Felicia Airbag Light - not the usual problem.......

[CrazyRed]

Here's one for you electrical experts to get your teeth into, as it's flummoxing me!

 

Pre-FL MK1 Felicia Estate, 1997. A (knowledgable) friend and I were doing some running repairs and upgrades to the car, and I mentioned that I'd really like a rev-counter - and the (MK2) donor car had one!

 

Cut a long story short, we ended up keeping my speedo, temperature gauge and fuel gauge and otherwise transplanting the MK2 dash into my MK1. Mine is a 1.3LXi, the donor was a 1.3GLi.

 

However, the airbag light is permanently illuminated with the ignition on and will not extinguish. No faults logged in the airbag ECU and the car's been scanned with VAGCOM a number of times. Unplug the airbag ECU and this infernal light still shines brightly!

 

All other warning/information lights and gauges work absolutely perfectly.

 

Is there a difference between a pre- and post-facelift dash panel, or is it possible that my donor car had a faulty dash panel, causing this light to stay permanently illuminated?

 

I'm happy that the airbag system is operational (based on the VAGCOM scan) but, of course, the light being illuminated is an MOT fail in the UK these days so I'd like to correct this ASAP.

 

Any advice, please?

 

[RicardoM]

Did both cars have airbags from factory?

[CrazyRed]

Yes. Mine had a single airbag (drivers) and the donor car had two (driver and passenger).

 

My airbag ECU was the one used - the only change to mine was the physical dash panel and circuit board.

[RicardoM]

I want you to check the female connector (black) going to the back of the PCB (see photo).

Tell me if there is present a black/green wire at pin 7 (arrow). If yes, measure if it is connected to ground.

 

 

One other thing. What is the status of the airbag control unit and airbags from the donor car?

Edited 8 February, 2016 by RicardoM

[felicia16v]

Was the donor car the same engine? I seem to remember this happening if you fitted a 1.6 dash to a 1.3 or diesel. Your could just swap the clock/rev counter over in the original dash.

[RicardoM]

Your could just swap the clock/rev counter over in the original dash.

No, you can't. 1.3LXi has an analogue clock and different PCB. A tachometer needs also a custom IC and the digital clock another custom IC.

Edited 8 February, 2016 by RicardoM

[felicia16v]

Ah ok maybe it was the older favorit clocks you could swap around then

[felicia16v]

Ah ok maybe it was the older favorit clocks you could swap around then

[RicardoM]

CrazyRed

Just to be sure, a few things to do:

• did you try erasing the errors memory? Even if there are no errors. Erase, read, end output.
• is the coding status of airbag control unit (ACU) OK? I know it is the original one, but give it a tr
• what brand / type of ACU is installed in your car? Also in the donor car.

Now, getting back to the black connector I mentioned previously. If the wire at pin 7 exists and it is connected to ground, disconnect it from ground. The idea is to check donor car wiring of pin 7 and match it on your car in terms of connection to ground.

[uma1998]

Your have to pop down mine crazy red and I will fix it

..

[RicardoM]

Your have to pop down mine crazy red and I will fix it

:no:     

Edited 10 February, 2016 by RicardoM

[CrazyRed]

Thanks, everyone, for your advice.

 

Ricardo, I haven't yet checked the item you suggested because the car is my DD and I won't get time to strip out the dash again until probably next weekend. I will certainly check the plug you mention then and report back. The airbag control unit on mine appeared to be OK when the coding was checked (that was a thought that had come up in my mind, too). I've got to reinstall the scanning software on my laptop over this weekend, anyway (I think I cocked up the last install), so will re-scan and clear the errors again over this weekend - that said, this was something we both did on the day as well, when the light refused to go out. I don't know the brand of the airbag or the ACU - we did fit a later airbag to mine, but I would have thought this would log a fault if the airbag was not the one expected. Every other part of the dash, every instrument, every light bulb, every other warning light works absolutely perfectly and exactly as expected which is why this one light refusing to play ball is quite infuriating. My gut feel suggests this could be a faulty dash panel itself because the light remained illuminated even with the ACU unplugged. However, I'd like to be absolutely certain before I condemn a part that contains something I wanted as an upgrade - the rev-counter.

 

Uma - I know I need to come up to you to sort this. I didn't want to waste your time if this turns out to be something that I can do myself and resolve. I also recognise that the rare weekends off call that you get (I used to be on call most weekends myself, so understand the need to take a break) are valuable family time. This does limit our opportunities to meet somewhat!

[RicardoM]

Every other part of the dash, every instrument, every light bulb, every other warning light works absolutely perfectly and exactly as expected which is why this one light refusing to play ball is quite infuriating. My gut feel suggests this could be a faulty dash panel itself because the light remained illuminated even with the ACU unplugged.

The main difference in wiring between MK1 and MK2 is that pin 7 is connected or not to ground. The photo below should help you look for differences between old board and new board. If they are identical on the tracks I've highlighted, the only thing you have to look is how pin 7 of black connector (T10d) gets wired.

 

[RicardoM]

[CrazyRed]

Well, for anyone still following this thread, the problem is now resolved.

 

With thanks to not only Ricardo for putting us on the right track, but uma1998 too for actually fixing it.

 

Ricardo, when we got the dash out again, my plug was exactly as per your original picture - with pin 7 actually devoid of any cable, or pin. We discovered (by using a temporary jumper cable) that earthing this pin 7 made the airbag light behave exactly as expected, so uma found a length of wire of the correct colour from an old loom, already attached to a pin, and installed and earthed it.

 

At long last, the airbag light does exactly what it is supposed to do!

 

Thanks to all for assistance and input.

[RicardoM]

Thanks for the feedback. It is nice to hear my effort to help paid off.

[uma1998]

It worked a treat and I remember it for another time need some air con wireing diagrams is there any off them about