EAS, mind of its own!

[Robsrod 58]

Hi all,
I recently overhauled my 2001 P38 EAS valve block courtesy of "Paulp38a" excellent post.( no leaks )

I then set about recalibrating the heights using "EAS Unlock" basically to level out the car, but i did reduce the highway mode by 10mm. Everything fine for first couple of days until the wife and I went to the camping show at Rosehill, when the car started to go up and down at the front like some sort of "pimp" mobile in standard mode, (embarrassing! ).

To over come this I set it to highway mode and all seems fine. I'm leaning toward height sensors as the culprit, but i find it more than strange. Needless to say the compressor is going out of its mind playing pimp.

Any help from you kind folk in diagnosing this would definitely help me from going out of my mind!!!:confused:

[Hoges]

check out this fopr correct calibration procedure
http://www.aulro.com/afvb/p38a-range-rover/125765-height-limits-eas-using-faultmate.html post #3

The EAS ECU has inbuilt algorithms which calculate the specific heights from the sensor bit counts and sets the relativities between them... once you go outside the boundaries of the default settings you can get the sorts of behaviour you described. you can make alterations to all the heights...e.g. raise/lower them all by 10mm and maintain the relativity ...but making individual significant changes causes "mayhem"!!

If everything is absolutely set to standard and the valve block is ok but there are still issues, the EAS driver block which is bolted to the valve block may be the culprit. Its electronics are sealed in resin which tends to break down with the heat and ultimately the Driver's performance deteriorates...

If you need a replacement, check out the prices from Airbag Man here in Qld and compare them with the usual UK online suppliers...

cheers

EDIT on re reading your post, you may have issues with the check valves... if you put lubricant on the tiny o-rings to assist their proper seating...it will cause them to leak resulting in the front end rising to max height. They must be totally dry and free of any grease or other contaminant to seal properly

[redandy3575]

I'm having similar problem now after i replaced the rear left sensor with a new one. Can anyone tell me if on the left side the link arms are meant to face forward or rearward. I can't remember after taking off the old one.

Also does the fact that i've got a newer type sensor on the left over an older on the right cause conflict at all?

[Hoges]

I'm having similar problem now after i replaced the rear left sensor with a new one. Can anyone tell me if on the left side the link arms are meant to face forward or rearward. I can't remember after taking off the old one.

Also does the fact that i've got a newer type sensor on the left over an older on the right cause conflict at all?

Elbow join of RL sensor arms faces to the rear as does that of the RH rear. AFAIK all sensors work on a 0-5V range so there should not be any difference ..but you should recalibrate it as per the post mentioned previously.

If the front is rising randomly, I'd be examining the check valves as well as making sure the respective solenoid o-rings were properly seated and that the "pistons" were put back correctly

[Robsrod 58]

check out this fopr correct calibration procedure
http://www.aulro.com/afvb/p38a-range-rover/125765-height-limits-eas-using-faultmate.html post #3

The EAS ECU has inbuilt algorithms which calculate the specific heights from the sensor bit counts and sets the relativities between them... once you go outside the boundaries of the default settings you can get the sorts of behaviour you described. you can make alterations to all the heights...e.g. raise/lower them all by 10mm and maintain the relativity ...but making individual significant changes causes "mayhem"!!

If everything is absolutely set to standard and the valve block is ok but there are still issues, the EAS driver block which is bolted to the valve block may be the culprit. Its electronics are sealed in resin which tends to break down with the heat and ultimately the Driver's performance deteriorates...

If you need a replacement, check out the prices from Airbag Man here in Qld and compare them with the usual UK online suppliers...

cheers

EDIT on re reading your post, you may have issues with the check valves... if you put lubricant on the tiny o-rings to assist their proper seating...it will cause them to leak resulting in the front end rising to max height. They must be totally dry and free of any grease or other contaminant to seal properly

Thanks Hoges, The only grease I used was "Inox", sparingly, and also not on the check valves.
The problem is not a leak as overnight its very stable, so I'll bring everything back to as close to standard and see what happens. It just seems strange it didn't do it straight away.

Rob

[benji]

Rob, it's most definately one of, or both of the front height sensors. Basically the ecu isn't getting a valid signal so it goes searching for one by pumping the effected corner up and down. Front ones IME are the first ones to go, maybe because of the heat. Your back ones may be fine for another 5 years or so, so don't change them all. If it were your valve block, it would be raising and lowering the front at all height settings.

