Airbag light - with a twist

Some time ago my Passat was scanned at a workshop and returned a 00588 32-10 error (driver side igniter N95 resistance too high - intermittent). The shop was able to clear the codes and switch off the warning light, but it came back on shortly. I assumed then, that the cause was a bad clockspring, which indeed had a crack. I fixed the clockspring shortly thereafter, but did not have time to go back to the workshop so I continued to drive with the airbag warning light on for a little while. This week I got access to a laptop with Vag-Com, so I went and tried to clear the codes. The 588 error unsurprisingly was still there, so I cleared it, but the warning light stayed on. I went for a short test ride, exercised the steering wheel a lot and scanned the airbag controller again. There were no errors stored this time, but the warning light is still on. This leaves me puzzled. I played a bit with measuring blocks, but the status of all four igniters is correct (airbags and belt tensioners), also the supply voltage is OK.

To summarise:

controller is a 6N0 909 603 H and identifies itself as an AIRBAG VW2 V00;
coding is 00072. Workshop code: WSC 05311.

No faults found.

Warning light is on and does not even flicker, after turning the ignition it just goes on and stays on.

According to measuring blocks values everything is OK.



Is there an extra step besides clearing the codes to get the warning light off?

Please, help.
W.

Ok, this gunna sound doumb but...

Perhaps cause a code to be set, IE unplug the airbag and turn the ignition on. Then clear it with vag-com. The light should go out for just a seccond. If it never goes out, perhaps you have an eletrical problem with the light itself?

I may be totally of on this...

-Jason

The airbag/abs warning light has a fancy little circuit inside it, so it is highly possible that it could be faulty and making the light stay on. It is also about a $200 part.

One common problem is related to heater core failures. The airbag module is sunk deep in the carpet below the heater box. If your car has had heater core failure, coolant may have spilled down into that cavity and gotten in the orange plastic connectors on the module. Unfortunately it would require a major effort to even investigate this possibility, but it is a common occurence. If you're download speed is decent, you can see pictures of my friend's car with this problem here, about halfway down the page beneath the headlight pics:
http://forums.vwvortex.com/zeropost?cmd=tshow&id=2251793

compu_85: I unplugged driver side airbag, the code showed up as expected. Reconnected and cleared the code, but the warning light stayed on. It never went off during the Vag-Com access. But I noticed one thing, approx. 3s after turning ignition to on there is a brief period of very slightly lower light intensity in the airbag warning light. One has to expect it and really concentrate to see it, but it is there.

A2B4: one of the possibilities I consider is a faulty indicator module (3A0 919 235 AF), but... I have seen the light disappear when the workshop scanned and cleared the codes, which makes me think it may be OK. They were using some other software, though.

I disconnected both plugs from the indicator module and measured voltages with ignition switched on:

black plug:

1 - empty
2 - GND (brn)
3 - +12V (blk)
4 - 0V (yel-red)
5 - +9.9V (gray-gn)
6 - 0V (blu-yel) - not connected

white plug:

1 - 0V (brn-gn)
2 - +12V (blk-red)

Could someone with a similar and working setup check, what voltages are present in their car, please?

W.

Ok. When I scanned TDT Tom's B4, which has a busted clock spring, and cleared the airbag code, the light went out for just a moment, then came back on, along with the code.

-Jason

That is what I have seen when my clockspring was cracked as well. This situation is different though. Clockspring is fixed, there are no codes (unless I make them intentionally while testing), warning light stays on.

W. (Marius)

update

I spent some time testing the indicator module. As far as I can tell it is working OK. I made a little diagram along the way to help me understand its function and to ease troubleshooting. Maybe someone will find it useful:

http://pics.tdiclub.com/data/564/abs-srs-indicator.pdf

Actually, the Airbag part of the circuit is pretty simple. Both pins (AIR - 1') and (15g - 2') are inputs. Low on 1' will turn airbag indicator on, High on 2' will turn it off. 1' has higher priority and overrides 2'.

The ABS part is more interesting, as it is not only an indicator, but a signal generator as well. Once the ABS (4) goes high the module will generate a transition to low on EBV(5) after a short delay. Transition of ABS(4) signal to low will place EBV in a high state immediately.

OK, so the good news is, that the module is working, but..
the bad news is, that the module is working and that, together with other tests, points more and more into the airbag controller module direction.

Could it be, that there are two fault indicator lines in the airbag controller? One for some sort of 'hard' eror, and the other for normal operation? What voltages do you normally measure on pins 1' and 2'? Could someone check, please? Disconnecting this connector is perfectly safe btw.

W.

compu_85 said:

Ok. When I scanned TDT Tom's B4, which has a busted clock spring, and cleared the airbag code, the light went out for just a moment, then came back on, along with the code.

-Jason

Click to expand...

