Airbag supply voltage

[Valandil]

Hello all,

Been trying to fix the airbag light on my 2002 406 2.2 HDI coupe, pp2000 just says that the supply voltage is wrong. Any idea what could be causing it?

Most of the time it also says that the passengers airbag is neutralized as well regardless of the position of the airbag pass, though it doesn't always say this. Sometimes get right module ignition fault but I'm assuming that's just a dodgy connector.

I've taken the centre console out but can't see anything wrong apart from a couple of connectors that don't seem to do anything. Is this normal? Realised that one of them in the picture is for the cigarette lighter but don't know about the other 3.

Any help appreciated!

[steve_earwig]

Did you check the connectors on the bottom of the seats? They're the usual culprits.

Ignition module - On a diesel?

Don't know what the connectors are but if you can read the codes off the wires I can look them up

[lozz]

airbag 406.png

[Valandil]

Unfortunately I work away during the week so will have a look at the weekend. The ignition module fault is on the airbag ecu, I'm assuming it's one of the triggers for one of the airbags. I suppose if one of the connectors was dirty that may raise the voltage over the connector, I'll clean them at the weekend. Will any old switch cleaner do or should I get/do something specific? Is the ecu grounded to the chassis through the bolts that hold it in place? That could be dirty too I suppose.

Is the control unit separate from the ecu? It says the voltage to the control unit is wrong, or is that just an internal part of the ecu?

[gumby6371]

As Steve said the connector under the seat is a common fault on many makes and models of car.
Used to be on a Fiat forum a while back and some members resorted to ripping the connector out completely and fitting a household connector block.

[Valandil]

Yea I had to do it on my 106, worked a treat! I was thrown by the consistent wrong supply voltage fault, though hopefully this is a symptom of a dodgy connector or 10. I'll have a look at the weekend, hopefully I was over analyzing it!

[Valandil]

Well I cleaned all the connectors last weekend and it didn't make any difference, but when I came back to the car this weekend they worked fine! I suppose the switch cleaner did its job over the week it was sitting there.