p38 air sus problems strange ones!!!

Hi, i have a 2000 (w) p38 4.0 hse model. The air sus has been playing up for the last year and landrover are being totally useless and costing me a fortune.
My rangie keeps putting itself on the wadeing setting while driving! You can go down the road at 70 mph on wadeing setting or the highest setting (not sure what it's called).
Fistly the dealer calibrated the sytem, the system was showing no faults whatsoever. That did not work so they changed all 4 of the height sensors, this also did nothing to cure the problem. Then they said "ohh it must be the air sus ecu unit". I had them change this and recalibrate the system again but still no joy.
I can start the vehicle up and the air sus will go to the correct level, i go two minutes down the road and she goes up the the high setting again. Now it will come down to normal height if you press the button. Before we had the ecu fitted you could drive at any speed on the highest setting and it would not try to put itself down. Now the ecu is in, if you put the vehicle on the wadeing height and go above 35 mph she will go down to the normal ride height as it should according to the manual.
Landrover seem totally lost to find the fault and their responce has been time and time again "well it's costing you so much in labour you may as well start replacing parts" !!!!! Great. Now they seem to have no idea what to replace next as the valve block seems to work fine as does the compressor.
Can anyone help me with this issue?

DAVID

Maybe the car is lifting up its skirts trying to give you a hint to get into some water. Range Rovers die if you keep them on the road without letting them play.

thanks mudflap but it doesn't really answer the question i asked! The vehicle is useless and unsellable unless i can solve this issue!

DAVID

When you say you have changed the ecu, which one, was it the one under the passenger seat or the ANR3900 drive-box adjacent to the valve block.
You may also find this site helpful,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Range Rover Air Suspension solutions by Rover Renovations.

What about spurious signals coming from the dashboard switch which could be faulty, or the wires in the cable loom itself? An easy check would be to disconnect the dashboard switch and try it out.

Seems odd though, will the system allow you to drive at High level above 50mph, I don't think it will? Definitely not without giving you warnings and bleeps.

There is High level, and then Extended level; the Extended level cannot be requested, it is only reached when the ECU detects you are stuck and tries to help out by raising the vehicle further. I imagine if you were getting to this height at 70mph it would be a noisy, meandering and scary ride!

Hi, right to answer the questions you have asked:

I don't remember the ecu part number and i didn't fit it, all i know is that landrover said their computer would not talk the the ecu when they were trying to calibrate the new height sensors. With the new ecu in place they calibrated first time.

As for the ride height, with the inhibit button on you can reach the extended height for wadeing. If the suspension is left to it's own devices (no inhibit buttom on) it puts itself at the extended level every now and then for no reason. It will come back down if you press the height button and tell it too but before the new ecu was fitted you could drive it at 80 mph on extended height and it would not try to correct itself! Making it seriously dangerous on a motorway.
The valve block is 8 years old from new, does play up a little like slow to drop sometimes but it does work fine and has been like it from new.

I drove it under half a mile the other day and it went to extended level after going round two corners, it's so unpredictable somedays it's fine then others it will go up to or three times on a half hour drive.

Futher to the last post i drove the rangie 12 miles leaving the suspension to do whatever it wished to do. On coming into a small town the rangie decided it was time for extened height mode again however, instead of iiluminating the normal ride height light on the switch and flashing the extended light it just flashed the extended light on it's own. I continued to drive around the town at speeds under 30mph to see what happened. After around a mile it was still flashing the extended light on the switch, i pulled over to see what height it was at and found it to be on the correct extended height level (although according to the dash switch it had not yet reached the correct extended height) as the switch was still flashing. I continued to drive throught the town and approched the end of the speed limit. Not wishing to have a burnt out compressor i pulled over to open the bonnet and see what was happening. As i opened the door the eas height switch started flashing the normal ride height and extended ride height lights alternately. I opened the compressor box to find the compressor a little hot but nothing to worry about. By the time i had shut the bonnet the rangie had returned to normal height of it's own accord and drove home perfectly.
This is driving me insane as it has no ryme nor reason to the fault, help help help or i'll have to set fire to it and claim on the insurance!!!! (joke)