Actually, the reading we got when you scanned mine translated to a high resistance, but when I put an ohmmeter across the clockspring connector, it was reading a short. So I assumed there is an open in the wiring between the controller and the clockspring. (I haven't gotten back to it since then) I don't think its a broken clockspring on mine.

My airbag light has had interesting behavior for several months now. It comes on at startup and stays on for 1-2 minutes, then goes out for the duration of the trip, whether 5 minutes or 5 hours. Stop the car and restart it and the light is back on again, for 1-2 minutes each time. wierd.

tditom: there is a shunt built into one of the clockspring connectors, it short-circiuts the connector pins when unplugged.

A2B4: how is your battery and alternator? Any codes in airbag controller related to supply voltage? Intermittent? I know it is a strange question to ask a person who makes harnesses, but...

Anyone who can: please measure voltages on the white plug at airbag indicator module with respect to the ground and report.

Wypij said:

tditom: there is a shunt built into one of the clockspring connectors, it short-circiuts the connector pins when unplugged.

Click to expand...

So if I find the connector pins at the controller, is that measurement accurate?

I will attempt to measure the voltage you requested.

tditom said:

So if I find the connector pins at the controller, is that measurement accurate?

I will attempt to measure the voltage you requested.

Click to expand...

Unless I misunderstood your statement I am afraid there may be some confusion. My remark regarding clockspring was referring to your statement to Jason:

tditom said:

Actually, the reading we got when you scanned mine translated to a high resistance, but when I put an ohmmeter across the clockspring connector, it was reading a short. So I assumed there is an open in the wiring between the controller and the clockspring. (I haven't gotten back to it since then) I don't think its a broken clockspring on mine.

Click to expand...

I wanted to point out the possible reason for such reading. This shunt is a safety feature. It also helps in diagnosing clockspring gremlins. Have one end shorted, connect the multimeter set as continuity tester to the other end (in place of an airbag) and start wiggling clockspring. That is how I found a fault in mine. Have a look at the last pic here: http://pics.tdiclub.com/data/517/clockspringHOWTO.pdf


Now, back to my current problems.

The voltages I am interested in are those present at a plug at the back of the airbag warning light module in the dash. Two wires, one coloured blk/red, the other brn/grn. If you have easy access to the airbag controller then please measure there, they go to pins 20 and 7 respectively, according to my Mitchell wiring diagram.
If you find a 0V reading on brn/grn then please take an additional continuity/resistance measurement to the ground.

Wypij said:

A2B4: how is your battery and alternator? Any codes in airbag controller related to supply voltage? Intermittent? I know it is a strange question to ask a person who makes harnesses, but...

Click to expand...

All you tdi guys have the vagcoms right at hand! I don't know if there's any codes because I don't have one, haven't needed one yet. Battery is 1-year old Optima, alternator OK I guess, haven't had it checked or had any charging problems. Hey, producing wire harnesses does not an electrical expert make! I have never had to study or troubleshoot the airbag system. The only reason I knew anything about the airbag warning light was that it fell in pieces when I removed it during my heater core job.

On A3 Jetta there are two grd lugs beneath the battery tray, try to clean them. Guessing PAssat is the same. Iwould also put a heavy jumper between the two lugs.

Also never but just a clock spring, they are almost impossible to put in . You need to prewind them in the "correct direction", you have a 50-50 chance. Buy a whole steering wheel/clock spring that is pre-wound should cost 30-50$ in classifieds.

In Vag-com in the ABag controller memory there should memory location 1 and 2 ?? 0 and 1?? not sure but it lists the status if all the AB components.

This is a common problem with the lite in the cluster.

After much consternation with this issue (A-3 Air-bag light w/ no DTC) I called a local "stealership" for their input. They (O'Connor VW Augusta, Me.) wanted to replace the air-bag controller AND the instrument cluster. They were talking over $1,800 to replace these parts and then adjust the new cluster mileage for another $175.00

What I did was to use a section of 1/4" dia. heat shrink to cover the air-bag lamp. This eliminated the air-bag light!

Pulling the plug from indicator module is equally efective. Ask me how I know...

I know I'm resurrecting an old thread here, but I am dealing with a airbag issue and want some opinions.

I have been refurbishing a b4 sedan i got cheap. Windows were broken and it was soaking wet inside and smelled terrible so I pulled all the interior to clean. This included pulling the dash to deal with rats nest in the HVAC blower box. fixed lots of broken stuff along the way including the brake/airbag light which probably had the bulb cut because of a glovebox mod.

I would like to have airbags (with some assurance they will work if necessary), but don't want the light on. I know I can cut the bulb, but again want some assurance they are good if that is possible. Tried to clear the code in vag com but they come back on...both sides.

Like I said, I have a parts car. so I could swap SRS module and airbags. Module has a warning that says it can't be put into another vehicle....but it sounds like other have done that.

Thoughts?
Ideas of how to test?