected the airbag....now I have a fault code. I have plugged the airbag back in, turned on the car, and gone through my Foxwell 510 to reset the light - when I hit erase code, the light turns off, blinks on and off, then comes back on to stay.

Any idea why it is not turning off through the system here? I've been following what various YouTube videos say to do when going through, but my blinks off and then back on again. Any help is appreciated!

Tim

Erase the code, disconnect the battery for about 30 minutes and reconnect the battery.

Dumb question but when I erase the code the light comes on 20 seconds later. Do I have to sprint to unhook the battery or does that not matter in terms of timing

Does it tell on the code if it's for too high or too low resistance? Did you possibly break the plastic splices on the locking part of the airbag connector?

Yes I do think I broke the splices. It’s odd because the connection isn’t loose, it takes a good tug to remove, but maybe it’s because the clip is not forcing the connection tighter?

Just to try to help by confirming what should have happened:

disconnecting the airbag while the car battery is still connected ==> yes, that properly sets the airbag light which then remains until it gets reset with a special tool such as the Foxwell. BTW I do this just about every time I open up a door on my 2001 3.0i. I know the light will be set, and successfully rely on the Foxwell (and previously a different, airbag-reset-only tool)

Using the Foxwell to reset the airbag light ==> yes, that should clear it, not requiring any other steps such as battery disconnection.

So my thinking is that since the Foxwell reset is not holding, you must have something broken there. So reading the actual code might help confirm, figuring out what you may have snapped, etc.

One additional random fact that may or may not be useful ... That special-purpose airbag tool (eBay, $20, Chinese, called something like 8800) I had before I got the Foxwell worked very reliably, but every single time, it took two reset cycles for the reset to work. I never figured out why, and did not worry since it always worked on the second try. I don't think my Foxwell NT520 Pro has this issue. But you might try doing the reset twice in a row to see if anything changes (if you have not already done so). Just a guess. Good luck.

The purpose of those thin plastic tabs on the locking part is to separate shorting splines from pins on the airbag side connector.

https://www.e46fanatics.com/attachme..._b-jpg.318332/

https://www.e46fanatics.com/attachme..._1-jpg.318311/

https://www.e46fanatics.com/attachme..._2-jpg.318312/

Ok, just ordered a new door harness off ebay so I can pull the spline/clip thing for the airbag connector. Hopefully that secures the connection properly and i can reset without issue.

Help, I am still in airbag hell. The door harness came, I swapped the airbag connection clip, started the car up.....and the light is still on. Go to reset via the Foxwell, it goes off, blinks on, then off, then comes back on permanently.

I also disconnected the battery for awhile, hooked it back up, airbag light is still on. Any other ideas?

Tim

What SRS code is your foxwell reporting when you scan it?

use some needles to either backprobe each side of the connector or into the wires themselves to make sure the connection actually is secure on both leads..

most DMM use a 9v battery so i would not recommend doing a direct read of the airbag, but many airbags can be 'deleted' by using a 2Ω resistor in place of the airbag to clear codes; i have a feeling BMW does actual 'talking' to the airbag to tell if it's 'the right one' so that won't work.

+1 on exactly what error and also; sometimes you can't clear codes when the engine is running and sometimes you can't clear codes when it isn't so try both ways

i just found a thread where soembody had a similar problem and shared screen shots from INPA where it showed 'detonation ckt is too few' the acceptable range seems to be from about 1Ω to about 7Ω.

Apparently you can measure the Ω. see this: https://youtu.be/uAklUlvAIrs

notice that the airbag in the video has a shorting bar to prevent accidental detonation when the airbag is not installed, possibly the connector does the same thing and the repaired connector is not doing the job of opening the shorting bar (in which case you'd read a short across the wires (pin through the insulation).

If i did this test, i would not be 'right in front of' the airbag in case by some chance enough of the 9v battery in the tester got through the leads and sets off the airbag.

I was trying to illustrate this shorting splice in my previous post. If the plastic parts of the plug locking don't separate the shorting splices from the pins there will be active fault code for too low resistance.

@Clavurion -- Haha, you're messing with the entertainment! If you would have waited a bit longer andrewwynn probably would have taken credit for the fix as well! ;)

Somehow I missed your entire post that was explained in the video. I saw your pics (which were about 10" square in my web browser, might want to size down on the future; I always set to medium size when uploading.

Only if credit is due. Eg; I explained how to actually test the connector, not just describe how the connector works (which I didn't see the post from clav). Clav full credit to note the connector shorting bars before I even knew they existed.

The question is: how to debug and solve the problem. If my suggestions lead to the correct diagnoses and lead to the solution than, yes of course I'll accept the deserved thanks from the OP.

No problem seeing Clavurion's post. All pictures appeared to be fine on my web browse but I'm on a MacBook.

When I go into the sub menu and the Airbag, it reads "5 - MRS: Side airbag, front left" Clear code, it goes off, blinks on, blinks off, then comes back on permanently

That would infer that the fault still exists- most likely the shorting bar in the connector as discussed above.

I tried clearing with just the key in the ignition and car not on, but no dice. Are the connector and locking tab one piece? Is there a tab or coding fix to correct this....I am trying to sell the car in near future and would love for no lights to be on the dash.

No way to code out an error like this. The only fix is likely to be to ensure the connector is working as it should.

Have a read of this thread on how to repair the connector (assuming your's is broken - and yes, I know you have replaced it but it seems like you may now have two broken connectors... :rolleyes: )

https://www.e46fanatics.com/threads/....680542/page-2

Airbag Connection Fix
 

If you look at the video I sent how to test shows how to remove the shorting bar and I believe you would be able to do that on my damaged connector and get it to read correctly

If that works I would just put a very obvious Leo on airbag self annotating that the shorting bar is not functional so you can be conscious with that airbag if it’s ever unplugged

So my 6 year old apparently shoved the shorting back in a the center console, which, great! I installed it on the connector, clipped it in, turned the car on, and the light is still on. I used the Foxwell to reset the light, and same deal, it blinks off then on again. I unplugged the battery for an hour, plugged it back in, light still on.

This is driving me batty. I guess i can fashion two posts out of a credit card and try to use that because maybe the shorting bar is broken and not doing what it should? I have no idea at this point.

Could there be an electrical fault within the airbag? Could order a cheap ebay bag to test. Not sure if you could or would want to risk doing electrical testing on the bag itself.

From what I have determined it is safe to test on the airbag. If I couldn’t get the connector to work I would just cut the connector and spice making sure that the positive and negative are the same.

The car is measuring the Ω of the airbag every time you turn the car on if you use a digital ohmmeter you’re gonna be perfectly fine. For safety sake obviously don’t in the airbag at your face when doing the test. Follow the video that I linked above the guy shows you exactly how to test the airbag including how to break the shorting bar using tiny pieces of a straw. You could leave those tiny pieces in once you confirm the measurement comes out correctly. I would put a label on the connections so future mechanics including yourself will be alerted to the case.

Thank you all for the tips - the cut credit card tab methodology worked and I no longer have a light on my dash! Appreciate the time and effort to point me in the right direction here.

Awesome!

So the problem the whole time was the tabs were "stuck" in the shorted position?

every figure this out?
 

Did you ever get this sorted? I'm having the same issue.

He did sort it - see post #26 above. :thumbup: