P38 EAS random problems

[Boblofty]

Looking for some help guys. 2001 P38 AES. Just out of the blue it has started doing the weirdest things. Sometimes when the engine is shut off it will chase it's tail trying to self level until it is on the stops. Sometimes it wont.
Some mornings it will be down completely on the right hand side....sometimes it wont. Other mornings it will be down at the back...sometimes it is not.
On just the odd occasion it will be perfect and act as it is supposed to and performs perfectly on the road in all aspects.
What have I done so far.
I have replaced the computer.
Rebuilt the valve block (twice)
Eliminated all and any leaks.
Rebuilt the compressor.
Changed the sensors side to side back and front.

The weirdest thing of all is that it will run happily out of shape (in any configuration) until it 'alarms' out (which it doesn't do all the time) it will then reset with the 'kicker' and act normally for maybe a day or a week and then back to its random faults.
About the only things I haven't done are replace the self level relay or the valveblock driver.
Self level will be replaced as soon as I can get one delivered. I have Story Wilsons software but it is either corrupt or my laptop is so I can't access the AES computer to fault find or make any changes.

Now my knowledge of the system is pretty good and my engineering skills are very good but this has me stuffed.....it is looking like repair by replacement until I get it right.



Any suggestions would be appreciated, I have run out of hair.

[finallyrangie]

You could try replacing the timer relay with a standard yellow one, that should stop the computer getting involved overnight, might give you an idea if it's electrical or a more physical air problem, you might want to try downloading the eas software again, you might get lucky.

Good luck and keep us posted

[TheTree]

Hi

Check the OBD connector they are known to get a bit of corrosion in them. Clean it up and you will most likely be able to connect.

Secondly pull the EAS relay at night and see how it behaves, if it is OK then the problem is most likely the valve block driver

Steve

[Boblofty]

You could try replacing the timer relay with a standard yellow one, that should stop the computer getting involved overnight, might give you an idea if it's electrical or a more physical air problem, you might want to try downloading the eas software again, you might get lucky.

Good luck and keep us posted
Thanks' finallyrangie. That will be tonight's exercise. Just finished the valveblock rebuild late yesterday and left the vehicle stand with a full tank of air and measurements at the corners. Cold evenings here in Canberra but the losses after 3 hours were about 1/2cm at all corners and bugger all from the tank. Hoped I had solved the matter but thismorning it was down at the back and although it came up to height quickly, after golf it was back down again and although it came back up on the way home, as soon as the engine was turned off it settled to the stops chasing a level. arghhhh.
That (I hope) can only be the relay waking up after 5 hours in the dark and the whole system getting out of wack after that.
This is definitely an exercise in self control and leave the matches locked away.
I will get this solved. Cheers

[Boblofty]

Thanks' finallyrangie. That will be tonight's exercise. Just finished the valveblock rebuild late yesterday and left the vehicle stand with a full tank of air and measurements at the corners. Cold evenings here in Canberra but the losses after 3 hours were about 1/2cm at all corners and bugger all from the tank. Hoped I had solved the matter but thismorning it was down at the back and although it came up to height quickly, after golf it was back down again and although it came back up on the way home, as soon as the engine was turned off it settled to the stops chasing a level. arghhhh.
That (I hope) can only be the relay waking up after 5 hours in the dark and the whole system getting out of wack after that.
This is definitely an exercise in self control and leave the matches locked away.
I will get this solved. Cheers
Yeh thanks Steve. I considered that but the fact that the kicker works every time made me discount that as a possibility. However in the words of the immortal Khan...never assume anything. I will check

[TheTree]

If the kicker works every time I would be looking at the earth points around the EAS system and thinking the valve block driver may be dodgy. Does the epoxy in the driver look OK or is it crumbly ?

Steve

[Boblofty]

If the kicker works every time I would be looking at the earth points around the EAS system and thinking the valve block driver may be dodgy. Does the epoxy in the driver look OK or is it crumbly ?

Steve
Steve. You have inspired a new way to look at this problem. There is a common point to all of the system and that is the OBD port...if as you suggest there is corrosion and this is causing an intermittent earth, this could (possibly) trigger one or more of the suspension bag relays (or others for that matter) to operate in a random fashion.
I went out briefly tonight and after driving for some time with the right side down, I stopped briefly and when I started off again the bloody thing came up square and by the time I got home *about 10 mins) it was behaving itself.
In preparation for the electrics off test tonight, I replaced the standard relay with a 4 pin yellow and was standing by the gauge waiting for the tank to top up (I have fitted up a charge point and pressure gauge) and I noticed that the compressor seemed not to be charging the tank. It has just been rebuilt and so I pulled the silencer to check suction and it was sucking and therefore pumping so the air had to be going somewhere.
Turned the engine off to see if I could hear air escaping and one (and I don't know which one) of the relays went off clicking like mad (power should be off remember) and then stopped.
Obviously something is capable of feeding power to the valve block despite the system supposedly being electrically isolated.
In answer to your comment regarding earth points around the system, impossible to check everything of course but it is fair to say that the back of the drive looks like it has been mildly cooked or is just a dirty brown colour.
I have been a 'sparkey" for over 40 years and it doesn't smell cooked, just looks it.
Tomorrow I shall check the OBD for corrosion and seriously consider both a driver and relay second hand from Adelaide.
Thanks for all your responses thus far.
Cheers Bob

[daf11e]

Bob I have a spare driver here in Sydney if you'd like I can post it to you to try before you commit to buy.........just send me a PM


Jim

[Keithy P38]

I am helping an elderly gent up here in Townsville with the exact same issue you are having - to the word.

The only thing we haven't done is replace the driver unit or put it on coils. We've checked earths, checked for leaky air lines, replaced the valve block, replaced all air springs with new, traced wiring looms, etc. I've made an emergency bypass kit for him so he can set the P38 at his desired height and remove the delay relay to stop it moving in the event it plays up. It's a temporary fix, but allows him to pump up at the servo or using his own compressor if the gremlins creep in.

I cannot connect to his EAS ECU with my nanocom, but he has a kicker and Faultmate FCR that both communicate with the EAS ECU with no dramas.

His OBDII port is clean and corrosion free.

I will:

a) Follow this thread with much interest, and
b) Reply back with findings if we discover the problem.

As I said before, his P38 has the EXACT same issue you have. It's a '98 HSE.

Cheers for posting!
Keithy

[TheTree]

Hi

Apart from the under bonnet earths, which you would think are OK since the compressor runs, there is also the earth under the passenger seat.

Might be worth checking

Steve

[Boblofty]

I am helping an elderly gent up here in Townsville with the exact same issue you are having - to the word.

The only thing we haven't done is replace the driver unit or put it on coils. We've checked earths, checked for leaky air lines, replaced the valve block, replaced all air springs with new, traced wiring looms, etc. I've made an emergency bypass kit for him so he can set the P38 at his desired height and remove the delay relay to stop it moving in the event it plays up. It's a temporary fix, but allows him to pump up at the servo or using his own compressor if the gremlins creep in.

I cannot connect to his EAS ECU with my nanocom, but he has a kicker and Faultmate FCR that both communicate with the EAS ECU with no dramas.

His OBDII port is clean and corrosion free.

I will:

a) Follow this thread with much interest, and
b) Reply back with findings if we discover the problem.

As I said before, his P38 has the EXACT same issue you have. It's a '98 HSE.

Cheers for posting!
Keithy
Keithy. You have answered a fundamental human question. We are not alone...well at least I am not. If has happened to two P38's we are aware of, then there may be others.
Your input is valuable because it goes down the logical fault finding process as I am attempting to do.
Just for the record, mine was perfect before I was away overseas for 2 months in which time it sat on the stops..AND..the battery went completely flat. This may also be applicable to your "client". Worth asking the question as it may be a similar lead up.
I have to go away at the end of the week (only for a week) and although I am hopeful of a fix, I am expecting to have the fault when I go. In 3 weeks I will be in Qld and I have a mate there who is one of the best logical thinkers I know, also a previous P38 owner (we are discussing this problem) and I would bet my last buck he is working on it as we speak.
To all, I apologise for the length of some of my posts but my philosophy is the more you know the better the chance of success.
Keithy, watch this space and if you have anything else to add, please add it.
Cheers Bob

[Keithy P38]

Not a prob mate, enjoy the warmth up in QLD!

Cheers
Keithy

[ian4002000]

I am helping an elderly gent up here in Townsville with the exact same issue you are having - to the word.

The only thing we haven't done is replace the driver unit or put it on coils. We've checked earths, checked for leaky air lines, replaced the valve block, replaced all air springs with new, traced wiring looms, etc. I've made an emergency bypass kit for him so he can set the P38 at his desired height and remove the delay relay to stop it moving in the event it plays up. It's a temporary fix, but allows him to pump up at the servo or using his own compressor if the gremlins creep in.

