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D2 - Interior Electrics Airbags, Sensors, climate modules, instrument clusters, switches etc

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  #1  
Old 7th June 2012, 10:36 AM
HPsauce HPsauce is offline
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Default Airbag warning due to seat occupancy sensor.

After all ("all" - very minor compared to some here!) my work clearing my "orange drains" the airbag warning is on.
VCDS revealed it as an "Intermittent high resistance on front passenger seat occupancy".

As I moved that seat around a lot, and to its limits, and was leaning on it from outside, I have 2 thoughts:
1. Moving it has loosened a connector or damaged a wire.
2. The intermittent/variable light/medium loads have "confused" it.
3. Something else I haven't thought of.

Anyway I cleared it with VCDS and will wait to see if it comes on again..

Any thoughts anyone, on:
1. Likely causes and are they worth investigating?
2. Will the airbag deploy if required - it's most likely to be my (not heavy) wife sitting there?
3. Is high resistance unoccupied - is it a simple open/closed switch?
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2016 Volvo V40 T5 Cross Country (4WD) with ALL the toys including adaptive cruise etc. etc. Osmium Grey with Blonde/Charcoal leather interior. Polestar performance "optimisation". (Even rarer than a D2 S8!) Oh, and a brand new engine at just under 30,000 miles on the factory one!
Finally: gone, but not forgotten.....
1998 D2 PF S8. Agate Grey/Platinum. Every option (I think) except electric rear seats, Tiptronic steering wheel, ski hatch, towbar & dimming door mirrors.
e.g. Cruise control, NavPlus/TV, Bose, GSM, Xenons, Solar roof, Parking sensors, Alcantara/leather everywhere of course. (internal dimming mirror added later)
1998 (very early) Ford Focus 1.8 Zetec; ABS/TCS, Heated screen/mirrors, Aircon. Added Auto-dim mirror, Leather seats, Trip computer, Cruise control, OEM Ford SatNav with CD changer.
And before that a lot of Rover 800s, a few oddities, a lovely Triumph Dolomite 1850HL with Overdrive and way back in my schooldays an Austin Seven aka Mini 850!
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Old 7th June 2012, 12:14 PM
PsYcHe PsYcHe is offline
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It's a common problem.. There is a thread on popping a resistor inline to solve it.
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Old 7th June 2012, 01:30 PM
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I'd be happy not to have an airbag go off in the face of a front seat passenger - if you don't sit on top of the dash there's nothing to hit in front of you anyway so likely to do more harm than good

Drivers and side bags are a different matter - wouldn't want to be without those and in many instances if the airbag warning light is on then some or all of the system may be off. Depends on the logic engineered in - I'd hazard a guess that both front bags would deploy because the system isn't sure if the seat is occupied....
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Old 7th June 2012, 01:45 PM
HPsauce HPsauce is offline
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Indeed, I believe the passenger airbag is a US-spec "full size" one designed to support a US adult NOT wearing a seat belt!
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2003 D2 FL S8. Irish Green Pearl/Beige. Solar sunroof, auto-dim mirrors, electric rear seat functions and extended leather. Ski hatch retrofit. Aftermarket reversing camera. DVB-T and XCarlink now removed as redundant.
2016 Volvo V40 T5 Cross Country (4WD) with ALL the toys including adaptive cruise etc. etc. Osmium Grey with Blonde/Charcoal leather interior. Polestar performance "optimisation". (Even rarer than a D2 S8!) Oh, and a brand new engine at just under 30,000 miles on the factory one!
Finally: gone, but not forgotten.....
1998 D2 PF S8. Agate Grey/Platinum. Every option (I think) except electric rear seats, Tiptronic steering wheel, ski hatch, towbar & dimming door mirrors.
e.g. Cruise control, NavPlus/TV, Bose, GSM, Xenons, Solar roof, Parking sensors, Alcantara/leather everywhere of course. (internal dimming mirror added later)
1998 (very early) Ford Focus 1.8 Zetec; ABS/TCS, Heated screen/mirrors, Aircon. Added Auto-dim mirror, Leather seats, Trip computer, Cruise control, OEM Ford SatNav with CD changer.
And before that a lot of Rover 800s, a few oddities, a lovely Triumph Dolomite 1850HL with Overdrive and way back in my schooldays an Austin Seven aka Mini 850!
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Old 7th June 2012, 03:44 PM
HPsauce HPsauce is offline
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Quote:
Originally Posted by PsYcHe View Post
There is a thread on popping a resistor inline to solve it.
Found that, thanks: http://forum.a8parts.co.uk/showthread.php?t=114 though it's not a "Sticky" in that section as far as I can see.... (hint)
Interestingly it says it's a variable resistance pad and part of the sensor is in the moveable thigh support, which I did in fact move at one point (SWMBO never does) as something dropped into the gap!

