Always had occasional issues since converting back from springs about 3 years ago. Usual slow to go up, that's all. No dropping corners or such like. Could go many weeks without a problem. Not now...

Faults listed were front L/H & R/H height sensors plus an unknown, (think it was called something else).

I replaced the height sensors but this didn't improve matters. If I leave the car and it settles a bit, occasionally it will take ages to go to correct height, sometimes a few hundred yards, sometimes 10 miles!

If I clear all faults, all is good and ride height is achieved.

Decided to check pump the other day as the periods of, "playing up" are becoming more frequent. Start car, light flashes to achieve correct height but pump remains silent! Now when I clear unknown fault, pump fires up and problem solved.

I will add that I renewed all O rings and seals to valve block and pump when I brought the car back to EAS.

It seems to me that sometimes the pump isn't asked to switch on, any ideas.

Strangely today after the car had been sitting on level ground unused for two weeks, I started up and within about a minute it was at ride height. Later today, I reversed to hitch a trailer on a slope. Switched of ignition, got out the car and a clicking noise was heard, (valve block opening?) and the car settled down a few inches for no apparent reason!!! So annoying

I really need to solve this as it is ripping the joy out of driving this car...Help please.

Last things first. The clicking is normal as it will settle 3 corners to match the lowest when you switch off so it is sitting level (or at least all corners will be at the same height).

Pump will be inhibited if there is a soft fault which would explain why it started when you cleared the fault. The fact that it takes ages to rise suggests either the pump isn't supplying enough pressure or you have a leak at the reservoir or in the pipework to it so it loses all pressure meaning the pump has to fill it first before the car will rise.

Thanks for responding so quickly, you are a marvel!

I will keep an eye on it when it doesn't rise immediately but I believe the pump isn't activated as it will go days/weeks without misbehaving!

Naturally those periods are becoming more frequent hence this thread. Will be more aware when it won't level and check if pump is running.

If it isn't, any forward thinking ideas? I can switch the pump on manually using the Nanocom.

If you've got a Nano you can check to see if the pump is running. You can also see the state of the pressure switch and thermal switch in the pump. Looking at those might give you a clue as to what is going on.

Thanks, will check tomorrow.

Don't forget the relay in the under bonnet fusebox.
I had been chasing my tail on an intermittent compressor issue for too long. Turns out the relay was acting like a thermal circuit breaker. New relay, no issues!

That sounds like a cheap thing to replace as a try... Thanks.

Car has been OK for a couple of days. Started the car yesterday and the normal ride height light was doing the flashing thing. Car was lower than should be after being parked on a level surface. Pump silent, hmm. Located the relay and swapped it for another from the fuse box. No change.

Broke out the Nanocom. Faults that came up, (that never have before...)

Front right height sensor out of range
" " " " " " "
Rear left. " " " " "
" right. " " " " "

Plus the usual,"invalid fault code".

I cleared these, no pump starting

Went to "utilities" and started the pump manually.

Pump ran and after a while the rear only rose up to full height leaving the front right down! After a while, the front majestically rose up and the car settled to normal height.

Unplugged the Nanocom and left it feeling a little confused.

Will check it shortly but, what is going on....

If it has detected a height sensor out of range, it will log a fault and not try to do anything in case it damages things which probably explains why the pump isn't firing up. Use the Nanocom to check the readings from the height sensors at all heights. I suspect you will find a dead spot on the track on at least one.

Thanks for that Dave. I need to check that out. If I can get my brain around the Nanocom and its settings!

Parked it on a hill this morning. Before I exited the vehicle, the click click clicking was heard, and the car settled down low. Returned an hour later, started up and within 10–15 seconds it was up to normal Height, still parked on the hill, result.

The self levelling will drop 3 corners to match the lowest so if it settles down low, then one corner height sensor is reporting it is lower than it really is. I suspect if you'd looked closely, you'd have seen one corner sitting higher than the others, that will be the one with the iffy height sensor. If it rose normally on start up, the ECU hasn't detected that one is giving an out of range signal so it assumes everything is fine.

There's 2 pages on the Nanocom that will display the live readings from the sensors. On the Settings page you have to click on a button to update but on the Inputs page it shows target heights and actual in real time. If you start with the car at Access and tell it to go to High, you'll be able to see the numbers rise steadily as the car rises. You are looking for a sensor that either hangs at a certain output or suddenly jumps.