I cannot connect to his EAS ECU with my nanocom, but he has a kicker and Faultmate FCR that both communicate with the EAS ECU with no dramas.

His OBDII port is clean and corrosion free.

I will:

a) Follow this thread with much interest, and
b) Reply back with findings if we discover the problem.

As I said before, his P38 has the EXACT same issue you have. It's a '98 HSE.

Cheers for posting!
Keithy


I changed the timer relay under the passenger seat in mine on the weekend and lost communication with the EAS on my nanocom, when I replaced the timer relay the nanacom worked again. What sort of relay have you got


Ian
Bittern Vic

[Boblofty]

I changed the timer relay under the passenger seat in mine on the weekend and lost communication with the EAS on my nanocom, when I replaced the timer relay the nanacom worked again. What sort of relay have you got


Ian
Bittern Vic
Ian. were you asking me or Keithy what model of relay I had. I don't know what he has but mine is a ANR 4652.

[Boblofty]

Here is some more info on the issue I have raised.
Last night I replaced the self level relay with a 4 pin yellow...theory says the valve block and driver is now electrically isolated unless ignition is on, air reservoir was left overnight with about 125psi.
This morning the vehicle was down at the back (but not all the way) and the air reservoir was low in pressure but had enough to bring the car up to height when I started the engine.
Went for a 15 minute drive, stopped checked the air pressure, it was down to about 65psi....so the compressor would appear to have not run.
Got back on the road (same 15 minutes) got home and checked the pressure, it virtually hadn't changed. Turned the vehicle off, charged the tank from my garage compressor and when the pressure hit about 100+ the bloody car went up to full off road height with no input from anywhere (that I am aware of). This should not happen.
So I let it down and waited till the compressor had cooled a little and started the car. Compressor is running but no change in tank pressure.....checked the compressor input and it was sucking, so something is letting the air out.
Turned the car off and just happened to be standing next to the valve block when I heard one of the relays click quite a few times and the tank pressure dropped a little. Valve block and driver are still electrically isolated No change in vehicle height.
My thoughts thus far are this.
As the self leveling is function is electrically isolated and the valve block should therefore do nothing....something has to be randomly triggering a valve response in the block. I suspect that triggering is releasing pressure from the tank and could well be triggering the air bags to release randomly which would explain why the tank is low overnight and there are random leveling problems. Keep in mind that the overnight problems do not always happen.
That said, after checking the electrical circuits in RAID, I have discovered that are a number of avenues that could supply power to the valve block other than the relay....AND IF....there is an earthing problem or a cooked circuit in the driver, this could trigger some sort of response.
I have a relay arriving tomorrow Tuesday, that will help isolate that area and Jim in Sydney has kindly offered to loan me a driver to check that aspect, that wont happen until Wed.

Keithy....most of this info is for you so that by Thursday I will have replaced just about all of the main components and depending on the results I have, all this may be of assistance to you.
Gotta say at the moment the driver (valve block driver that is...not me) is looking pretty guilty right now...damn I hope so.
All input/comments welcome.
Bob

[Keithy P38]

Thanks for that mate, I'll keep having a bo-peep over the week and see how you go.

The driver is the only thing we've not done at our end, so it's the next logical step for us too.

As for Ian's comment, the patient (P38 in question up here) is running a standard P38 delay timer relay.

By putting a yellow relay in under the passenger seat you will isolate (theoretically) all EAS activity with the ignition off. It will also prevent diagnostic communication with the EAS ECU (something to keep in mind).

Cheers
Keithy

[ian4002000]

After much fun with mine this week, it sounds like you have an air leak and the car is constantly using air to stay at the correct height.
I have found with mine that whilst it will not lose height or air pressure for two days it is still losing air whilst driven and the loss is worse at different heights.


A spray bottle and soapy water may be your best friend to chase leaks. I had to remove my valve block from the plastic box and then reconnect it to find one of the leaks on mine.
I found the air leak on the rear spring when the rear suspension is at full travel.


Good luck !


Ian

[Boblofty]

Thanks for that mate, I'll keep having a bo-peep over the week and see how you go.

The driver is the only thing we've not done at our end, so it's the next logical step for us too.

As for Ian's comment, the patient (P38 in question up here) is running a standard P38 delay timer relay.

By putting a yellow relay in under the passenger seat you will isolate (theoretically) all EAS activity with the ignition off. It will also prevent diagnostic communication with the EAS ECU (something to keep in mind).

