brianp38dse
Well-Known Member
Have you cleaned and checked all the connector pins in the eas box and ecu , you can lock it at motorway height, I run mine in that all the time
The connector blocks in the EAS box in the engine bay, the ones to the driver pack but also to the compressor. What are they like? If you can get something in there to crimp them so they grip tightly when plugged together then that might help. Something to file the connectors too. I am sure @pwood999 has something to do this. A mouse file or something?
ovalandrover
Well-Known Member
I had a problem with burnt terminals on the compressor connection in the EAS box had to cut them out and use spade terminals.
http://www.rswsolutions.com/index.php/p38a-eas-system/180-p38a-eas-electronic-control-unit
is there anything here that could help?
or else do you have anybody who would let you borrow an ecu to rule it out?
do you have any hair left after pulling at it??
is there anything here that could help?
or else do you have anybody who would let you borrow an ecu to rule it out?
do you have any hair left after pulling at it??
ECU could indeed be your problem. But before you invest in a new one check the connections to the valve block pressure switch are sound. Clean and tighten them. Compressor circuit is completely separate from all other circuits. It is self contained.
tomcat59alan
Well-Known Member
Sorry for being quiet ,I have a spare driver pack in the garage you could have borrowed, you said you had to bridge the yellow relay to get the compressor to run. How about a faulty fuse box,a common fault.
A working driver pack has nothing at all to do with compressor circuit. Compressor circuit is self contained. When pressure switch shows low pressure, ECU pulls relay to start compressor and this also powers diaphragm solenoid to apply pressure to bottom of diaphragm to seal it.. When pressure switch shows high pressure ECU drops relay to switch compressor off, power is removed from diaphragm solenoid, air from below diaphragm holding it closed is vented into the loom via 4 mm pipe and high pressure air is vented past diaphragm to atmosphere, as same gallery is used for filling tank and venting from bags. That is why if when compressor is running and a lower height is selected. The compressor stops and high pressure air is vented before any air can be vented from bags to lower car. Although it has been known for a duff driver pack to upset the ECU and cause all manner of problems because of electrical feed back.
stemac33
Well-Known Member
I was having probe with our easy about 6 months ago kept throwing up faults would work OK for about a week or so and after changing all the sensors pressure switch and other bits and bobs I got hold of a second hand driver pack and haven't had any problems since. Try a different driver pack as I've heard that they can become damaged internally from the heat. Hope you get sorted soon as air is much better than springs.
Air pressure constantly high fault can certainly be caused by a duff driver pack which effects compressor operation. But as said earlier the driver pack has nothing at all to do with the compressor circuit. No part of the compressor circuit runs through or is controlled by the driver pack. Normally the driver pack is a slave of the ECU, it pulse opens and closes the corner, inlet and exhaust valves as required subject to signals from the ECU, using voltages the ECU itself cannot handle. It can however fail and electrical feedback can effect the ECU and cause it to malfunction.
PPP38vouge
Active Member
Hi,
I have a spare ECU if you would like to try it, also a driver pack if your interested. PM your address and I will post them over to you.
Hope this helps.
Paul.
I have a spare ECU if you would like to try it, also a driver pack if your interested. PM your address and I will post them over to you.
Hope this helps.
Paul.
tomcat59alan
Well-Known Member
Which relay was he bridging? Shouldn't have come in halfway through the post I just saw somebody taking my name in vain and calling me plasticA working driver pack has nothing at all to do with compressor circuit. Compressor circuit is self contained. When pressure switch shows low pressure, ECU pulls relay to start compressor and this also powers diaphragm solenoid to apply pressure to bottom of diaphragm to seal it.. When pressure switch shows high pressure ECU drops relay to switch compressor off, power is removed from diaphragm solenoid, air from below diaphragm holding it closed is vented into the loom via 4 mm pipe and high pressure air is vented past diaphragm to atmosphere, as same gallery is used for filling tank and venting from bags. That is why if when compressor is running and a lower height is selected. The compressor stops and high pressure air is vented before any air can be vented from bags to lower car. Although it has been known for a duff driver pack to upset the ECU and cause all manner of problems because of electrical feed back.
. Been knackered since the weekend .
Which relay was he bridging? Shouldn't have come in halfway through the post I just saw somebody taking my name in vain and calling me plastic
Relay 20 i would think to bring on the compressor. Nothing plastic about you more like Teflon.
Correct. If there are no faults showing like pressure constantly high, which is usually down to duff driver pack interfering with ECU. Then it can only be down to pressure switch sending wrong data or the connections to it not making properly. Or of course the thermal switch being intermittent for same reasons. Maybe checking the ground point on the N/S inner wing would be an idea. Duff ECUs are rare but of course all is possible.
Think his compressor is new? Unless he cooked it feeding a leak?
Capripaul
Member
Thanks for al the reply's, I'm slowly working through all the advice starting with ensuring that all connections are clean and tight fitting (Rain is stopping play at the moment as well as having to go to work), Ill try and answer some of the questions below.
Wammers ; I didn't know about the earth point I'll check this out, Thanks
The other thing I cant get my head round with the compressor is that I can make it run with the EAS unlock software, I'm assuming this still powers the same way through the relay etc. so at least some of the compressor circuit must be functioning or does it switch it a through a different route with the software.
Yes new compressor which still works fine when it runs and thankfully no leaks at the minute.
I fitted a new pressure switch (seemed like a good idea at the time) this seems to test out fine switching as required with my meter across it.
Wammers ; I didn't know about the earth point I'll check this out, Thanks
The other thing I cant get my head round with the compressor is that I can make it run with the EAS unlock software, I'm assuming this still powers the same way through the relay etc. so at least some of the compressor circuit must be functioning or does it switch it a through a different route with the software.
EAS Software will ask the EAS ECU to switch the relay to run the pump....just the same way as the ECU would command the relay to switch in normal operation....
If you can get the pump to run correctly by commanding it to via the software, I would say the ECU is at fault and is getting spurious electrical spikes from somewhere (driver pack as mentioned above) and it is modulating the compressor to run intermittently and in rapid succession.
If you can get the pump to run correctly by commanding it to via the software, I would say the ECU is at fault and is getting spurious electrical spikes from somewhere (driver pack as mentioned above) and it is modulating the compressor to run intermittently and in rapid succession.