Your lowered HWY mode seems fine; if you did go to low, or too high for that matter the ecu reverts back to the previously stored heights (well that's what it did to me anyway). How does it ride at the lower setting?

Redandy, having different height sensors (even old classic ones) with new ones etc are fine. Different model height sensors seem to be slightly different in terms of resistance, so you'll need to recalibrate that corner. I had a sensor off a 2000 on my classic, and once I recalibrated the height settings (and they were drastically different) it worked fine.

[redandy3575]

Talk to me more about recalibrating?, are you revering to adjusting the height or something else? Can this be done with a kicker?

[Robsrod 58]

I've just spent my Anzac day going over what I did when I o/hauled valve block. I checked the solenoids on the top of the valve block, guess what I found, the stupid bugger (me) that put it together swapped one of the actual pressure part of the valves around, so that one of the front airbag valves was different to the other.:wasntme:
I checked all the top valves after correcting my error, all Ok checked height setting with EAS unlock and made minor adjustments to normal height ( all well within standard range), took it for a reasonable test drive with fingers crossed, and all good for the moment, even the pump seems happy!

If this was the fix, the culprit must have been leaking air into the airbag and the other one was playing catchup until, EAS said "too high" and dropped the front back down to normal height, so starting the whole process off again, hence "pimp mobile". Does that sound logical?

Rob

[Hoges]

Talk to me more about recalibrating?, are you revering to adjusting the height or something else? Can this be done with a kicker?

Recalibrating is rewriting the bit counts in the EAS ECU memory so that the ECU sends the vehicle to the correct height ...I don't have a 'kicker' but AFAIK it does not allow for recalibration...it simply reads memory for faults and clears them...unless they are the result of some mechanical malfunction, in which case they can't be cleared properly until the underlying cause is fixed.

[PaulP38a]

Rob - glad to hear you found the culprit. Did you accidentally swap the internal solenoid plunger for one of the Exhaust or Inlet solenoids? The Inlet and Exhaust solenoid plungers are a large-ish rubber foot while the air spring solenoid plungers are rubber inserts within a brass ring.

Redandy and Hoges - The EAS Kicker (not the Kicker Lite) will allow re-writing of EAS values to assist with recalibration. I have tried it and it works, but I prefer the EAS Unlock Cable with RSW Solutions' EAS Unlock Suite.

Cheers, Paul.

[Robsrod 58]

Yep Paul, thats what I done!
I will follow up next week after a solid week of driving to work, But I'm mildly confident.

Rob

[redandy3575]

Redandy and Hoges - The EAS Kicker (not the Kicker Lite) will allow re-writing of EAS values to assist with recalibration. I have tried it and it works, but I prefer the EAS Unlock Cable with RSW Solutions' EAS Unlock Suite.

Cheers, Paul.

Ok, i've taken the sensor off again and re-aligned it. I noticed that the sensor came with a seperate bracket that mounts the sensor in a certain angle, as soon as i re-mounted it, the sensor value matched all the other sensors and all is good now, except i discovered a leak at the valve block which i quickly fixed, then noticed the vehicle raising much too slow and the compressor constantly cutting in & out. Upon closer inspection and dismantling the compressor noticed the piston seal worn. So on the computer i go and order a new seal & piston chamber off Paul ( HardRange), re-assembled compressor temporarily and still drivable til the parts arrive.

[PaulP38a]

RedAndy - just sent you an email about the cylinder and seal. There might be a quicker way to get them to you for the weekend.

Cheers, Paul.

[Keithy P38]

Loaner compressor eh ;-)

I am running two factory compressors in series on mine as a safeguard in the event one decides to pack up! Made a habit of checking the flow from each one on a 6month basis!

Cheers
Keithy

[DT-P38]

Yes, yes,yes! Don't forget we VIC-AULRO'ians have access to a spare compressor if you want to borrow and rebuild it first.

You can then just do the swap out and give me back your old one.

I also have your bush kit ready and refund happening when you let me know account details (or could do cash if we can hook up some time soon).

[Hoges]

Loaner compressor eh ;-)

I am running two factory compressors in series on mine as a safeguard in the event one decides to pack up! Made a habit of checking the flow from each one on a 6month basis!

