Pretensioners. ARRRGHHHHH!

Ok, I'm at my wit's end with the airbag flashing light on the dashboard. Four flash, pause, four flash etc - basically the pretensioners.

I've had this problem on and off for the last 4 years but usually some fiddling shuts them up for a bit in time for an MOT, but this year, nothing stops the nagging light.

In the last two weeks, I've done the following; Swapped the seat wiring for good ones, cleaned all connectors including the multiplug to the airbag ecu, tested the wring from the ecu to the pretensioners (checks out ok), swapped to (admittedly 6 month newer but known good pretensioners), cleaned the connectors again and cleaned the earth. STILL I have the light.

Now the MOT is due and it's an instant fail. I'd rather not bodge it through, but I've literally run out of things to check and test and still it's there, mocking me with its flashing.

Has anybody got any idea where I go from here?

Hi Lee
Won't anything show up on Forscan or you could try asking Sinisa.
Barry

The Arch Bishop said:

[post]352514[/post] Has anybody got any idea where I go from here?

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No idea, mate, don't have them on mine, so didn't learn up about them.

tuonokid said:

[post]352516[/post] Hi Lee
Won't anything show up on Forscan or you could try asking Sinisa.
Barry

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Hi Frank,

No, Forscan doesn't seem to pick up anything about the restraint system - it's not listed in there anyway. Fairly sure it's the passenger side as that was always the one that would fix it previously. I have checked and tested both sides though.

Hi Lee
It was me not Frank Just had a quick look at the Fiesta manual and on that there is a link from the 0BD to the airbag module and I reckon that's where you'll turn off the airbag warning light from so if you dig deeper or ask Sinisa there may be something. Also I noticed on that diagram that there seems to be a load sensor built into the seat so if there's only the driver the pass airbag wouldn't blow, if there is one I assume it's fed from the pre-tensioner?????
Barry

Sorry Barry - long day with a screaming pox-ridden 4 year old!

Usually, the light clears itself once it's happy, but I'll have another dig in Forscan and see if there's anything logged. There's no load sensor (just the two wires to the pretensioner and nothing else), but thanks for the suggestion!

Hope she/he gets better soon. It's something that's far too modern for me but just throwing ideas up

Guessing you matched the part number if not the age?

Hi Ian, More the year rather than the part number. I replaced my 1997.5 build ones for some 1998 ones. One digit out on the part number or something, but I swapped them back as I'd heard that the wrong ones don't work. Don't suppose you have a selection do you? :grin:

You can always do this to get through MOT: http://www.projectpuma.com/viewtopic.php?f=51&p=352235&sid=3100d5fe02cba84aa6291afc555e88b6#p352235

Also, that would, I guess, rule out the wiring and the rest of a system if the light goes out

I'm pretty keen not to bodge it, mainly because I want to know what it is that's been plaguing me! The wiring seems fine, the only thing is the pretensioner of the right code. That may not be easy though....

Have you tried the relay
I had a similar fault but with my abs , tried and checked everything, turned out to be a dodgy relay.

Get me the part number off the right ones.

Hi Ian,

Will do, but I'm off on holiday Saturday. If I get the chance I'll grab the numbers before then.

No more luck with this. I've done some further fiddling about this evening. I've removed the pins from each of the connectors and checked them - all clean. I've tried two sets of pretensioners both with the same part number, same result.

I removed the main connector from the airbag module above the glovebox and the warning light changed to a solid on state, as you'd expect. Upon reconnecting, it resumed its four flash and pause state.

The only thing really left to try is a replacement airbag module I guess? My car has now languished unusable since the MOT ran out in May and I'm losing the will to bother with it. Such a stupid problem!

I'm still loathed to trick it with the capacitor bodge, but I'm not 100% sure that that would in fact help!

It doesn't sound like it would if you've tried different pre-tensioners with the same result/

I've ordered the resistors as, for the sake of £1.30, I can at least use them as a test. If they extinguish the light, then I'll know the pretensioners are the culprit. There's always the chance that I have two sets of duds!

I've fitted the resistors - light still flashing.... Ugh.

Well at least that, in theory, rules out the pretensioners?

Maybe pointing towards the module itself?

Right, replacement module installed but still the problem persists! Unbelievable!

Next step is probably to try and eliminate the wiring. I've checked it once but it's the only thing left to recheck.... :?