Thanks for that advice Dave.

Car playing about today. Parked up for 20 minutes on level ground, Car decided to settle and then it wouldn’t rise to ride height which was really annoying.

Going out to the garage now to see if I can figure this out.

Car on level ground. I am on utilities. Trying to go from access to standard. It states that the front left and front right valves are closed and the rear left and rear right valves open.
Compressor is off, exhaust valve closed, inhibitor switch off. Also states the inlet valve is open and the thermal switch is hot

From a layman's point of view I am guessing the thermal switch shouldn’t be hot considering that the compressor isn’t running and the car has only had a very short 2 mile journey this morning.

Thermal switch will show open or closed. Should be closed if cold and open if it has overheated (or the thermal switch has failed). If the switch has failed, poke a piece of thin wire into the back of the connector to short between Orange and Black wires at the pump to simulate the thermals switch being good. It will always open the rear valves first, wait until the rear has lifted, close them and then open the fronts.

Start by clearing the faults and running the pump to get it to start working, then go into inputs and look at what the height sensors are showing you.

Dropped it down to access height.
Front left is 3 mm above target front right is 6 mm below target.
Rear left is on target and rear right is 2 mm below target.

Set to standard. Both the front right and rear right are slower to rise.
Front left is 4 mm above target. Front right is 1 mm below target.
Rear left is spot on, rear right is spot-on.

Set to High. Again, both front and rear right are slower to rise.
Front left is 3 mm above target. Front right is 7 mm Below target.
Rear left is spot-on. Rear right is 2 mm below target.

They all take a minute to settle, and don’t go immediately to the correct setting.

A few months ago. I renewed both front sensors with pattern parts.

The rear is still running its original 22-year-old sensors.

Would it be worth spending the money and buying four new OE sensors?

I really appreciate your help so far Dave.

By the way, I have left the cover off the pump and the thermal switch reads normal. Don’t know if that has anything to do with it.

If the thermal switch reads normal, that is good. I couldn't remember if it reads Normal or Hot or Open and Closed. If it is iffy, that would cause the pump to not switch on whenever it is showing hot. It may be a dying sensor or it could be a dry joint where it is soldered onto the pcb.

Pattern height sensors are well known for having a very short lifespan, secondhand originals from a low mileage car are a more reliable bet. The numbers aren't mm but bits, the sensors give a reading of between 40 and 225 as the wiper moves from one end of the travel to the other. You need to watch what happens as it moves between heights and look for jumps or intermittent obviously incorrect readings. So if it is moving from 90 to 110, it wants to stay in that range and not suddenly read 80 or something else obviously wrong partway through the movement.

Although not mentioned in the EAS System Information Document (see https://drive.google.com/file/d/1eHSEP_2OsOFxYZh-MgevIVRsDg5Tel2u/view?usp=sharing) word has it that the target settings at all heights need to be within a certain limit (6 or 8 bits) side to side and have to be within the acceptable range for the height (page 32 of the document).

Again, thanks.

Every bit of information is useful!

What seems to happen on a more regular basis is, for instance, after using the car this morning and switching off at standard ride, I have it on a dead level floor, I started it up a short while ago, instantly on standard ride height, good.
Sent car down to access height, car instantly went down and settled at access.

Switched to normal ride height, nothing happened. Checked pump and it isn’t running. Left it for awhile, nothing. Went into settings and switched pump on manually. After a while, the rear comes up, followed by the front and then back to normal.

It seems that when the system calls for the pump to switch on for some reason it isn’t.

Not sure where to go from here. Very frustrating!

Does the Nano show that the pump is on when it actually isn't? Is it pulling in the relay but the pump doesn't start? Are the contacts on the Maxi fuse clean?

Stuff I will check tomorrow, thank you…

Have you actually checked the pump output ? Leave drivers door or tailgate open. Then clear all faults & run the engine. Pump should run until the tank is full & triggers the pressure switch. If the pump cannot fill the tank it needs a refurb.

It could also be dodgy brushes inside the pump, or even an intermittent thermal sensor connection. The sensor wire is crimped to a tag on the PCB which can fail. All of my pumps have it soldered inside !!