stevebrookman

stevebrookman

Well-Known Member
Morning all,
Have had an intermittent fault with my EAS for about a year. After driving for well over an hour it throws up an error. The fault was 2 "pressure signal constantly high".
Being me and not having the fault for over 6 months I didn't bother having a look until the weekend (towing the caravan next week).
Was going to change the pressure sensor on the valve block but chickened out of removing the valve block to get at it so close to the holiday.
I then cleaned all connections using contact cleaner.

It seems to throw a fault when everything is nice and warm. I was wondering if leaving off the EAS cover (if it's not raining) would result in all the electronic components running a little cooler.
Any comments would be graetly appreciated.

Cheers

Steve
 
SOunds like the Driver Pack breaking down when warm....Heat does funny things to electrickery!
 
It has been mentioned before about driver pack causing this fault. Someone has yet to explain how it does it, as it has very little to do with pressure charging circuit. It's only contribution being to open the diaphragm solenoid valve when compressor is running and closing it when it stops. Maybe as the diaphragm solenoid is held open longer and used more often than any of the others that part of the driver pack glitches and opens the valve when the compressor is not running causing the fault. But that is just my unproven theory.
 
Thanks all,
I've got a spare driver pack and will change it eventually if the problem persists.
I'll try the cover off as looking at it the EAS gubbins does nor receive any cooling air-the box doesn't have many holes.
Does the driver pack contain a pile of MOSFETs and associated bits?

Regards

Steve
 
I would imagine it does, as it is used to driver the Solenoids to open and close the Valves...so no doubt there are some heat producing components in there!
 
Update!
Did not leave the cover off but did drill quite a few 18mm holes strategically in the cover. I also cleaned all plugs using contact cleaner.
Towed the tintent for over 2.5 hours twice without a problem. Last time I towed it faulted every hour.
So fingers crossed.

Steve
 
stevebrookman said:
Update!
Did not leave the cover off but did drill quite a few 18mm holes strategically in the cover. I also cleaned all plugs using contact cleaner.
Towed the tintent for over 2.5 hours twice without a problem. Last time I towed it faulted every hour.
So fingers crossed.

Steve
Click to expand...
That's interesting, mine has faulted with "Pressure Signal Constantly High" three times in about 6 months. I assume it's the pressure switch but have not got round to changing it.
On mine it has always faulted when rising from motorway height after a rapid speed reduction. Locking the suspension either at normal height or motorway height appears to eliminate the problem.
Got a long run to the UK later this month plus some running about, I will be taking a complete spare EAS box with me.:rolleyes:
 
Can't see how the heat from the compressor has anything to do with the pressure relief vale that is on the valve block open to the elements of the engine bay. Only that if the compressor is getting hot because of a air leak of it itself is weak and is working harder and getting hotter to reach the required pressure other than the extra cooling your anticipating is allowing the compressor to run that bit longer thus reaching the required pressure.
 
Grit Valve said:
Can't see how the heat from the compressor has anything to do with the pressure relief vale that is on the valve block open to the elements of the engine bay. Only that if the compressor is getting hot because of a air leak of it itself is weak and is working harder and getting hotter to reach the required pressure other than the extra cooling your anticipating is allowing the compressor to run that bit longer thus reaching the required pressure.
Click to expand...
The driver pack, which is full of semiconductors is right next to the compressor, semiconductors are notoriously heat sensitive.
 
Yep-my suspicion is the driver pack getting too hot and triggering a fault. I've a spare driver pack but will not bother changing for now.
The EAS box itself is not very well ventilated at all-theres a slit in the side and thats mainly it. I used an auger bit to put a few holes in the top of the case allowing hopefully hot air to escape easier and a few in front near the compressor intake allowing air to flow through.Have a few computer fans lying about may plumb two of these in-one blowing and the other sucking.

Regards

Steve
 
stevebrookman said:
Yep-my suspicion is the driver pack getting too hot and triggering a fault. I've a spare driver pack but will not bother changing for now.
The EAS box itself is not very well ventilated at all-theres a slit in the side and thats mainly it. I used an auger bit to put a few holes in the top of the case allowing hopefully hot air to escape easier and a few in front near the compressor intake allowing air to flow through.Have a few computer fans lying about may plumb two of these in-one blowing and the other sucking.

Regards

Steve
Click to expand...
fair enough thought is was boxed to keep elements out off the system whatever it can suck in has a chance to corrupt the valve block especially if the intake air filter is failing .
 
Grit Valve said:
fair enough thought is was boxed to keep elements out off the system whatever it can suck in has a chance to corrupt the valve block especially if the intake air filter is failing .
Click to expand...
If there was any risk of the elements getting in, they would be sucked in through the compressor intake:eek:
The driver pack is potted so fairly moisture proof, the connectors might suffer but they corrode in any case so adding cooling holes sounds like a safe idea. Off to do mine now:)
 
Datatek said:
If there was any risk of the elements getting in, they would be sucked in through the compressor intake:eek:
The driver pack is potted so fairly moisture proof, the connectors might suffer but they corrode in any case so adding cooling holes sounds like a safe idea. Off to do mine now:)
Click to expand...

Can't see it making a lot of difference. The switching transistors are going to get fairly warm anyway. But whatever floats the boat. :D:D
 
The switching transistors are pulsed, they do not get that hot, I have a de-potted driver pack to play with.
The compressor gets quite hot, very hot if a bit tired, the top of the EAS box is sealed for the heat to collect, there are two large slots in the lower part of the box but they will not cool very well.
I've gone for a row of half inch (12.5mm to you youngsters that don't know proper measurements) along the sloping edge alonside the compressor and across the rear. It should substantially reduce the temperature inside the box.
Transistors as they age can become temperature intollerant, reducing the temperature in the box may well prolong the life of the driver pack.
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I will see what happens, if it prolongs the life of the driver pack and saves me forking out for a while I'll be happy.:)
 

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Datatek said:
The switching transistors are pulsed, they do not get that hot, I have a de-potted driver pack to play with.
The compressor gets quite hot, very hot if a bit tired, the top of the EAS box is sealed for the heat to collect, there are two large slots in the lower part of the box but they will not cool very well.
I've gone for a row of half inch (12.5mm to you youngsters that don't know proper measurements) along the sloping edge alonside the compressor and across the rear. It should substantially reduce the temperature inside the box.
Transistors as they age can become temperature intollerant, reducing the temperature in the box may well prolong the life of the driver pack.
attachment.php


attachment.php


I will see what happens, if it prolongs the life of the driver pack and saves me forking out for a while I'll be happy.:)
Click to expand...

Well Keith if all else fails, you at least have 11 1/2" plastic washers to put in the tool box. :D:D
 
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