An Audiophile fix for airbag light

[P2C4]

I have a 1999 C4 which I purchased 4 months ago with 37K miles. Ever since I've had the car the airbag light has been on. I read many threads on this site about the airbag light and what it means, including the technical bulletins. (Thanks Loren.). The local dealership wanted $600 minimum to fix the problem.

Here's the odyssey. A couple months ago I bought the Durametric software and cable and used it to read and reset the error codes or fault codes and had numbers 45, 46, 47 and 48 which relate to the airbag light and the seat belts on both the driver and passenger sides. The message associated with the numbers was drive or passenger side "belt buckle may have been unplugged at some time, check connector to belt recepticle."

So, I reset them. And they'd come back, particularly the passenger side. They'd come back on randomly within minutes or a few hours of a reset. So I prepared to purchase new seat belt buckles.

Then I had :lightbulb: an idea. I didn't recall reading any thread here about cleaning the contacts. So, I sprayed both belt buckle recepticles liberally with DeoxIT D5 (using the small red tube to direct the spray), and I elevated only the passenger seat and sprayed all the electrical junctions I could find where wires from the seat belt connected. I'm used to being fussy about electrical contact cleaning for improved sound in my stereo and home theater system (yes it really does make a difference, and yes sometimes you can hear a difference, particularly in the high frequency sounds).

Well it seems to have worked. It's been 3 weeks now. No airbag fault codes. I drive my C4 every day, usually 80 miles or so. My daughter is working with me this summer, so between us we operate each buck at least half a dozen times a day. And we've had no problems. (Knock on wood.)

A word of caution. DeoxIT D5 is highly flammable, and the stuff will ruin the finish. (Keep a wet rag around to wipe off any over spray.) The spray nozzle on the 5 oz can be adjust to three positions. I used the lowest setting. This stuff will also clean up noisy switches in radios and other electronics. Usually it works best if you spray it on and then let things sit for 5 minutes, and then wipe off the contact, and then treat it with DeoxIT Gold. I didn't wipe any off, and I haven't treated my seat belts with any contact preservative (yet).

:unsure: I hope I'm not just temporarily lucky, and I hope this helps someone else.

[Kim]

Thanks for a great tip. I'm filing this one away for the future .... as I've been dreading the infamous airbag light ever since I joined RennTech and started reading of all the problems .... and the expensive dealer fix.

[Loren]

Sorry, but I think that the fix is likely temporary. The connectors corroded and that is why Porsche replaced them with gold contact connectors.

[Kim]

Sorry, but I think that the fix is likely temporary. The connectors corrode and that is why Porsche replaced them with gold contact connectors.

Loren, I think that is his point .... oxidation was the cause of the corrosion, and this spray, DeoxIT, is an oxidation clearner and preventer. We won't know for a while, I guess, but I do have some experience with oxidation interfering with electrical connections, both low voltage and the household type. Using an anti-oxidizing agent as a preventative is an established practice in both fields.

[P2C4]

I think Kim's right. It might be a temporary fix. But if it's like audio equipment, you simply re fix it. And then preserve it (which I haven't done yet) with the DeoxIT Gold G5. I've got a can, but haven't used it yet (still pursuing the experiment).

Some audio high end equipment employe gold plated connectors on input/output jacks. They still benefit (a little) from a regular annual cleaning.

We're a little more than 3 weeks into my fix now with no problems. And the fix took about 30 seconds, or maybe 2 minutes if you count resetting the codes. So, if buckle replacement takes 2 or 3 hours . . . well, I think I could fix this pretty often and be time and money ahead. As I read this message board it seems Loren is almost never wrong. Let's hope this one surprises him.

I'll update this post if this fix ever unfixes.

Edited August 12, 2006 by P2C4

[philhan]

Hi guys:

Ok I just got the dreaded air bag warning light last night and it's bugging the crap out of me everytime I drive because I get fixated on the red glow.

So I did have the dealer fix the airbag and seat belt under warranty a couple of years ago and it's been fine. So I'm assuming I have the updated gold connectors that Loren is talking about so after reading this post I want to try and clean them myself.

