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Discussion Starter #1
So my EAS is giving me nothing but headaches. The problem is this...the front suspension is rising up and down as if commanded to by some unknown gremlin. Often goes like this: compressor will run for ten or fifteen seconds, shut off. Then the front suspension, together, will sink through normal means...the valve block will click and it goes down two or three inches. Then as soon as it goes down, the compressor will turn back on, and the cycle repeats. It is constantly hunting for level height in both standard and highway mode.


It will do this if the brakes are applied or the tailgate is open!

I've been working with a local enthusiast shop who it seems are just as stumped as I am. So far we have replaced a height sensor (RF to LF and installed new in RF) as well as driver pack and EAS ecu under the driver seat. I guess all that is left is the valve block, but if it were a leaky valve block you would think it would act like a leak, and not lower as it was designed to do!!
 

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2006-2009 Range Rover Sport
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I recently had very similar issues with my Rover with me going crazy. I rebuilt valve block, replace solenoids, cleaned/reseated front bags and tried a lot of other things. But at the end I found out the front air bags were leaking at one particular height. If EAS was able to go past the height or stayed under that leak, it would hold fine. But sometimes it will do exactly what you are describing above and I would get FL/RF Value stuck open errors sometime.

I even checked the bags which looked just fine, but after replacing both front bags everything is good. You may want to try inflating and de-falting front bags manually either using EAS software or pig tails method to check for possible leaks that could be confusing EAS.
 

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It does sound like a leaky bag. The computer is adjusting to the leak making the monkey dance! Your shop doesn't sound like they are doing anything more than replacing parts. ECU's almost never go bad but get replaced a lot. Ask for your used parts back since they are fine and you can ebay them to recoup some cost.
 

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Discussion Starter #4
Valve block has now been replaced and the bags inspected. No leaks found. Because the truck will adjust with the tailgate and door open we now think it may either be a wheel speed sensor (front springs adjusting from standard to highway and back again) or BECM. Not much left to go to after all suspected parts have been replaced. Any further ideas?

The main symptoms: the truck will sink to the bumpstops within a couple hours, but not every time. It seems to be at random. After 5 or 10 minutes when you start the truck on the bumpstops, the compressor will fill the tank, but if you try to raise it the compressor will turn back on to raise the suspension if it had turned off. Then, once it self levels, within a few seconds the truck will drop from what seems like standard to highway mode. It drops by the valve block clicking like it is supposed to. Something is telling it do it. THen after it drops, the compressor turns on (even if the tank is full, or should be full) and raises the front springs back up to where they should be, and the cycle repeats.

So far the height sensors have been replaced, driver pack, EAS ecu, valve block, and four new springs.
 

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LEGACY VENDOR
1995-2002 Range Rover P38A
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If the truck is adjusting itself when there is a door/tailgate open, I can't think how that would lead to the thought of it being a wheel speed sensor? I would have thought that it would point towards the fact that the ECU isn't getting the "door open" signal..

This comes out of the BECM on C1288, pin 3 - Green 16 way connector. Wire colour is Purple/Orange.
This splits and goes to the EAS ECU on C0867 (at the EAS ECU) on pin 34. It also goes to the delay timer/relay - on C0866, pin 5.

Have you checked the delay timer in in place, and none of the connections are corroded? Have you tried swapping the delay timer for another one?

Cheers,
Marty
 

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Discussion Starter #6
I have not checked or replaced the delay timer. That may be a seperate issue, but I'm still not sure how that would address the main issue at hand, the suspension cycling...will check the timer next.

Will also add that while in drive and coming to a stop, if the front suspension has cycled down, while on the brakes and slowing the front will rise. Correct me if I'm wrong, but it should not move at all with the brakes applied?


If the truck is adjusting itself when there is a door/tailgate open, I can't think how that would lead to the thought of it being a wheel speed sensor? I would have thought that it would point towards the fact that the ECU isn't getting the "door open" signal..

This comes out of the BECM on C1288, pin 3 - Green 16 way connector. Wire colour is Purple/Orange.
This splits and goes to the EAS ECU on C0867 (at the EAS ECU) on pin 34. It also goes to the delay timer/relay - on C0866, pin 5.

Have you checked the delay timer in in place, and none of the connections are corroded? Have you tried swapping the delay timer for another one?

Cheers,
Marty
 

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LEGACY VENDOR
1995-2002 Range Rover P38A
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I'm not sure how it would affect the main issue either - but it just seemed strange! Likewise, the raising up under braking sounds like the ECU isn't getting the signal from BECM etc that the brakes are applied..

I will have a look a bit later and see if I can find the wire that sends that signal...

You've replaced all of the common components that fail, so starting to run out of ideas! Have all of the parts you've replaced been second hand, or new? I presume they are all tested and working?

Cheers,
Marty
 

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Discussion Starter #8
Thanks Marty! On the drive home tonight I was thinking what about a massive air leak in the front air lines..because they have not been replaced. But if there was a leak in the lines, it would not explain why the valve block is working to lower the springs...as in clicking and releasing air to let them down.
 

