Understanding the Logic behind EAS

Prerequisite :
I know for a fact that my car does not have a leak. (Removed the relay below the passenger seat, No drops even after 3 days). Still we changed the ECU (Is it name like this?) next to the Pump and now my car stop leveling for nothing at stops. Also swapped the EAS ECU for test and mine or the spare one gave the same behavior. Pump working like it should.

Now my question is simple :
After driving the car on different road conditions and mode (Normal, Highway, access) for a while (several hours). Stop the car let it rest for 2 minutes, engine on pump, run a bit and goes off. Let the car like this for 2h it will not drop, let it like this for a night the car will raise the morning (Raise quickly).

Now do all the above (drive the car... blablabla), wait for 15 minutes to 1h, start the engine, the Pump will run several time and wait until the pump no longer run (tank full?!?!). Come back the next morning 0 Drop the car do not need to raise and stand still.

What's your thoughts? Shall I go and seek help at the nearest psychiatric ward?

Sounds like a leak in your tank supply .
Read wammers how to and you will understand what's going on instead of putting your finger over the outlet exhaust fit a correct size ballon this will show small leak far easier

When you say ecu do you meen drive box it has like a silicon substance on one side ?

I think he means driver pack ?? That's next to the compressor pump.

Grit Valve said:

Sounds like a leak in your tank supply .
Read wammers how to and you will understand what's going on instead of putting your finger over the outlet exhaust fit a correct size ballon this will show small leak far easier

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I will have a check and see this "How to". But it there were a Leak there, it will show as well even if I restart the car like said here :

"Now do all the above (drive the car... blablabla), wait for 15 minutes to 1h, start the engine, the Pump will run several time and wait until the pump no longer run (tank full?!?!). Come back the next morning 0 Drop the car do not need to raise and stand still."

Grit Valve said:

I think he means driver pack ?? That's next to the compressor pump.

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Yes I meant driver pack indeed. The EAS ECU is under the passenger seat next to the EAS Relay.

Think of it like this the pump fills the tank that's its job ! If you use air from the tank ie inflate bags / rise car you use the air from the tank the pump will top it up again if in the morning/ or a prelonged wait you cannot rise car and have to wait your tank has most probably lost too much air .

I bought a kit of eBay you can check air tank or any part of the the air system for loss off air air via a inline pressure gauge very useful for finding small leaks . You say your car will not drop so this means the four bags air lines and valves are in good order they are shut of separately from the tank is an easy way to explain

Grit Valve said:

Think of it like this the pump fills the tank that's its job ! If you use air from the tank ie inflate bags / rise car you use the air from the tank the pump will top it up again if in the morning/ or a prelonged wait you cannot rise car and have to wait your tank has most probably lost too much air .

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Ok, this I get it. But when you park the car after driving it and if the pump does not run it means that the tank is full right?

A) Now let the car like this one night and the morning it will raise up (pump is working) = tank empty??

B) Drive the car for a long time. Stop it for 15m or 1h then restart it : Still no drop but the pump will run several times. = Filling up the thank??

Next morning after B), the car did not drop and stand still = Tank Full???

So my question in a way is : Can the EAS system not fully fill-up the tank when driving the car?

Grit Valve said:

I bought a kit of eBay you can check air tank or any part of the the air system for loss off air air via a inline pressure gauge very useful for finding small leaks .

Click to expand...

I will have to check this

If no leaks and compressor and valve block are working as they should, then yes, eas will fill system to correct pressure whilst driving car.

A slight drop overnight is acceptable. Up to 15 mm in 24 Hrs is acceptable. There is a window of compressor operation between around 120 and 140 PSI. If you have a slight drop in the morning because of self level (the ECU wakes up every six hours to do this, but will only adjust high corners a max of 8 mm each time) and the air pressure is in the low range of compressor operation, the act of inflating back to standard will reduce air pressure below 120 PSI and the compressor will run. If the tank is full (140 PSI) and the drop was small the action of inflating to standard will not reduce the air pressure below 120 PSI therefore the compressor will not start. All this is normal operation and nothing to be worried about.

SpacePig said:

Ok, this I get it. But when you park the car after driving it and if the pump does not run it means that the tank is full right?

A) Now let the car like this one night and the morning it will raise up (pump is working) = tank empty??

B) Drive the car for a long time. Stop it for 15m or 1h then restart it : Still no drop but the pump will run several times. = Filling up the thank??

Next morning after B), the car did not drop and stand still = Tank Full???

So my question in a way is : Can the EAS system not fully fill-up the tank when driving the car?



I will have to check this

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Here you can check any part of system depending what side you isolate for instance bag side or spin the isolator around and you can check the valve block side or tank and its pipe or leave tap open and you can check you Diaphragm ect ect


RANGE ROVER P38 EAS AIR SUSPENSION VALVE BLOCK GAUGE & TANK PRESSURE ISOLATION | eBay
You will need a short piece of 6mm air line too

wammers said:

a slight drop overnight is acceptable. Up to 15 mm in 24 hrs is acceptable. There is a window of compressor operation between around 120 and 140 psi. If you have a slight drop in the morning because of self level (the ecu wakes up every six hours to do this, but will only adjust high corners a max of 8 mm each time) and the air pressure is in the low range of compressor operation, the act of inflating back to standard will reduce air pressure below 120 psi and the compressor will run. If the tank is full (140 psi) and the drop was small the action of inflating to standard will not reduce the air pressure below 120 psi therefore the compressor will not start. All this is normal operation and nothing to be worried about.

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+1

Does all this explain why it doesn't rise after an hour or so or did I read it wrong .

Grit Valve said:

Does all this explain why it doesn't rise after an hour or so or did I read it wrong .

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You read it wrong, what he is describing is pretty normal EAS bahaviour. No drop with delay relay out = no leaks. Drop overnight with relay in = self levelling. Quite normal.

Thks everyone for you help and patience.

I must admit that I never thought that my mental health would be put under such stress when I bought this car.

SpacePig said:

Thks everyone for you help and patience.

I must admit that I never thought that my mental health would be put under such stress when I bought this car.

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I have had a few moments when I am working on the car chatting away to myself and talking to the car asking it to help me find the fault!
The p38a can test your patience and mental state but I think they are worth it.
I am even considering buying another one to tinker with over the winter

kurtjohnson10 said:

I have had a few moments when I am working on the car chatting away to myself and talking to the car asking it to help me find the fault!
The p38a can test your patience and mental state but I think they are worth it.
I am even considering buying another one to tinker with over the winter

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So I am not the only one talking to his car then... Good to know!

SpacePig said:

So I am not the only one talking to his car then... Good to know!

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I don't talk to mine, I curse at it

Datatek said:

I don't talk to mine, I curse at it

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That's maybe why you have less troubles than us then! It is very possible that your car maybe scare of U, while mine may not have any respect for me and do what the F she wants!

SpacePig said:

That's maybe why you have less troubles than us then! It is very possible that your car maybe scare of U, while mine may not have any respect for me and do what the F she wants!

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Shouting at a piece of machinery will do nothing other than upset you. Stealthy maintenance is the key to everything. Of course knowing what you are doing also helps a lot.

Just a small update on this situation for people that may have the same worries than I do.

After a week the car did not drop or needed to raise when I fired her this morning. But again I would like to stress that if I run the car and use it for a while shut her off immediately and even if the car is leveled and at correct heigh, the morning after the car will drop and raise when started.

However, is after using the car I let her "cool" or wait for 15 minutes engine off and restart her for 10 minutes (Pump will fire and stay quiet) then a week after the car will not drop and won't need to raise.

Regards