Questions:

Where are the sensors located? Do I have to remove the seats?

Is there anyway to clear the code without using the scanner? Can I disconnect the battery for a couple of minutes to clear the code?

Many thanks

Phil

[Loren]

Where are the sensors located? Do I have to remove the seats?

The connector (not sensors) are under the seats and connect to the seat belt buckles. You will need an E12 (external) Torx socket to remove the seat(s). It is best to disconnect the battery so you don't short anything out.

Is there anyway to clear the code without using the scanner?Can I disconnect the battery for a couple of minutes to clear the code?

No, and a regular scanner won't do it either. You will need the Durametric Software or PST2 (or PIWIS) to reset the airbag light. The Durametric Software runs about $250, and the PST2 (used) about $3600 and the PIWIS (new) about $18,000.

[P2C4]

I didn't remove the seat. I just gave each buckle a pretty good shot around the insides edges (with a rag rapped around the outside of the buckle to catch any over spray), and under the seat passenger seat a good shoot into each wire entry position in the plastic junction box (about two inches square) where the wires from the belt buckle lead. Don't forget to attach the little red tube to the spray can.

[philhan]

I didn't remove the seat. I just gave each buckle a pretty good shot around the insides edges (with a rag rapped around the outside of the buckle to catch any over spray), and under the seat passenger seat a good shoot into each wire entry position in the plastic junction box (about two inches square) where the wires from the belt buckle lead. Don't forget to attach the little red tube to the spray can.

Ok I was finally able to locate a dealer in Los Angeles who sold this stuff....if anyone is interested West LA Music is an authorized dealer. I sprayed the seat belt and the connectors underneath the seat. Nothing yet. I did order the Durametric reader, it seems like a good investment and I'll clear the codes when I receive it hopefully later this weeks. I will post an update to see if this solution works.

Thanks for the tip.

Phil

[fujikomine]

I just had the airbag light problem and had a local dealer diagnose and replace the driver's side buckle. I've had the same problem in two other bimmers in the past 6-8 years so it's a manufacturer issue...I'm betting they all ultimately source the buckle system or components from the same european manufacturers. Wish I saw this topic prior to last week...would have saved me $528.

[philhan]

I just had the airbag light problem and had a local dealer diagnose and replace the driver's side buckle. I've had the same problem in two other bimmers in the past 6-8 years so it's a manufacturer issue...I'm betting they all ultimately source the buckle system or components from the same european manufacturers. Wish I saw this topic prior to last week...would have saved me $528.

Update:

Sprayed the seat belts, and all connectors underneath the seats two days ago with Deoxit D5. I received the Durametric reader today. Airbag fault code is 45: Driver side seat belt buckle unplugged. Checked everything underneath and everything looked ok so I cleared the code and so far it has not come back on. So everything so far is ok.

GREAT TIP :notworthy:

[P2C4]

After a little more than 6 weeks my airbag light came on -- fault code 45 drivers seat belt. I use my car alot, and the driver buckle probably had about 150 connections and 150 unconnections in that time. I think the light came on when the seat was adjusted -- rolled backward-- more than usual to accommodate the long legs of my son. That may have pulled on the wire connections under the seat from the seat belt. That's my theory.

I sprayed the buckle with DeOxit5, and that didn't keep the light from coming back on. So for the first time ever, I sprayed the connections under the driver's seat. You may recall from my above post that initially I only sprayed the wire connections under the passenger seat belt. And I must apologize. It was more difficult to get at the connection under the driver's seat because apparently it has a little plastic guard at the front of the seat near the carpet. My passenger seat is missing that part. The guard had to be pulled forward to be rmove so I could see and spray the seat belt wire connections under the seat. It took me 10 minutes and a mirror to figure out how to pull that guard off. Getting it back on was easy. Spraying to 20 seconds.

The airbag light has now been off for 9 days with my continued heavy use of the car. I still need to spray all the connections with ProGold.

