Airbag light (bit of a panic)...

[FactionOne]

Hi folks,

Long time no speak! Hope you're all well. The world of professional geekery has kept me away for some time but I've got a bit of a panic that's made a quick return more than justifiable!!!

I've got to take the car down for an assessment to do with work tomorrow, and I've been told that it needs to be clear of warnings. I recently fitted a Recaro interior (from an S3) to my baby; but haven't yet done the necessary plug-swapping and stuff to connect the airbags (all the gear is waiting for me at a dealership but I've not been able to get down there either); so I've got resistors in the plugs (maybe .1 ohm out though). When I reconnected the battery it still threw an airbag light though...

So... My query is in a few parts really...

1) Can anyone who's done this before vouch that this is perhaps normal, and after clearing with VAG-COM it will stay gone?

2) Is is safe to say that no A3s were built with the Airbag control unit which goes faulty when scanned with VAG-COM?

3) If clearing with VAG-COM doesn't work, and the problem is persistent, is there any other quick way I might be able to get this light to go out and stay out?

Thanks in advance for ANY suggestions at all /ubbthreads/images/graemlins/grin.gif (no matter how weird and wonderful they are!)

Rob.

 

[imported_gek]

I know when my passenger airbag was disconnected, I could clear the code on vag.com but I couldn't get the light to stay off /ubbthreads/images/graemlins/frown.gif
The error kept returning too.

 

[Khufu]

1. I'm afraid it will keep coming on until you either wire the airbags up properly or fit a resistor across the connections (not sure of value!).

2. Haven't tried the airbags on my A3 but I believe it depends on the year of your car. I have put out lights on an S-reg polo and T-reg Golf without any problems.

3. Take the bulb out /ubbthreads/images/graemlins/frown.gif

 

[FactionOne]

Thanks for the replies guys /ubbthreads/images/graemlins/grin.gif

khufu made a point which is exactly the kind of thing I'm after... Removing the bulb would indeed work, but may be a little fiddly... However, it made me think about 'disabling' things...

In the past when I've had problems with my alarm, I've recoded the module so as to make it think it's just central-locking only. Also a friend with an R32 was spending a day out on a track, and got fed up of having to disable the ESP every time he started it up, so I recoded the module to say it was only an ABS equipped unit.

...So, your friend and mine, Elsa, reports some different codings for the Airbag Control Unit on "Vehicles up to production date CW 26 1999" which mine falls into.

Among the options for things with front & side-airbags and belt tensioners here and there is one you can set to indicate "Front airbags and front belt tensioners" - I wonder if this might effectively bypass the fault being caused by the side airbags being disconnected because in theory, they shouldn't be there?

...Rest assured I'll be off to the garage to check the theory later! *Fingers Crossed*

...Meanwhile any other inspirational suggestions welcome!

Thanks again guys!

Rob.

 

[Khufu]

never heard of that before - keep us informed!

 

[Markb]

Sounds interesting as I might need to do this with mine if I get aftermarket front seats.

Keep us updated!

 

[FactionOne]

Right a bit of an update...

I'm convinced that the theory I had of recoding the module is valid...

When I scanned the module I found the code it was set with matched the list on Elsa as "Driver and Passenger front and side Airbags, with front and rear Belt Tensioners"

...However, I had forgot one of the ten commandments of VAG OBD - "Thy module will do precisely nothing while a fault code be admidst the memory"

So, I'm still pretty confident you could confuse the controller into putting the light out, but of course you have to clear the light to be able to do it first. It's also my public duty to point out that if you did this you would also be without belt tensioners in the rear; so any rear passengers would be at the mercy of the inertia-gear only in the event of an accident (I guess the module will not attempt to fire the tensioners if it's under the impression they're not there).

...So, I started to consider other options... khufu's idea started to become very appealing... I hit Elsa to check how to remove the clocks before I charged outside with my tools, and happened to think of checking for a page describing how to change bulbs inside the clocks...

"All the lamps inside the Dash Panel Insert are LED type; with the exception of three. If any of the LED lamps are to fail replacement of the Dash Panel Insert is required" (not quite verbatim, but you get the picture)... It goes on to list the possibilities, but guess what; ABS isn't one of them.

Below is an image of Fritz flicking the bird.

