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Discussion Starter #1
Guys,

Appreciate any help here.

I recently had the yellow airbag driver restraint system error light come on. This did not seem to be linked to moving the seat but it has been very cold recently.

Searching forums points to broken wires or plugs under the seat as a likely cause and I have had a brief check for this. I understand there is no occupancy mat as by default a car must usually have a driver for it to be moving.

I have not yet asked my friendly BMW specialist for a diagnostic check, I would guess they will confirm the I-Drive error message.

Everything looks ok and after disconnecting the battery and reseating all plugs and wiggling the loom and cables the error remains. I want to establish if this is actually the actuator faulty, a wiring issue or perhaps a stored error due to a brief disruption caused by a broken wire or similar. Trouble is, using a meter to check continuity is not a good idea as it might trigger the pyrotechnics.

My questions are:

1. Has anybody tried connecting the loom for the drivers side to the passenger actuator to establish if the fault disappears?
2. Anybody know whether it is possible to 'test' for electrical continuity in the device or the loom without the tensioner detonating? Anybody know of a pretensioner 'simulator' circuit (like for the passenger occupancy mat) that could be used to test the loom without the pretensioner connected?
3. Does the small black plug taking the 2 wires of the loom into the tensioner on the top of the tensioner 'unplug' or is it permanently attached? (I do not want to break it but it does feel quite wobbly)
4. BMMINI parts seem to supply a new pretensioner unit for around £50 (unless I have misread their parts prices) - have any others experienced them going faulty rather than just wiring?

Appreciate any pointers from others that I am sure have experienced the same issues!

Many thanks

Euan
 

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Ive not seen a 2005 E61 M5 before. Cant be an M5, they only appeared post 2007. Either way, the fault you have mentioned is new to me.
 

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Discussion Starter #4
You are correct - this one is not my V10, it is my daily driver but the restraints look identical to my E60 M5 so I thought it worth asking if any others had seen the same fault.

Will try a system diagnostic reset and see how that goes...

Euan
 

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Hi Euan,

did you manage to get this sorted? Give me some info pal as I've just picked my E60 M5 up and i have the same fault. Ive had the diagnostic machine reset but appeared again after about an hour!

Ste:confused2
 

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Discussion Starter #6
I disconnected the battery, opened all of the connectors under the seat and checked the wiring. In the end I found no faults and after reassembly the second attempt at a reset worked.

I put it down to having lowered and pushed back the seat as far as it would go while cleaning. I think there must be a questionable connection somewhere in the loom and the fault showed up.

So far, the fault has not returned.

If you can get a 'real' version of DIS there is a technical module to work through that will perform the fault finding and suggest what is wrong. Apart from the wiring it could be the belt pre-tensioner module at fault.

I would try a thorough wiring check first as the tensioners are expensive!

Good luck!

Euan
 

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Thanks Euan, i will let the specialist thats gonna look at it know what you have said here! I have to wait for a phone call to get it booked in as he's not in as yet so will post on here as soon as it's been look at. :M5thumbs:
 

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Had car in today and the specialist has replaced a connecter in line with the positive battery lead. Seams to have cured it! (lets hope so anyway).

Cheers
 

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Discussion Starter #9
Sounds like the 'Intelligent Battery Sensor' area which includes a charge to cut the battery line in case of accident and is part of the airbag/safety system. Glad things are fixed... hope it stays that way!

Euan
 
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