[bwillis]

I just used an electronic contact cleaner (CRC QD) to spray the receptacles and under the seats - switched the light off with Durametric - all is well - light hasn't come back on. This is the same stuff I used to clean the MAF when my CEL came on (advice per Mike Focke) - you can get it at Ace Hardware (about $4).

Bob Willis

1998 Boxter 986, 5-speed Manual, 90,000 miles.

[P2C4]

I just thought I'd add that both seats have so far remained fixed. I drive the car every day (18K mi/year).

[P2C4]

On July 4, 2007, the passenger air bag light came on. That seat gets much less use. I reset the light with the Durametric software (thanks for tipping us on to that Loren), and sprayed the connection under the seat with deoxit5 and the light is back out, likely for another year.

[zee]

On January 4th, 2008 the airbag light came on on my 1999 C4 Cabrio. I i sprayed everything with deoxit5 as recommended and then had the light reset at the dealership. Its been almost 2 weeks with about 500 miles driven the airbag light hasnt lid up yet. I sprayed both the seat buckles and under the seats. Hope that it stays that way.

[siddharth]

On January 4th, 2008 the airbag light came on on my 1999 C4 Cabrio. I i sprayed everything with deoxit5 as recommended and then had the light reset at the dealership. Its been almost 2 weeks with about 500 miles driven the airbag light hasnt lid up yet. I sprayed both the seat buckles and under the seats. Hope that it stays that way.

So if I simply clean all contacts will the light eventually go away (assuming it's because of oxidized contacts)? Or do I have to actively do something more to turn off the light? I just got the airbag light during my evening ride, so it's annoying the hell out of me ...

What's the cheapest way to turn the **** light off??

[Loren]

On January 4th, 2008 the airbag light came on on my 1999 C4 Cabrio. I i sprayed everything with deoxit5 as recommended and then had the light reset at the dealership. Its been almost 2 weeks with about 500 miles driven the airbag light hasnt lid up yet. I sprayed both the seat buckles and under the seats. Hope that it stays that way.

So if I simply clean all contacts will the light eventually go away (assuming it's because of oxidized contacts)? Or do I have to actively do something more to turn off the light? I just got the airbag light during my evening ride, so it's annoying the hell out of me ...

What's the cheapest way to turn the **** light off??

Find someone near you with the Durametric software, a PST2 or PIWIS tester.

[1schoir]

On January 4th, 2008 the airbag light came on on my 1999 C4 Cabrio. I i sprayed everything with deoxit5 as recommended and then had the light reset at the dealership. Its been almost 2 weeks with about 500 miles driven the airbag light hasnt lid up yet. I sprayed both the seat buckles and under the seats. Hope that it stays that way.

So if I simply clean all contacts will the light eventually go away (assuming it's because of oxidized contacts)? Or do I have to actively do something more to turn off the light? I just got the airbag light during my evening ride, so it's annoying the hell out of me ...

What's the cheapest way to turn the **** light off??

Sid:

Before you get the light turned off, be sure to check and record the fault code.

If the light keeps coming back on, you will have to resort to more drastic measures. The repair procedure which consists in part of improving the grounds under the seats, is covered by a TSB.

Regards, Maurice.

[Kevin M.]

I can't believe know one has suggested pull the instrument cluster and pop the bulb out :)

[siddharth]

I can't believe know one has suggested pull the instrument cluster and pop the bulb out :)

You know, I thought about that ... but then when starting the car, it would light up all the lights except the one without a bulb. Plus I don't know if the car computer would get upset over a missing bulb and log a whole bunch of errors against that ...

[siddharth]

I can't believe know one has suggested pull the instrument cluster and pop the bulb out :)

You know, I thought about that ... but then when starting the car, it would light up all the lights except the one without a bulb. Plus I don't know if the car computer would get upset over a missing bulb and log a whole bunch of errors against that ...

Ok, so I just got a call from the dealer. He said that they need to replace the

1) seat belt clips (the part fixed onto the seat, neat hips)

2) and the wiring harness under the seat

For both drivers and passengers side to fix it. Parts + labor = $870. Does that seem ok or a bit high ??

