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

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  #11  
Old 27th July 2020, 06:59 AM
C4R 100N's Avatar
C4R 100N C4R 100N is offline
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***UPDATE***

1. FPR - have not checked that


Thank you Sean!
2. Plenum area where ECU housing, A/C bits other? stuff is located was full of water. I pumped it out with an oil sucking pump thing that i use to add transmission fluid to my A6.(any tips on how to clean that now as I don't want it rusting - oven at very low temp?) Took 12 pumps to get most of the water out. Looks like the rite of passage that is 'Botang's hole' is in my future.


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Originally Posted by The_Laird View Post
...Worth a look.
3. Removed the ECU housing cover to check for moisture / water ingress. It seemed completely dry to me.

4. Checked for moisture among the relays in the passenger footwell area. None found. Checked each relay for operation by cycling ignition switch and feeling each relay for a 'click'. Each relay responded with a click.

5. As the car was parked on a slight hill last night, facing up the hill, I spent 10 minutes or so soaking up the water in the rear passenger's floor carpet with a chamois - both sides.

6. Tried to get the S8 mobile - car starts fine but misfires badly and will stall if I step on the pedal with anything other than a feather touch. If I do use a light touch then I am able to get the car to rev at approx. 3600rpm according to the tachometer.

Could not get the car to move without stalling. CAT light is on, ASR light comes on and off. Petrol gauge showing somewhere over half full.


Thank you Michaela for nudging me in this direction.
7. Went and got 10 litres of petrol and added to tank. Car behaves a little better and was able to gingerly drive it back to my place. As MJ opined - suggests fuel starvation?? (i did not replace any of the o-rings when I replaced the fuel pump)

Still to do because it continues to rain heavily here: go to petrol station and fill car up, noting how much fuel it will accept. I am now wondering if there is a problem with the fuel sender or gauge.
Back story: on Thursday night, after going to a shop about 1km form here, I started the car up and was greeted with the low fuel beep and light. Thought no more of it, although was a bit surprised as I did not think that it was that low in fuel. Next day the petrol level seemed fine.

I can hook up my cheap diagnostic cable now as I am near power. Is there anything that I should be looking for, or any particular channel that I should scan, or any tests that I can perform in order to troubleshoot/diagnose a potential fuel issue?

Sorry for the long read to those that made it this far!
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Last edited by C4R 100N; 27th July 2020 at 07:08 AM. Reason: Acknowledging contributors
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  #12  
Old 27th July 2020, 09:07 AM
MikkiJayne MikkiJayne is offline
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Thoughts in purple

Quote:
Originally Posted by C4R 100N View Post
***UPDATE***

1. FPR - have not checked that
That was a long shot and based on latest info probably irrelevant

Thank you Sean!
2. Plenum area where ECU housing, A/C bits other? stuff is located was full of water. I pumped it out with an oil sucking pump thing that i use to add transmission fluid to my A6.(any tips on how to clean that now as I don't want it rusting - oven at very low temp?) Took 12 pumps to get most of the water out. Looks like the rite of passage that is 'Botang's hole' is in my future.

This is the plenum drains - the main culprit being under the AC housing, plus one in either wheel well.

3. Removed the ECU housing cover to check for moisture / water ingress. It seemed completely dry to me.



4. Checked for moisture among the relays in the passenger footwell area. None found. Checked each relay for operation by cycling ignition switch and feeling each relay for a 'click'. Each relay responded with a click.

Not Botang's then, although its still worth doing

5. As the car was parked on a slight hill last night, facing up the hill, I spent 10 minutes or so soaking up the water in the rear passenger's floor carpet with a chamois - both sides.

Always park down hill if poss - it helps reduce water ingress if there is any

6. Tried to get the S8 mobile - car starts fine but misfires badly and will stall if I step on the pedal with anything other than a feather touch. If I do use a light touch then I am able to get the car to rev at approx. 3600rpm according to the tachometer.

Could not get the car to move without stalling. CAT light is on, ASR light comes on and off. Petrol gauge showing somewhere over half full.

Still sounds like lack of fuel

Thank you Michaela for nudging me in this direction.
7. Went and got 10 litres of petrol and added to tank. Car behaves a little better and was able to gingerly drive it back to my place. As MJ opined - suggests fuel starvation?? (i did not replace any of the o-rings when I replaced the fuel pump)

I wonder if you have the same problem I have with Big Red in that 99% of the time everything is fine, but now and then it has trouble going to low fuel level. I'm not entirely sure what this is tbh - whether its a pump problem or a sender problem.

