Air bag warning Light

glenndaleuk1 · Unread post by **glenndaleuk1** » 17 Mar 2008, 12:18

Hi All
My air bag warning light is flashing for a short while then stays on. Can anyone give me a remedy for this.
The vehical is a 1997 Xantia 1.9tdi vsx. Is it likley to be expensive ?

Thanks
Glenn

Unread post by **RichardW** » 17 Mar 2008, 12:59

Most likely the connectors for the seat belt tensioner under the front seats. Unplug them a few times with some contact cleaner / WD-40 should sort it. For a few days anyway!

glenndaleuk1 · Unread post by **glenndaleuk1** » 17 Mar 2008, 14:39

Hi Richard
I just tried your suggestion, unfortunatley it didnt work. Any more ideas ?

Thanks
Glenn

MikeT · Unread post by **MikeT** » 17 Mar 2008, 15:35

As advised, the most common reason is old/worn connectors not making good contact. Cleaning sometimes works as it did for mine but soon returned again so I just soldered the wires instead. Best repair is to fit new connectors so they can be detached should the seats need to come out.

np · Unread post by np » 17 Mar 2008, 19:52

I had this on and off with my TD VSX.If its not the underseat connectors its more than likely the connector in the steering wheel.The airbag and then the steering wheel have to come off but its quite easy.I had a new one wich lasted a year or so till the light came on again.I then got a few spares from the scrap yard with worked for a while.
Once fixed the light will go out as normal.
I think i posted how to go about the job a few years back now,try doing a search for full details.

glenndaleuk1 · Unread post by **glenndaleuk1** » 18 Mar 2008, 08:18

Thanks Guys for the advice.
I dont feel confident enough to tackel taking the steering wheel and air bags out myself. So am looking for someone to check it out for me. Can you tell me is it an MOT issue because it`s due in a few days. Thanks

Unread post by **CitroJim** » 18 Mar 2008, 09:00

glenndaleuk1 wrote: Can you tell me is it an MOT issue because it`s due in a few days.

Yes it is. As I understand it, the airbag light must go through the correct sequence for the MOT tester to be content. The light must be seen to come on at ignition on and then go off after a short while. Taking out the bulb is not an option. An MOT tester woth his salt will spot it.

Taking the steering wheel off is not that difficult and the airbag is not dangerous as long as you observe all the handling precautions. If you do go in, allow the system to discharge fully for at least 10 minutes after disconnecting the battery and handle the airbag with care at all times.

DickieG · Unread post by **DickieG** » 18 Mar 2008, 10:05

I don't think that's correct Jim, AFAIK one of the quirks of the MOT is that air bags are not subject to test, indeed even if a seat belt pre-tensioner has been triggered it is only an advisory. I've also had a look through the following links and can't find any mention of airbags being cause for failure.
http://www.motuk.co.uk/default.asp
http://www.direct.gov.uk/en/Motoring/Ow ... G_10016070

Unread post by **RichardW** » 18 Mar 2008, 10:07

Sorry, Jim, you're wrong for a change....

Airbag is not currently part of MOT - ABS is (but the only test is that the light behaves as expected, as you described). You might get an advisory on the air bag light, but it won't fail.

It might be worth forking out the £40 to a dealer to get the codes read to see what the cause is, before you go chasing your tail - there are possibly 2 airbags, the clock spring, the seat belt tensioners, and the pass a/bag off switch to go at after all!

You did try the connectors under BOTH seats I assume.....

Unread post by **CitroJim** » 18 Mar 2008, 10:33

RichardW wrote:Sorry, Jim, you're wrong for a change....

I'll just get my coat and stand in a corner for the rest of the day

That is quite a quirk. I honestly always thought it was a failure point but I'm very happy to be wrong on that

glenndaleuk1 · Unread post by **glenndaleuk1** » 18 Mar 2008, 11:50

Sorry fellas I didnt mean to start a war.
I just drove it about thirty miles to a citroen specialist and it seems to have reparied itself on the way, same happpend with the ABS light last year. It was on for about three months then went off and has been ok ever since. Bloody clever these citroens. Might just keep it a bit longer.
Thanks All

jgra1 · Unread post by **jgra1** » 18 Mar 2008, 12:02

sorry to hijack, glad yours is ok Glenn

My side air bag light and main airbag are on now. I was expecting this tho.. From memory, thie airbag is on continously and the side bag flashes, but it could be the other way around..

The reason the side airbag lights up is that my new interior, although M2 was too early for side airbags, and the old interior had them,..

1) how can I extinguish the now obsolete side airbag light (bulb out or fuse?) or trick the car to think the side airbag system is ok..

2) would the warning light for the side airbag cause the main airbag warning to come on, seems likely ? or is there another airbag issue now as well as the missing sidebags? (the lights weren't on with old seats)

thanks
John

Unread post by **CitroJim** » 18 Mar 2008, 17:10

jgra1 wrote:1) how can I extinguish the now obsolete side airbag light (bulb out or fuse?) or trick the car to think the side airbag system is ok..

John, I've been thinking about this. I may be way out here but this may be worth a shot..

The airbag ECU will be doing a test to see if the bags are present and although I've tried to find out, actually how this is done is not clear. However, I believe they work on the principle of a small heating element (firing coil) firing the pyrotechnic charge. This being so, the ECU will check the integrity of the firing coil by measuring its resistance in much the same way as the ABS ECU checks its sensors. It will look for a specific resistance and will detect a short or open circuit as a fault condition.

I'd try to measure the resistance of this coil on a scrap (but otherwise good) airbag and try a normal resistor of the same value in place of the airbag and see if the light then extinguishes. I'd expect the resistance value to be quite low (10s of ohms) and quite critical as far as the substitue resistor was concerned.

If this does work, use fairly high-wattage resistors in the final solution as if the airbags do deploy, small resistors may burn and possibly start a fire.

I'd expect any airbag problem to light the main airbag light.

A little caution. If you do take a resistance measurement on an airbag, use a good digital meter that feeds a very small current to the airbag. Using something like an AVO Meter or any old-style analogue meter on low Ohms ranges can push quite a current out and possibly cause the airbag you're testing to deploy. Perhaps this exercise is best carried out in a scrappy taking care just in case the bag does go off. Wear ear protection too.

As I say, don't take this as gospel in any way. This is simply me thinking and taking a stab at it.

jgra1 · Unread post by **jgra1** » 19 Mar 2008, 09:41

Jim Many thanks..

I suppose I could try a range of resistors on the wiring that would have plugged into the seat.. and see if any extinguish the light..

I am due a visit to the wreckers soon anyway, so may look for an airbag to test.. I guess it doesn't matter what it's from..

I have a decent digital multimeter..

thanks again
J

ken newbold · Unread post by **ken newbold** » 19 Mar 2008, 09:51

Just had the same problem. Turned out to be a broken wire on one of the underseat connectors. Not too easy to see under there, but now fixed.