Also, is it necessary to replace both sides or just one side, the faulty side, would be ok? I didn't confirm yet, but I think its unlikely that both sides would go out at the same time, eh?

Edit: Sorry, but last question: Assuming I buy the durametric tool, does anyone know how easy/tough this repair would be a DIY?

As always, thanks!

Sid

Edited March 27, 2008 by siddharth

[Loren]

I can't believe know one has suggested pull the instrument cluster and pop the bulb out :)

You know, I thought about that ... but then when starting the car, it would light up all the lights except the one without a bulb. Plus I don't know if the car computer would get upset over a missing bulb and log a whole bunch of errors against that ...

Ok, so I just got a call from the dealer. He said that they need to replace the

1) seat belt clips (the part fixed onto the seat, neat hips)

2) and the wiring harness under the seat

For both drivers and passengers side to fix it. Parts + labor = $870. Does that seem ok or a bit high ??

Also, is it necessary to replace both sides or just one side, the faulty side, would be ok? I didn't confirm yet, but I think its unlikely that both sides would go out at the same time, eh?

Edit: Sorry, but last question: Assuming I buy the durametric tool, does anyone know how easy/tough this repair would be a DIY?

As always, thanks!

Sid

For a difficulty level read the TSB.

If you have a Durametric tool it will tell you exactly which belt buckle needs replacing. You could wait on the other and replace only the one that gives a fault.

[1schoir]

Ok, so I just got a call from the dealer. He said that they need to replace the

1) seat belt clips (the part fixed onto the seat, neat hips)

2) and the wiring harness under the seat

For both drivers and passengers side to fix it. Parts + labor = $870. Does that seem ok or a bit high ??

Also, is it necessary to replace both sides or just one side, the faulty side, would be ok? I didn't confirm yet, but I think its unlikely that both sides would go out at the same time, eh?

Edit: Sorry, but last question: Assuming I buy the durametric tool, does anyone know how easy/tough this repair would be a DIY?

As always, thanks!

Sid

Sid:

Assuming you already have the fault code that indicates it's the seat belts (or one of them), you can do the repair without the Durametric, although you will need it to reset the light and it's an excellent tool to have if you DIY.

Once you decipher the language in the TSB, it's a very straightforward DIY. As long as you know how to solder, and can follow directions, it should take no more than about 3 hours to do both sides. The dealer can do it in less than 2 hours if they have done it before. Total parts cost is less than $150 IIRC.

Regards, Maurice.

[siddharth]

Ok, so I just got a call from the dealer. He said that they need to replace the

1) seat belt clips (the part fixed onto the seat, neat hips)

2) and the wiring harness under the seat

For both drivers and passengers side to fix it. Parts + labor = $870. Does that seem ok or a bit high ??

Also, is it necessary to replace both sides or just one side, the faulty side, would be ok? I didn't confirm yet, but I think its unlikely that both sides would go out at the same time, eh?

Edit: Sorry, but last question: Assuming I buy the durametric tool, does anyone know how easy/tough this repair would be a DIY?

As always, thanks!

Sid

Sid:

Assuming you already have the fault code that indicates it's the seat belts (or one of them), you can do the repair without the Durametric, although you will need it to reset the light and it's an excellent tool to have if you DIY.

Once you decipher the language in the TSB, it's a very straightforward DIY. As long as you know how to solder, and can follow directions, it should take no more than about 3 hours to do both sides. The dealer can do it in less than 2 hours if they have done it before. Total parts cost is less than $150 IIRC.

Regards, Maurice.

Dang ... they just called back and mentioned that the computer flagged BOTH sides as faulty. Plus I'm moving over this weekend (i.e. no time) and have a prospective buyer for the car (going back to business school). Looks like I'm going to have to ask them to do it for $870 ... this sucks. Man, this airbag light came on at the worst possible time ...

Loren, what is the TSB number?

Maurice, do you know which place to buy the parts from? Trying to see if I can REALLY squeeze this in ...

Edited March 27, 2008 by siddharth