hmmmm wierd , it may be a long shot here but try changing the compressor relay , mine played up and you would not believe the antics it got up to , eventually it buggered up my new compressor .
it may not be that thats at faunt but for 2 mins work swapping it over for another its got to be worth a try .
as for your local landrover dealer well to be honest with you i would have the right hump and i`d be thinking about kicking some ass , if your happy to sit still for their shoddy work im sure they will be happy to blow smoke up your ar*e all day long , it must have cost you a small fortune up to now and still not right .........................flex your chest muscles mate and tell them which way is up!!!!!!!!! , also tell them you`ve paid enough and dont expect another bill !!!.
rick.

Rick,
Thanks for the heads up on the relay. At the moment i have removed the dash switch to see if it may be sending the ecu the signal to go up by accident. I will run it round today and if she still goes up i'll know the switch is ok, i'll try the relay after that! The valve block and compressor were working perfectly this morning anyway.

DAVID

Further today, rangie went onto extended height no more than 300 yards from my drive with the eas dash switch removed, therefore telling me the switch is not at fault! Will change the relay or relays tomorrow morning before going for another valve block and compressor.

Further on again today. Changed the air sus relay in the fuse box (thanks to rick for the heads up), have driven the rangie for around an hour all over the place and played with the suspension up and down on differant heights. No problems are now showing up and the rangie has not yet tryed to put itself onto extended height. I pray that it has now been fixed. Will try it all this next week to see if we have cured it and then see about getting my money back from MARSHALL LANROVER OF PETERBOROUGH.

DAVID

great stuff david , im glad i could help as i said earlier a couple of quid relay can play all sorts of weird and wonderful tricks on the eas and are very often overlooked by the dealer because it doesnt show up on test book or autologic .
i found my relay faulty after it played tricks for a couple of weeks , my local independant guy who`s a top class landy man and lets me use his autologic f.o.c was scratching his head same as myself ................no faults showing , then it just happened that the compressor carried on running when everything was turned off the only way to stop it was either unplug the compressor or the relay , we the swapped over the relay and bingo its been right ever since .
unfortunatly because it had been faulty for a couple of weeks it had buggered up my 2 week old compressor it must have been switching on and off when left parked up .
anyway i hope thats an end to your problems , and good luck with chasing the dealer for some kind of refund .
rick.

Rick,
I had a trouble free day of rangie driving yesterday, did around 30-40 miles over all terrane and at differant speeds also playing with the height, no faults as yet. I swapped one of the heated window relays with the eas one, will go to landrover and get a new one today, another test to see if it fails on the journey! I can't thankyou enough if this has indeed fixed it, i'll leave it a week before writing to marshall to pleed my case.

DAVID

Well here we go again! 15 mile drive to landrover and we are back on the old extended height another 3 times! It failed again right outside the landrover garage and so they pulled it in and put it on the computer which again showed no faults at all!
They have now said that they will consult the head technicians at landrover to see what they can do as they are out of ideas. i hold out no hope for this as the mechanic said they would be lucky to find anyone there who had even driven a p38 let alone knows what to do with dodgy eas. Maybe the old petrol can will be coming out sooner rather than later to fix this once and for all!

David,
Sounds like you have money invested in the Dealership so it might be worth your time to get some free service from them. But in my opinion, I would stop dealing with the dealership and begin diagnosing the system yourself. I would make yourself or purchase an EAS serial cable and use the free software to keep an eye on the EAS. Range Rover EAS Reset Tools

Am I correct in stating that you have never had an EAS Fault triggered with all of the random raising of the suspension events? Also the raising of the suspension is independent of the speed at which you are traveling? You also stated that the Dealership was unable to connect to the EAS, is this still true? All of your problems are so spread out, it seems that this might be a wiring loom issue or a ground issue.

