Airbag Warning Light

[cojonito]

In the passenger footwell there's a black plastic tube which passes through a rubber grommet in the bulkhead into the engine compartment. There are no wires or tubes on the engine side, so I assume that this is some kind of vent or drain. Anyone know what it's for? I used this grommet as a handy way to get some extra wires through the bulkhead, as there is plenty of slack. However, after doing this, the airbag warning light won't go out. I've removed the wires again, but the light is still on. Have I upset something delicate with all the associated poking about? One other factor is that I removed and replaced a lot of fuses at the same time, could this be a factor? I'd appreciate any advice from the experts on the forum, before i have to resort to the local dealer.

[Snoopy]

Two possibilities:

1. You managed to disconnect the passenger airbag connector when you were playing around in the footwell.

2. When removing fuses, you managed to disconnect something that the airbag controller communicates with (ECU, instrument cluster). This logged a fault in the airbag controller, which stays there even when the fuses are back in place.

The second problem is easier to fix than the first - just get a VW specialist or someone with `VAG-COM` to reset the fault code. The first problem would involve getting at the airbag.

The only way to tell for sure is to read the fault code - again, you need a VW specialist or someone with `VAG-COM` to do that.

Your local VW dealer will do it too, but they may charge you...

[tdwindustries]

its more than likely to be the fuses

obviously you should ckeck and check again you have put all fuses back in the right place as a blown/missing fuse would put the light on

unless you were really pulling the wires it probably isnt anything to do with that

[cojonito]

Thanks for the quick reply.

I've checked all the visible connections to the airbag, and they all seem OK. The good news from your comments seems to be that if the system logged a transient fault, the light will stay on until reset, even if there's nothing wrong now. I'll just ask the dealer if he'll reset it for free then, as I've had all my services & MOT there, and they have been quite helpful so far (one of the better ones, going by some of the posts).

Just out of curiosity this time, do you know what that pipe through the bulkhead is actually for?

[tdwindustries]

where is it, the answers no, i have never found it.....

some lights stay on, some go off, i THINK the airbag is serious enough that it doesnt clear itself

[Snoopy]

i THINK the airbag is serious enough that it doesnt clear itself

I already said that style="vertical-align:middle" emoid=":P" border="0" alt="tongue.gif" />

Bear in mind that with the light on, it's a lottery as to whether the airbags will actually work or not. So get it fixed soon. style="vertical-align:middle" emoid=":)" border="0" alt="smile.gif" />

[tshirt2k]

if the Airbag lights on i think the airbag system is disabled. it needs a closed loop. most faults especially intermittent ones put a light on if the fault occurs so many times over a certain period of time. I keep gettin one up - cam position sensor - implausable signal at starting - intermittent. It brings up the engine check light. but only if i start and stop the car quite frequently. then it will clear if i leave it for a while.

[tdwindustries]

whats the code?

[Bikerz]

mothers passat airbag warning light comes on all the time randomly, she took it to vw and said there was no problem air bag would still go off they often do that and it might be somthing to do with the handbrake. Dont understand the handbrake comment, but seems to be a usual VW problem.

[tdwindustries]

i would not be happy with that explanation, the airbag is potentially life saving,,,,,

[Snoopy]

Me neither - totally unacceptable.

[tshirt2k]

Can't remember the code i'll have to scan it again.

[Blackrat]

tshirt2k , how did you get your airbag light off ?

[Snoopy]

Fix the fault and clear the code...

[Blackrat]

replace the airbag ? you gotta be joking

[bossjohnc]

I think TShirt2K always had an airbag cliff - your problem is a little bit more severe! I guess the only way for you to get the light off would be to physically disconnect it...?

[Snoopy]

You'll always throw a fault code even if you remove the airbag controller (instrument cluster expects to be able to communicate with the controller).

The only way to make it go away is to trick the airbag controller into believing that it still has an airbag connected. Instructions (no guarantees) below:

Here's a summary of how to get the idiot light out w/o just removing the bulb from the cluster:

1. Remove the steering wheel and unhook the wires to the airbag. Energize the ignition and the airbag warning light should appear.

2. Use a multimeter to determine the resistance across the driver's side airbag circuit with the airbag reconnected and the ignition energized. Record that value. (If you have any resistors lying around of that resistance bridge those the two airbag wires (airbag removed now) and energize the ignition. The light should be out.)

3. If you don't have any spare resistors, then leave the driver's side airbag connected and fish in the dash until yo are able to remove the passenger's side airbag. Same process as before. Unhook the wires, energize the ignition and test to see if the airbag warning light comes on (it should). When it does, again measure the resistance across the circuit with your multimeter. Record the value.

4. Go to Electronics store (Radio Shack or equivalent) and buy resistors that are the same ohm values as the ones you recorded during your test. You'll probably need to solder on some sort of connectors so that the resistors will be able plug into the airbag wiring. Install everything and

test one airbag at a time so that you can determine which one is causing the light to remain on (if that happens) after you've installed the resistors.

Only caveat I can see in these instructions is that you'll have to clear the fault code after fitting the resistor in order to confirm that the controller is happy.

[Blackrat]

done that

i need to replace the controller unit now, that actually activates the airbag

didnt tshirt buy a wrecked car too ?

[bossjohnc]

I was talking about the light, not the airbag controller!! style="vertical-align:middle" emoid=":P" border="0" alt="tongue.gif" />

[tshirt2k]

y

tshirt2k , how did you get your airbag light off ?

I bought Secondhand airbags and dash and ecu. Have you scanned the controller? it will tell you all probs. I had a battery disconnecter too. But that was replaced another time.

if you have crash data on the controller. you need a new one. don't try to get it cleared 'cos you don't know if it will ever work again. I bought one for £80. bargain . I think it's £300+ from vw. just make sure its got same number on it. and you have to check soft coding too before changing. you may have to recode. you can get airbags quite cheap tho, and it doesn't matter if its from earlier car. Mine were from a '99 model.

[Bikerz]

ok clearly what i said wasnt right. on another airbag note, the airbag is connected to seatbelt thingy so when fittening harnesses u have to dissconect in a certain way or airbag will go off, mechanic told me that.

[Snoopy]

I don't think our ickle Lupos are that sophisticated.

Airbags won't go off unless you drop them (or crash the car!) - you can't set them off by disconnecting things, or by scanning the controller, or anything like that - despite how mechanics love to spread horror stories!

In the more recent/more expensive VWs, the seatbelt latch has a sensor in which detects if the seatbelt is fastened, which determines how (and whether) the airbag deploys in an accident, as well as whether the pyrotechnic seatbelt tensioners fire - if you just disconnect this, you'll throw a fault code.