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JACK'S GRANDAD
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Was the driver and ecm used?
May have got a bad one. I would vote for the driver pack myself.
When parking at night, pull the delay relay and see what happens. If it sinks, you have a leak, period. This could be the cause of the dancing issue too.
Have you sprayed with soapy water everywhere? Under the solenoids is an often missed spot (hint hint).
Sounds like the guy is swapping parts as already said, and there is no reason for it. Any codes turn up? Ability to look at live data, like the height sensors when its running?
If not, then you NEED the software to look into it. You will be able to see target heights and actual heights, then compare the two.

Martin
 

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Discussion Starter #10
All parts replaced have been used, but they came off a working truck. The parts were replaced one by one, and right now I have all brand new (used) parts. To be clear, the shop is fantastic and they have not/wont charge me until we get to the bottom of it. Even if the parts are used, it is such a specific and rare problem that it is highly unlikely that the problem would be reproduced on two units. Though I suppose anything is possible..tonight I will pull the delay timer and see what happens. Previously when I left the door open overnight I lost all air in the system and went to four bumpstops.
 

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Discussion Starter #11
Leftlanetruckin, question. Could a faulty delay timer cause this type of issue? Perhaps it is telling the ECU to randomly lower or just sending out garbled data? Or is it a simple timer that just wakes up the ECU...also, what about a faulty compressor. Perhaps it isnt producing enough pressure, and is getting turned off by the thermal switch before it develops enough pressure to fill the bags? Though the car does indicate that is getting to desired height levels...
 

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JACK'S GRANDAD
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Hmm, bad delay relay or compressor.....
AFAIK, the relay is just a relay, but with a timer built into it. I cant see how it would make the rig act weird, unless it was cutting power to the ecm etc, but you hear the solenoids clicking dont you?
A bad compressor should throw a fault eventually. You need some diagnostic stuff on there in my book.
A gauge for the tank, to show how long it takes to fill the tank from empty.
A scan of the live data on the height sensors etc. using either a shop tool, or Storeys free software.
The compressor kicking on and off when it raises the rig is normal. It's due to the location of the pressure switch on the valve block, and not on the tank.
Without the right tools, there will be limited accurate diagnostics going on. Pull the relay and see what happens, then post back. By the sounds of it, you will be looking at it every half hour or so until bed time tonight....:lol:

Martin
 

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Discussion Starter #13
Something very strange just happened to me. I went to start the truck to ensure it was at proper height before I pulled the delay timer, and immediatly upon startup the suspension sank all the way down very rapidly to what seemed like the bumpstops. More confusing, the indicator light on the dash REMAINED on standard right height. Confused, I quickly pushed it to raise to extended mode, and it went from the bumpstops right back up to extended. The indicator light showed a change from standard to extended. WTF
 

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JACK'S GRANDAD
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There was a "mod" a few years ago, where folks wired the delay relay to a switched power source to make it not self level etc.
I know that some folks did it, and ended up with a rig that either went all teh way up, or all the way down when the relay got power......hmmmm....

Martin
 

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Discussion Starter #15
Its funny I was just reading about that when I googled info about the delay timer. I am the second owner of this truck, and the first owner did almost zero maintenance to it, I really dont think he cared about it at all...it has very low miles because it sat at his beach house in the Virgin Islands. Point is I dont think he did any mods to it, and all the wires down there look factory. But perhaps thats an indication of a faulty timer?
There was a "mod" a few years ago, where folks wired the delay relay to a switched power source to make it not self level etc.
I know that some folks did it, and ended up with a rig that either went all teh way up, or all the way down when the relay got power......hmmmm....

Martin
 

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JACK'S GRANDAD
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Could be a bad timer, dont know as I have never had to replace one! I do know they are expensive for a relay though.
Try pulling it tonight and see what happens overnight to the heights.
Like I said, if it drops, you have a leak period.
If it doesnt drop, then we have an electrical issue going on.

Martin
 

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After EAS problems on my first P38, the first thing I did when I purchased my second one was to a install a MARS manual inflation kit and a pressure gauge plumbed the air tank line. Later came the Buddy Box reset tool. The combination makes diagnostics easy as you can see what going on plus resetting the ECU yourself. And if you end up with a electrical issue (like when my driver block went out) with no leaks, you can temporarily unplug the ECU and drive on manually filled bags. It only takes one un-needed replacement part to cover the cost of these items.
 

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Discussion Starter #18
Well I did not have a chance to pull the delay timer last night. But today I got another opportunity to see exactly what is going on. Pulling into the driveway I parked in front of the garage door with the lights on for a minute. After about ten seconds or so in Park with the engine idling the valve block vented the front springs down about an inch and a half. Then ten seconds later, the pump came on and pumped them back up to level height. I shut it off and went in the garage for a two minutes, and when I started it up the EAS indicator was showing that the truck was trying to get itself into extended mode. WTF

If the driver pack, ECU, valve block and height sensors have been replaced, what the hell else could be telling my suspension what to do>
 

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JACK'S GRANDAD
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Relly sounds like either a driver is bad, or the valve block needs rebuilt. I vote a bad driver as that is typical symptoms of one going bad.
Try another driver, they do go bad and the newest (used) ones are over 10yrs old after all.

Martin
 

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Discussion Starter #20
At the shop now. Target and actual heights seem good. The suspension is moving with the doors open. A ghost command is opening and closing the valve block without us telling it to do so. Otherwise they say "closed" but they are being commanded to "open" randomly. Suggestions? We are checking the delay timer wires right now
 
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