Cheers
Keithy

That's impressive! Do they both start at the same time triggered by the pressure switch?

I've been wondering about the feasibility of blanking off the pressure switch hole in the valve block and relocating the switch to the main tank...don't know if this is realistic. In the grand scheme of things I'd also consider relocating the whole setup to the space where the jack etc is located in the wheel well ---am sorely tempted. :confused:

[DT-P38]

Hey Hoges,

That would make dual battery wiring and snorkel plumbing solutions much easier to fit in.

Dave

[Keithy P38]

That's right, second compressor runs at the exact same time as the other factory compressor. Has its own wiring, fuse and relay! It's triggered off the main compressor start/stop wire (I had it wired up by an auto leccy).

I have photo's, etc but can't upload them because I'm using my iPhone until Wednesday!

Cheers
Keithy

[zhoey]

I've been wondering about the feasibility of blanking off the pressure switch hole in the valve block and relocating the switch to the main tank...don't know if this is realistic. In the grand scheme of things I'd also consider relocating the whole setup to the space where the jack etc is located in the wheel well ---am sorely tempted. :confused:


I did think of that too ie. relocating the compressor setup to the wheel well.

This would probably reduce the heat build up in the EAS box by up to 90% probably the o-rings and any rubber & plastic components in the valve block would last a lot longer.

And of course there is the possibility of using a compressor with a higher flow rate......I was already looking at the OEM ones from Mercedes Benz or even BMW's. I would imagine that it would be best then to run an aluminum or a copper pipe between the compressor and the air tank.

Any ideas on how to mount the pressure switch on the air tank though?

[Hoges]

I 'm trying to rationalise the trade off between expected ( improved) reliability vs ease of access ..i.e. simply raising the bonnet vs having to empty the load space to remove the wheel well cover...

Re the pressure switch: I'd take advice about simply drilling the end cap of the pressure cylinder, and tapping it to accept the pressure switch.

The harness would be relatively straight forward - run a multicore cable internally (under the carpet and door sills). There are grommet holes already in the rear under panel for 6mm nylon pressure tubing. Mounting the whole box and dice on a rubber pad ought damp the noise/vibration nicely;)

Could then mount the emergency bypass Schrader valves somewhere on the end of the side panel which encloses the subwoofer...

I obviously have not got enough to do...or I'm escaping domestic chores...hell isn't that why we have P38s?:eek::p

EDIT: It just occurred to me that maybe the valve block and drive box are relocated while the compressor remains in the engine bay...was thinking about aircooling which would be non-existent in the wheel well ...cos mine doesn't leak anymore:p

[zhoey]

I 'm trying to rationalise the trade off between expected ( improved) reliability vs ease of access ..i.e. simply raising the bonnet vs having to empty the load space to remove the wheel well cover...

Re the pressure switch: I'd take advice about simply drilling the end cap of the pressure cylinder, and tapping it to accept the pressure switch.

The harness would be relatively straight forward - run a multicore cable internally (under the carpet and door sills). There are grommet holes already in the rear under panel for 6mm nylon pressure tubing. Mounting the whole box and dice on a rubber pad ought damp the noise/vibration nicely;)

Could then mount the emergency bypass Schrader valves somewhere on the end of the side panel which encloses the subwoofer...

I obviously have not got enough to do...or I'm escaping domestic chores...hell isn't that why we have P38s?:eek::p

EDIT: It just occurred to me that maybe the valve block and drive box are relocated while the compressor remains in the engine bay...was thinking about aircooling which would be non-existent in the wheel well ...cos mine doesn't leak anymore:p

Must look at the viability of mounting behind the rear bumper or in the space where the subwoofer used to be. I believe Mercs that have air suspension have compressors mounted behind the rear bumper.

[Hoges]

Must look at the viability of mounting behind the rear bumper or in the space where the subwoofer used to be. I believe Mercs that have air suspension have compressors mounted behind the rear bumper.

hmmm... wonder if they're water tight...

[redandy3575]

Dave & Paul, thanks heaps for your help in delivering the parts on such a quick time frame, very much appreciated.

[zhoey]

hmmm... wonder if they're water tight...

As I understand.....yes.

[benji]

Yes the pumps are water proof (with an extended air intake), as with the rest of the eas stuff. I've had mine running underwater many times on the classic - never caused an issue.

