Airbag light in the 406 - Desperate for a solution

Talk about the 406's electrical system, what wires do what, how to add extra functionality, etc.

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BigMak
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Airbag light in the 406 - Desperate for a solution

Post by BigMak »

Hi dear friends!

I have a 406 1.9 TD 1999 with the airbag light is on and I'm having trouble solving the problem.

I went through the contacts under the front seats and steering helix with welding.

What I know for sure - that the helix wheel and airbag dismantled another vehicle that I have are perfectly good!

What else could be the problem?
What else can I check?

Ariel.
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steve_earwig
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Re: Airbag light in the 406 - Desperate for a solution

Post by steve_earwig »

On my D8 the airbag light was flashing, it turned out the ecu had died. I think if the light is on constantly it means the fault is elsewhere, can you get any diagnostics done?
Unskilled meddling sin©e 2007

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Doggy
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Re: Airbag light in the 406 - Desperate for a solution

Post by Doggy »

The one on my bro's 1.9 was the ecu too.
The connector mysteriously worked itself loose shortly afterwards, :? but I guess you won't get one through an MOT like that nowadays.
I expect you could acquire one at a scrappy easily enough.
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Re: Airbag light in the 406 - Desperate for a solution

Post by scoopeydiesel »

I had the same problem on my D8 and it was the ecu under the handbrake. The light came on again after about a month, this time the connection to the ecu had come loose. Have a look at the connection first as it may have come loose. There is a procedure to be followed when working with the airbag as it could explode.
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Re: Airbag light in the 406 - Desperate for a solution

Post by gumby6371 »

If you can get it on Planet it should identify the problem area, if you can't I'd check/swap the ecu as previously suggested, no BSI on a D8 so you can just pull the battery with out the electrice going crazy.

Next step would be swapping the pre-tensioners, if you have another pug with the same connectors try swapping the seats temporarily.

Next CAREFULLY swap the airbags themselves

If you really can't pin it down there is always the option to wire the warning light to the glow plugs :cheesy:
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jonsowman
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Re: Airbag light in the 406 - Desperate for a solution

Post by jonsowman »

Where are you based? Perhaps someone local to you can scan the car with PP2000 for you.
gumby6371 wrote:If you really can't pin it down there is always the option to wire the warning light to the glow plugs :cheesy:
Cheeky! :shock:
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Re: Airbag light in the 406 - Desperate for a solution

Post by BigMak »

Hey!

After your good advice, I want to tell what I did this weekend:

I got another fix Airbag ECU unit from another vehicle that i had (406 1.8 D8).
I connected it to the car, and the lamp still blinks ...

Those ECU that I suspected it is broken, I put on the second car and ... Is normal, the light is not flashing at all!

Now what?

I want to note:
When I replaced the helix, the air bag light was fine for half an hour, then back to flash and then remain lit permanently.

Ariel.
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Doggy
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Re: Airbag light in the 406 - Desperate for a solution

Post by Doggy »

BigMak wrote:I want to note:
When I replaced the helix, the air bag light was fine for half an hour, then back to flash and then remain lit permanently.

Ariel.
Not sure what you mean by, 'helix', but if you're saying it was OK for a short period after changing something, then it's very likely to be the connector(s) you disturbed making poor contact. Try disconnecting / re-connecting several times. If that works, even briefly, you have located the problem.

....then find another way of making the connection, (solder the wires together, or twist them and clamp in a connector block), for example.
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2003 HDi 2.2 6-speed Exec Estate (2012-19) (also a gem)
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2008 BMW E91 330i touring (great fun - murdered by a reversing SUV)
2007 BMW E91 325i touring (slower smoother quieter)
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