So, if I want to "disable" the light in a hurry (postponed for a short while), it looks like I have one option... 32 way connector into clocks... one little V+ wire... one pair of snips /ubbthreads/images/graemlins/grin.gif

...Unfortunately it looks like that's going to be the only option for a "quick-fix"; and of course I can repair it after the assessment is out of the way; and given a bit of time over the Christmas break I'll either a) confirm my theory for modifications to allow me to connect the airbags and do it, or b) plug the old airbags in, clear the fault code and then recode the module.

So to Mark and anyone considering aftermarket seats, or seats with different Airbag plugs; you COULD in theory do the recode method if you chose to, but you'd have to do it BEFORE you unplugged your original seats.

Well, the problem's still there for the time being, but I feel enriched because I can't say I haven't learned anything!

Regards,

Rob.

 

[Markb]

Have you got any further with this?

 

[FactionOne]

Hey Mark,

Sorry I didn't post an update to this one; lately most of my thoughts about my car have been about getting the audio system sounding like it did a couple of months ago (got some REALLY annoying headaches with it at present /ubbthreads/images/graemlins/confused.gif)

Right, in the end I had an attack of conscience shortly before I took the snips to the loom for the dash-lights... I figured I've spliced enough wires on my baby so far, and to be honest while I would be totally happy and confident with a 're-joined' wire looking after the airbag light illumination, I wouldn't like to know there is a 'bodge' on the airbag warning system when I pass the car on....

So, having thought about that, and having dug my old front-seats out of the shed with considerably less fuss than I was expecting, I quickly threw the fronts back in and just cleared the fault code.Later though, I did give the re-code a go. I left the original seats in, and coded the controller to think it was commanding front airbags (driver and passenger), and front belt-tensioners (obviously leaving the inertia-switches in the belt spools and the obesity of front-seat occupants being responsible for stopping those in the back from coming forwards).

At this point I dropped my Recaros back in (disconnecting the battery during the swap so as not to have any accidents); and when I turned on the ignition I got no light... I didn't go out for a test-drive, or do many ignition-cycles, so I can't say 100% that the light was out and not going to come back on, but it looks pretty good... Also, my theory might also be supported by the fact that as soon as I re-coded the controller to the correct value (covering both front airbags, both side airbags and all the belt tensioners), the warning light came on again.

...So all in all, it looks like it's worth a go as a quick or temporary fix to the pesky airbag light issue, of course as stated (a lot) you will have no rear belt-tensioners, so the ideal solution would still be to actually connect the airbag wiring to the fronts - on that score I've got what I hope is a sound theory regarding the wiring of new-style airbags to old-style controllers, but I need to do some more checking (hopefully between myself, an auto-electrician contact of mine and a slightly information-leaking member of Audi staff, we can get it figured out without much more delay)....

Hope that helps mate,

Rob.

 

[Markb]

I wasn't planning on having any rear seats anyway. So that would not really bother me, but then again if I put the rears back in I want the seat belts to work.

Will be interested to see if your airbag wiring solution works.

Finally why didn't the resistor work? As I am sure other members have used these before. Also Recaro give you resistors with the subframes.

Fitting S3 seats

Says use a 4.7 ohm resistor

Mark.

 

[rojocho]

just to throw a spanner in the works, will this effect mot, as abs light must come on at start up, and disconnecting a bulb would stop this. is it same for airbag light, does it need to show and go out?

 

[FactionOne]

Mark:

Yes mate, I've got that thread in my favourites list! /ubbthreads/images/graemlins/grin.gif I did give the resistor method a try when I first installed the seats; but when I got to CPC (my local electronics warehouse (and about the size of wembley)), they didn't have any at 4.7ohm in stock; I tried with 4.6, thinking the tolerance probably isn't that fine.

Anyway, the fault code I got was logged for "resistance too high" - of course that could technically mean that it was disconnected, but a) I'm pretty certain I'd made good contact in the plugs and added insulating tape to hold it in there nice and tight; and b) a lot of the modules on the car will report "circuit open or short to ground" if something's physically disconnected, so I'm confident that's not the cause.

Then it raises the question of the resistance being too high, I haven't actually tried with lower values (yet). I'll also be taking a multimeter to one of the 4.6s' I was sold just to check...

rojocho:

Are you sure airbag lights are checked on the MOT? *ahem* A friend *ahem* of mine recently had his A3 in for MOT with a half-connected Recaro interior and a REALLY bright constant Airbag warning light and it passed with flying colours?

Regards,

Rob.

 

[Khufu]

airbags arent checked for MOTs only the ABS warning light fails the test.

 

[benk]

When I had an MOT done last month, the guy said there is talk of bringing airbags into the test, but as khufu says, they're not in yet.