I'll see how it develops.

Edit: Looking on eBay there seems to be a wide selection of plug-in "dongles" to fool BMW's that the seat is occupied. But none for Audi!
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2003 D2 FL S8. Irish Green Pearl/Beige. Solar sunroof, auto-dim mirrors, electric rear seat functions and extended leather. Ski hatch retrofit. Aftermarket reversing camera. DVB-T and XCarlink now removed as redundant.
2016 Volvo V40 T5 Cross Country (4WD) with ALL the toys including adaptive cruise etc. etc. Osmium Grey with Blonde/Charcoal leather interior. Polestar performance "optimisation". (Even rarer than a D2 S8!) Oh, and a brand new engine at just under 30,000 miles on the factory one!
Finally: gone, but not forgotten.....
1998 D2 PF S8. Agate Grey/Platinum. Every option (I think) except electric rear seats, Tiptronic steering wheel, ski hatch, towbar & dimming door mirrors.
e.g. Cruise control, NavPlus/TV, Bose, GSM, Xenons, Solar roof, Parking sensors, Alcantara/leather everywhere of course. (internal dimming mirror added later)
1998 (very early) Ford Focus 1.8 Zetec; ABS/TCS, Heated screen/mirrors, Aircon. Added Auto-dim mirror, Leather seats, Trip computer, Cruise control, OEM Ford SatNav with CD changer.
And before that a lot of Rover 800s, a few oddities, a lovely Triumph Dolomite 1850HL with Overdrive and way back in my schooldays an Austin Seven aka Mini 850!

Last edited by HPsauce; 7th June 2012 at 03:55 PM.
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  #6  
Old 7th June 2012, 09:39 PM
RanjS8 RanjS8 is offline
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Default resistor for airbag

If you wire in a resistor with about 470 ohms...I think that will be enough to make the car think the seat is occupied and so if need be the airbag will deploy regardless. You may have to bypass seat belt sensor as if the car thinks someone is in the passenger seat....it then expects the seat belt to be done.

There are two green wires going to seat belt buckle and I just wired a resistor acros them two as well.
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Old 7th June 2012, 10:09 PM
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Quote:
Originally Posted by HPsauce View Post
Found that, thanks though it's not a "Sticky" in that section as far as I can see.... (hint)
It is now!
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Old 7th June 2012, 11:17 PM
HPsauce HPsauce is offline
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Quote:
Originally Posted by RanjS8 View Post
You may have to bypass seat belt sensor as if the car thinks someone is in the passenger seat....it then expects the seat belt to be done.
That was my 4th question that I didn't ask - i.e. is there a cross-check to the seatbelt being done up?
Ranj, is that the same on PF as well?
(I would expect the logic to be - EITHER of seat occupied sensor triggered OR belt done up = "live" airbag)

I do wonder if the fact that I didn't have the seatbelt done up but was pressing on the seat was adding to the "confusion".
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2003 D2 FL S8. Irish Green Pearl/Beige. Solar sunroof, auto-dim mirrors, electric rear seat functions and extended leather. Ski hatch retrofit. Aftermarket reversing camera. DVB-T and XCarlink now removed as redundant.
2016 Volvo V40 T5 Cross Country (4WD) with ALL the toys including adaptive cruise etc. etc. Osmium Grey with Blonde/Charcoal leather interior. Polestar performance "optimisation". (Even rarer than a D2 S8!) Oh, and a brand new engine at just under 30,000 miles on the factory one!
Finally: gone, but not forgotten.....
1998 D2 PF S8. Agate Grey/Platinum. Every option (I think) except electric rear seats, Tiptronic steering wheel, ski hatch, towbar & dimming door mirrors.
e.g. Cruise control, NavPlus/TV, Bose, GSM, Xenons, Solar roof, Parking sensors, Alcantara/leather everywhere of course. (internal dimming mirror added later)
1998 (very early) Ford Focus 1.8 Zetec; ABS/TCS, Heated screen/mirrors, Aircon. Added Auto-dim mirror, Leather seats, Trip computer, Cruise control, OEM Ford SatNav with CD changer.
And before that a lot of Rover 800s, a few oddities, a lovely Triumph Dolomite 1850HL with Overdrive and way back in my schooldays an Austin Seven aka Mini 850!
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Old 25th June 2012, 09:52 PM
HPsauce HPsauce is offline
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Quote:
Originally Posted by HPsauce View Post
I'll see how it develops.
Well it came back within a few hundred miles, with SWMBO (not heavy) in the passenger seat.
Cleared it today and will see how soon it returns.