Cheers
Keithy
Keithy. I have not had time to test the system on the road but here is the state of play. I replaced the driver with one loaned to me by Jim in Sydney. After fitting everything back up, I charged the tank from the garage compressor and the car came up normal and flat. This has happened on at least 4 occasions so I am fairly confident that I have solved the random height issues.
However (there is always a however), I have a problem with the compressor charging the tank and although I have double checked the return valves and the diaphragm solenoid, I have not yet solved this charging issue. Compressor is running and sucking but no charge coming through.
That aside for the moment, we are going away for a week tomorrow (road trip) so I intend to charge the system, lock the height, isolate the compressor (so it won't run continually) and carry a 150psi 12V compressor to charge the system if indeed I have to. That will see me through til' I get back.
But your interest lies in the results with the driver and I would say without a lengthy road test to prove it 100%, I have a fair degree of confidence that the driver was the underlying problem.
For info, I know that Triumph spares in South Oz have them second hand and new if you need one.
Over to you on that....sorry at this stage I can't give you a definitive answer.
Cheers Bob

[Boblofty]

After much fun with mine this week, it sounds like you have an air leak and the car is constantly using air to stay at the correct height.
I have found with mine that whilst it will not lose height or air pressure for two days it is still losing air whilst driven and the loss is worse at different heights.


A spray bottle and soapy water may be your best friend to chase leaks. I had to remove my valve block from the plastic box and then reconnect it to find one of the leaks on mine.
I found the air leak on the rear spring when the rear suspension is at full travel.


Good luck !


Ian
Thanks for the input Ian but no leaks that is a definite. See the post to Keithy on this page.
Cheers Bob

[Keithy P38]

Thanks mate.

I (along with old mate I'm helping out) have spare driver units, so will get to it when I get a chance. Sounds very promising!

I wish I could help more with your non-charging issue!

Cheers
Keithy

[Boblofty]

Thanks mate.

I (along with old mate I'm helping out) have spare driver units, so will get to it when I get a chance. Sounds very promising!

I wish I could help more with your non-charging issue!

Cheers
Keithy
G'day Keithy....solved the charging problem (valve block leak on a slightly deformed 'O' ring - faulty O ring not faulty workmanship). I am headed off to Victoria tomorrow for a week but having extensively road tested the vehicle this arvo I can say with a lot of confidence that the driver was the problem.
Particularly as when I solved the leak I ran the system up with the original driver...it came up high on the left side (same as one of the early faults). I dropped it down , swapped the driver out for the loaner from Jim and when I flashed up the vehicle, it behaved in a perfectly normal fashion on the garage floor and also on the test drive. (may have had something to do with the box of matches I had in my hand, but maybe not)
Anyhow all is good at the moment and I don't expect any issues on the trip.

Good luck with your driver change out.
Bob

[d2dave]

Bob, what part of Vic are you going to?

[daf11e]

Safe trip Bob"glad to help out"

Jim

[Boblofty]

Bob, what part of Vic are you going to?
Dave. We were up in the Ballarat area. Sorry I didn't get back to your question earlier but I had no access to emails or the site while I was up there.
Gotta say it was a great break but the weather was bloody awful especially for a golfer as I am.
Cheers Bob

[Boblofty]

Safe trip Bob"glad to help out"

Jim
Thanks Jim. For anyone who has been following this thread...For the first 2 nights the left wheel dropped about 5cm overnight other than that the suspension operated as it is supposed to. Third night in the entire system settled down and had performed flawlessly since.
There are 2 things from that.
1)

[Boblofty]

Thanks Jim. For anyone who has been following this thread...For the first 2 nights the left wheel dropped about 5cm overnight other than that the suspension operated as it is supposed to. Third night in the entire system settled down and had performed flawlessly since.
There are 2 things from that.
1)
Dunno what happened then but back to the thread at number 1 above.
1. I believe that the indents in the valve tips inside the block itself can be an issue particularly in an old vehicle because although the valve seat may be in good condition, the rubber tip can permanently 'dented' from years of sitting. Logically they would self center after dis-assembly given there is some clearance in the solenoid tube but I am not convinced that is necessarily going to happen overnight, it may take some operational cycles before it settles down.
2. For those who have a similar problem to the one that originally started this thread, I did replace the driver unit and things immediately came good in respect to the leveling problem.

Hopefully the matter is now resolved and I thank everyone for their input. Maybe this thread can help others along the way.
As a post script I have put away the matches until another time. The old truck is a delight to drive again.
And by the way, I have been on the road for a week since I resolved the problem (hence the time difference between posts) and about 2000kms later. That is a pretty good road test.
Cheers Bob