Still to do because it continues to rain heavily here: go to petrol station and fill car up, noting how much fuel it will accept. I am now wondering if there is a problem with the fuel sender or gauge.
Back story: on Thursday night, after going to a shop about 1km form here, I started the car up and was greeted with the low fuel beep and light. Thought no more of it, although was a bit surprised as I did not think that it was that low in fuel. Next day the petrol level seemed fine.

I can hook up my cheap diagnostic cable now as I am near power. Is there anything that I should be looking for, or any particular channel that I should scan, or any tests that I can perform in order to troubleshoot/diagnose a potential fuel issue?

Sorry for the long read to those that made it this far!
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  #13  
Old 27th July 2020, 09:15 AM
HPsauce HPsauce is offline
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Quote:
Originally Posted by C4R 100N View Post
Plenum area where ECU housing, A/C bits other? stuff is located was full of water. I pumped it out
Progress at least.
If the plenum is full of water (been there, got the t-shirt) it's the plenum drains (big drains) that are the main culprit, they will be blocked with debris.

Botang's hole is a secondary minor irrelevance in that case, it allows water to flow through into the footwell in the cabin, potentially wetting the relay panel.
In a RHD car it's difficult to get at because of the ECU box.

I clear my big drains (regularly) with hot water, detergent and lots of sucking and blowing through a flexible pipe pushed as far down into them under the HVAC intakes as I can get. After syphoning out as much as I can first of course.

Another important point is that dirty water from the plenum overflows and somehow finds its way into the cabin via the HVAC system and into the HVAC condenser tray.
That then causes the condenser drains (which are much smaller) to get blocked; they're designed on the assumption that only clean water from the air conditioning system dehumidifier ever gets to them - how wrong that is!
So you'll need to get the transmission tunnel side panels off and unblock the famous "orange drains" as well.
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2003 D2 FL S8. Irish Green Pearl/Beige. Solar sunroof, auto-dim mirrors, electric rear seat functions, ski hatch retrofit; extended leather. Aftermarket DVB-T, reversing camera and full XCarlink (Bluetooth etc.).
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". (A much rarer model than a D2 S8 by the way!) 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. AgateGrey/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, Auto-dim mirror, Leather, 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; 27th July 2020 at 09:22 AM.
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  #14  
Old 27th July 2020, 01:11 PM
Regulus Regulus is offline
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Two years ago my car wouldn't start after driving 300m or so. Audi first figured the fuel pump was no longer working. Turned out it was only a general purpose relay that was faulty, 4H0 951 253 A.
Could this cause your symptoms?
The relay is very inexpensive, I paid SEK 205 for the part.



On LHD cars, the relay box sits on the drivers side, opposite the ECU on the passenger side
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Last edited by Regulus; 27th July 2020 at 01:14 PM.
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  #15  
Old 28th July 2020, 01:37 AM
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27litres 27litres is offline
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Hi Paul,

You'd better do the whole drains scenario mate.
Just after I bought mine, had a big downpour while parked at work. Got in after work, drove the car out of the compound gate and stopped to close and lock it and wore a bucket of water down the back of my head!
Carefully drive home (not far and quiet roads fortunately) and heard gurgling from the HVAC system before it spat a bit of water at me!

I had blocked rear sunroof drains (which filled the roof liner and drowned the battery box, entertainment cubby, and spare wheel well) and blocked HVAC drains (which filled the HVAC core and drowned the rear mats and flooded the under floor vents)!
No water in plenum amazingly.
Cleared, cleaned, and blew out the drains, mopped up the mess (No lasting effects from the Bose amp or parking sensor ECU being drowned).
I installed a tow bar not long after, which required bumper removal, so cut the silly dust nipples off the rear sunroof drains.
You can do the same to the ones in the front wheel wells.

Assuming no codes that can't be explained by fuel starvation, MJ's low fuel scenario sounds pretty plausible to me, as does Johanne's, if filling your tank doesn't solve your fuel issue.
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2002 Audi S8 - Project
Replacement head coming arrived thanks to MJ
Silver with Black interior. All features as the '01, with the 'S' mode auto shifter. Dodgey rear tint (need to find a way to get rid of that).
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2009 Volvo XC90 V8 R Design
- has a louder more obnoxious exhaust than the S8, sounds great! Love this thing - Q7 was double the price, and certainly not double the car!

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