The ecu is also water proof ..... :angel:

Was looking under the bonnet yesterday thinking the same thing; then I could fit a second battery in the engine bay.

[Keithy P38]

For an easier swap I was looking to move my eas gear to the airbox's current location and put my air intake in it's place ready for a custom stainless snorkel!

Keithy

[Robsrod 58]

That's right, second compressor runs at the exact same time as the other factory compressor. Has its own wiring, fuse and relay! It's triggered off the main compressor start/stop wire (I had it wired up by an auto leccy).

I have photo's, etc but can't upload them because I'm using my iPhone until Wednesday!

Cheers
Keithy

Keithy P38,
Have you thought of incorporating a "flip flop" circuit for your 2 compressors, using just 2 relays and a capacitor, that way every time a compressor is switched on they alternate operation. I've tried to upload an attachment of the circuit, Courtesy of J. Flavell, but being new to forums I don't know if it worked:question:

It did.

Rob

[Keithy P38]

I did think about it but I wanted both to run equally, more-so for tyre inflation than anything else! I regularly deflate and reinflate!

[benji]

I had a similar setup on my classic, I just upgraded the pump relay and ran both compressors off that. I also put in a switch to turn the pumps on manually, and an led to tell me when they were on.

Also a switch that put a door open signal, and another that turned the power off to the ecu. I used them heaps!

[Keithy P38]

The door open switch sounds like a winner!

[benji]

I mainly did it to fit in my shed with the roof rack on, but found so many uses for it.
The p38s can drive around on access anyway, but would be usefull to freeze the system for working on it etc. and very usefull for heavy offroad work, where your cross axled and the eas would take air out of the dropped bag, or to stop the system going into extended mode so you've got more usefull articulation.
The power cut to the ecu was usefull for catching soft faults quickly, and locking the system in high. The power can be flicked off and on at any speed with no issue.


It was the start of an auxilary air system that was to use the bullbar as the tank, but never really got to that stage.

[DT-P38]

The door open switch sounds like a winner!

X2. As long as you could still lock and alarm car (which would be a TBC I guess) it could kill off self leveling.

[Robsrod 58]

Its now been a week after having the EAS block overhauled and all is good, no great. This is truly a good system if you know what you are doing.
After assessing the wear on the "O" rings and the operation I'm not convinced all of them need changing on a very regular basis, when you consider that on the whole block, only 3 would be considered "dynamic" ( check valves ) and all the others are static, or non moving, so the only reason to replace them was if you had to replace a solenoid piston etc or a leak from the external connections due to vibration, possibly. with that in mind I've read that it was suggested that the block be o/hauled every 2 years.
I would think that the check valves YES 2 years max and the rest anywhere from 5 years to 10 years or failure. By disturbing static O rings for no good reason is only inviting more possible troubles.
I'd like to throw this out there for more comment.

Rob

[PeterAllen]

I agree with you. Having pulled mine apart about a dozen times after the past I had not come across many of the o rings that were brittle or obviously stuffed. I have kept most of the old ones anyway and will only strip it down if it has a problem. I replaced three airbags (one was a definite leaker and one suspect). driver unit (unneccesary as it turned out) and pressure switch that was intermittently causing problems. Main solenoid problems came from the 4 airbag solenoids for me and not an issue with the Orings. It was all about the rubber caps and bottoms on the internal pistons. But now its all working and I am a lot more clued up on its intricate workings and love it, plus have the confidence now of taking it all apart where ever I may be.

[Robsrod 58]

Are the pistons under the solenoids available to purchase, as these are also dynamic items also prone to wear on the sealing surface.

[PeterAllen]

Not that I have found, I just had to lightly sand the bottom rubber with wet and dry sandpaper and superglued the top rubber cap into place on each piston. Seemed to work so far but would be handy to have new replacement ones if they were available.

[DT-P38]

All fair comments, but if your going to the trouble of pulling it down why wouldn't you refresh the lot?

I found that a number of the rings looked ok shape wise but were dry, stiff and ultimately cracked when I gave them a bit of a squeeze. No doubt the result of 17 years under a mostly hot and dry P38 clamshell.

For the negligible extra cost and time involved (and especially for first timers/novices) I would say "Nike - just do it."