SRS / Airbag system help.

[Daspete]

Hi all,
Just found that the previous owner had an issue with the SRS / Airbag system and rather than find a solution they just took a set of pliers to it.

So I bet you're thinking, what about the dash light and the back up?

Mr bodgit had a solution to that too. Wire a bulb from the airbag light hole to the ABS light so it goes on and off like it should for an MOT then just taped over the back up.

I want to fix the system if I can and the issues seem to be with the driver's seat. They've cut everything.
The passenger seat has an occupancy sensor bypass on which is not a concern for the moment.

On a face lift 2001 Z3 what should be there?
The only thing left is the cable to the pretensioner. I've found the remains of a wire from the buckle but have no Idea where it goes.

Any help would be greatly appreciated or does anyone have a complete seat/seats from a late model in black in good condition I could buy?

Thanks in advance

 

[gookah]

Mr bodgit had a solution to that too. Wire a bulb from the airbag light hole to the ABS light so it goes on and off like it should for an MOT then just taped over the back up.

With that level of ingenuity, you would expect that person to have had the wherewithal to find the original fault.

 

[Daspete]

With that level of ingenuity, you would expect that person to have had the wherewithal to find the original fault.

You would think so. The seat is just pure butchery might be easier to just get another seat.

 

[mrscalex]

The SRS system checks for the presence and correct function of the seatbelt pre-tensioners. As well as the passenger occupancy mat. So it's going to have a freak out with a cut harness. The passenger occupancy bypass is an okay hack to my thinking as the mat is troublesome, requires the seat to be dismantled to fix and all it really does is tell the car if someone is sat in the seat and if they are to fire the passenger airbag. Primarily to stop airbags going off into baby seats.

Why a previous owner thought it was sensible to drive without the pre-tensioners is any one's guess. They fire a small explosive charge on crash detection and lock the seat belt quicker than manual tension can happen.

How do you fix it? I would suggest you're going to need full sections of the loom cut from a similar scrap car. Then just graft it on, preferably soldering and using heat shrink. I would also suggest you find a willing owner near you so you can examine a complete installation. Or maybe be there/take photos when the donor sections are cut.

 

[mrscalex]

Ah hang on a moment. I'm assuming you meant the chassis loom was cut. You mean the seat loom? Replacement seats are going to be your easiest bet here. As long as they aren't Sport seats you could pick up a pair for £200-£250. And get a few quid back selling the motors from yours.

 

[IainP]

I have a set of coupe seats sitting beside the Z, I'll have a look tonight and see if it's the same connector for the pretensioner as the Z.

 

[Daspete]

Ah hang on a moment. I'm assuming you meant the chassis loom was cut. You mean the seat loom? Replacement seats are going to be your easiest bet here. As long as they aren't Sport seats you could pick up a pair for £200-£250. And get a few quid back selling the motors from yours.

Yes that's it, it's the seat loom. The chassis is a bit damaged but could be salvaged with some bullet connectors as the wires are all still there. The seat loom..... I have no idea, no much left of it

 

[Daspete]

This is what is left of the chassis loom. Looks like there was a damp issue which caused corrosion and then a faulty connection. Why on earth they didn't just clean the connector or replace the connector with even just bullet connectors i beyond me.
Destroying some expensive components and hacking the binacle apart is far easier of course. Having the safety systems disabled is a much better idea.

I'll get a pic of my seat loom later.

 

[mrscalex]

Can't see your attachment. However if the seats are coming from a breaker I would ask the seller to let you have the chassis side loom in case.

 

[Daspete]

I heard some where the air bag control module might be scrap now because it hasn't been reset for so long. Is this true?

 

[mrscalex]

I heard some where the air bag control module might be scrap now because it hasn't been reset for so long. Is this true?

A reset would only be necessary if the car was in an accident and the airbags had been deployed. That's then a job for a specialist.

What it may and probably will need is the associated error codes to be reset once the underlying faults are fixed. That's easy though with a basic tool.

 

[IainP]

Possibly. My problem, car was run for over 2 years with airbag on, module went today to see if it can be reset.
Seats I have are out of e46, my connectors are different, only 2 wires in/out, not much use to you.

 

[Daspete]

I think they're the only 2 wires that haven't been chopped.
Is it only the passenger side that has an occupancy sensor?

 

[mrscalex]

I think they're the only 2 wires that haven't been chopped.
Is it only the passenger side that has an occupancy sensor?

Yes only passenger side.

 

[Daspete]

So if I have the wires to the pretensioner that just leaves the seat belt switch wire missing that goes in to the buckle then?
That is definitely chopped off, there is only a stump left.
Does the passenger side have a seat belt switch as well or just the driver's?

 

[Daspete]

This is what I have on the driver's side.

 

[gookah]

where the arrow points to, is it the actual wire rope that pulls the seatbelt tight when the tensioner activates?
It may have been fired, and then the rope cut to release the seat belt socket to its original position?

may be totally wrong, if it is a seat belt fastened detector, but I didnt think the Z3 had them?

 

[Daspete]

where the arrow points to, is it the actual wire rope that pulls the seatbelt tight when the tensioner activates?
It may have been fired, and then the rope cut to release the seat belt socket to its original position?

may be totally wrong, if it is a seat belt fastened detector, but I didnt think the Z3 had them?

The wire rope is still in there. Inside where the arrow is pointing are 4 different colour wires.

 

[gookah]

OK I was wrong then, maybe the last models had detection.

 

[Daspete]

This is what the part number comes up as.