If you send the EAS to the extended height yourself, will the suspension lower when you go over the 35 mph limit?

Heres a couple of ideas.
1, check the output fro the alternator. You should have about 14.4 V at the battery with the engine running, anything else could upset the ecu`s.
2, Check the main fusebox connections. These suffer from dodgy connections after 5/6 years. Various expert recomend this is changed as a matter of course after this time to prevent strange electrical occurances.
3, Consider a leaking valve block. New diaphrams are now freely available- so consider re-buiding your own. Plenty of people on this forum and here have done thisRangeRovers.net :: View Forum - Range Rover 4.0/4.6/P38A Forum

My gut feeling is the valve block, if pressure is leaking past the inflate valve, it stands to reason its going to go up. The ecu will register the hight change and illuminate the upper level light....

Share your findings .

Hi again, thanks for all the posts trying to help out on this issue.
To answer some of the questions, you can put the rangie on extended height yourself and it will lower after going over 35 mph. The new ecu now talks perfectly to marshalls computers but still stores no faults whatsoever even when the fault occurs when their computer is hooked up to the system!
If the vehicle puts itself on extended height it only flashes the extended height light on the dash switch, it does not keep the normal height light illuminated and flash the extended one as it should. When it does this fault you can drive at any speed and it will not lower, i've been doing 80mph when it's gone up on the motorway! If you continue to drive when the fault shows up it will clear and lower after a few miles of it's own accord. When it goes up you can press the dash switch and tell it to go to normal ride height and it will try to, sometimes it will go down other times it just reverts to flashing the one extended height light and remains on extended height.
As for valve, it generally works perfectly although on the odd occasion it does stick a little, the compressor is still fine and has not been changed since it was new.
When i spoke to marshalls about changeing the valve block the mechanic said he had been there for 10 years and only ever changed two of them, and he's in charge of eas issues.
The rangie is now booked in wednesday next week and they are speaking to landrover to see what tests to put it through to try to find what's causing this issue. I believe this diagnosis is going to be free but expect them to come up with again a few expensive parts that it might be. It's in for 3 days.
As for rebuilding the valve block myself i'm afraid i'm just not confident enough to try this, if i break it you know how much these things are.
I am now wondering if ayone has a old vavle block i can fit maybe with another fault differant from this one? See if the same fault occurs with another block and that would either show it to be the fault or take it out of the equation.

DAIVD

Try and get them to try a new drive box (ANR3900) I don't believe problems with this cause faults to appear.

Thanks mate, i've just spoken to a long term marshall mechanic who i know who has his own company dealing with these vehicles now. He suggested the drive box and also changed the fuse box as they degrade! Aparantly the drive box controls whatever the suspension does and talks to the in car ecu however, should the drive box be faulty or be getting an earth it should not be getting it will open the valves and put the rangie up showing no faults on the other ecu. It's a long list of maybe still at the moment and it's costing me big time. Drive box is around £160 + fitting.

I had a similar experience with mine going up to wading height often enough. But mine used to fault out too after a while. I got a kicker to read and reset the faults. I was getting a pressure switch fault which actually means either the compressor is worn out or possibly the driver is faulty. The advice going was the first thing to do is check for leaks, then check for more leaks (of which I had a few, mainly where the pipes go into the blocks - fixed with new o-rings) and finally start looking elsewhere. After much browsing of the discussions on rr.net I too suspected the driver and I went about sourcing a second one to swap it over. In the meantime Dennis (Shupack on rr.net) sent me a replacement sleeve for the compressor which I fitted and the EAS has run faultlessly since doing the compressor without swapping the driver.

Bottom line is you can do alot of checking without handing over money to the dealers, who judging what they've done so far, have made quite a bit of money out of you. Doing the o-rings is a really simple operation and doing a compressor re-build is not that bad either. Check out roverrenovations.net, I've found them really good.