As it's an "intermittent high resistance" and from what I've read it's a variable-resistance pad sensor, I presume it will need a resistor in parallel to "overcome" the problem.

Does anyone have an actual specification of the ranges that are "normal" and "acceptable" and how they are interpreted in relation to occupied/unoccupied?
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2003 D2 FL S8. Irish Green Pearl/Beige. Solar sunroof, auto-dim mirrors, electric rear seat functions and extended leather. Ski hatch retrofit. Aftermarket reversing camera. DVB-T and XCarlink now removed as redundant.
2016 Volvo V40 T5 Cross Country (4WD) with ALL the toys including adaptive cruise etc. etc. Osmium Grey with Blonde/Charcoal leather interior. Polestar performance "optimisation". (Even rarer than a D2 S8!) Oh, and a brand new engine at just under 30,000 miles on the factory one!
Finally: gone, but not forgotten.....
1998 D2 PF S8. Agate Grey/Platinum. Every option (I think) except electric rear seats, Tiptronic steering wheel, ski hatch, towbar & dimming door mirrors.
e.g. Cruise control, NavPlus/TV, Bose, GSM, Xenons, Solar roof, Parking sensors, Alcantara/leather everywhere of course. (internal dimming mirror added later)
1998 (very early) Ford Focus 1.8 Zetec; ABS/TCS, Heated screen/mirrors, Aircon. Added Auto-dim mirror, Leather seats, Trip computer, Cruise control, OEM Ford SatNav with CD changer.
And before that a lot of Rover 800s, a few oddities, a lovely Triumph Dolomite 1850HL with Overdrive and way back in my schooldays an Austin Seven aka Mini 850!
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  #10  
Old 13th July 2012, 01:27 PM
HPsauce HPsauce is offline
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Sadly this fault now seems to be permanent, it's just "High resistance" and if I clear it it returns immediately.

I guess this means it thinks the detector is broken (which it probably is) but presumably also indicates that the resistance, being variable, is treated something like:
High: broken
Medium: unoccupied
Low: occupied

Is there any documentation on what ranges these values are?

Is the only option to wire in a resistor to fool the system (and the seatbelt too) or can it be coded out in some way?

Quote:
Originally Posted by RanjS8 View Post
You may have to bypass seat belt sensor as if the car thinks someone is in the passenger seat....it then expects the seat belt to be done.
Having looked at my manual there's only an "in preparation" note against "front seat belt buckle detection" (and I've no seat belt warning light) so I'm hoping that's not on my car as it's too early.



Also does anyone know definitively if having this light on is an MOT fail?
__________________
2003 D2 FL S8. Irish Green Pearl/Beige. Solar sunroof, auto-dim mirrors, electric rear seat functions and extended leather. Ski hatch retrofit. Aftermarket reversing camera. DVB-T and XCarlink now removed as redundant.
2016 Volvo V40 T5 Cross Country (4WD) with ALL the toys including adaptive cruise etc. etc. Osmium Grey with Blonde/Charcoal leather interior. Polestar performance "optimisation". (Even rarer than a D2 S8!) Oh, and a brand new engine at just under 30,000 miles on the factory one!
Finally: gone, but not forgotten.....
1998 D2 PF S8. Agate Grey/Platinum. Every option (I think) except electric rear seats, Tiptronic steering wheel, ski hatch, towbar & dimming door mirrors.
e.g. Cruise control, NavPlus/TV, Bose, GSM, Xenons, Solar roof, Parking sensors, Alcantara/leather everywhere of course. (internal dimming mirror added later)
1998 (very early) Ford Focus 1.8 Zetec; ABS/TCS, Heated screen/mirrors, Aircon. Added Auto-dim mirror, Leather seats, Trip computer, Cruise control, OEM Ford SatNav with CD changer.
And before that a lot of Rover 800s, a few oddities, a lovely Triumph Dolomite 1850HL with Overdrive and way back in my schooldays an Austin Seven aka Mini 850!

Last edited by HPsauce; 13th July 2012 at 01:37 PM.
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