Xantia HA2 problem

bernie · Unread post by **bernie** » 06 Aug 2005, 15:53

Hi Simon
As you rightly say the led across the detached cable is void.
I have now successfully wired the led across the connected cable.

ON

OFF
As you say this eliminate the ecu side being fauly as the led does indeed work.
On a drive last night (easier to see the led)the led worked as you would expect, mostly on (soft mode).
Open door led on
Heavy braking, steering etc turned led off (hard mode).
Switching to sport mode gave an earlier response to body movement.ALL THE TIME THE RIDE WAS FIRM (hard mode)
So OK there then, ECU appears to work.
Problem must be further down the chain. BUT yesterday after running around with front HA cable disconnected ,I reconnected.
On opening the door the front dropped indicating the front HA sphere was at a lower pressure than the system (which would be correct) and therefor taking the excess oil into the sphere.
This points to the solenoid and the HA valve working.
We now come down to the HA sphere appearing to be flat.
BUT I have replaced all 8 (eight) spheres with new GSF items.
As has been said before I really need to pressure test them.
The rear HA valve behaves the same which prompted me to suspect the ECU in the beginning.
Could the HA spheres be flat? I relly need a good known sphere to test with, I may take the accumulater sphere off the BX to test.

Mandrake · Unread post by **Mandrake** » 06 Aug 2005, 16:23

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by bernie

Hi Simon
As you rightly say the led across the detached cable is void.
I have now successfully wired the led across the connected cable.

ON

OFF
As you say this eliminate the ecu side being fauly as the led does indeed work.
On a drive last night (easier to see the led)the led worked as you would expect, mostly on (soft mode).
Open door led on
Heavy braking, steering etc turned led off (hard mode).
Switching to sport mode gave an earlier response to body movement.ALL THE TIME THE RIDE WAS FIRM (hard mode)
So OK there then, ECU appears to work.
<hr height="1" noshade id="quote"></blockquote id="quote">
You've been busy [:)]
Looks like you have eliminated the ECU and sensors etc, which is good, because thats the one part of the hydractive system thats not really user servicable.. (if the computer snuffed it, replacing it would probably be the only choice, and some of the sensors are probably a real pain to replace too...)
By the way where did you manage to find a good place to join the wires in ? Even though today I've now proved both my electrovalves and the computer are working fine (see below) my curiosity still drives me to connect an LED somehow so I can watch the response of the computer to driving conditions [:D]
<blockquote id="quote">quote:<hr height="1" noshade id="quote">
Problem must be further down the chain. BUT yesterday after running around with front HA cable disconnected ,I reconnected.
On opening the door the front dropped indicating the front HA sphere was at a lower pressure than the system (which would be correct) and therefor taking the excess oil into the sphere.
This points to the solenoid and the HA valve working.
<hr height="1" noshade id="quote"></blockquote id="quote">
The FRONT valve working.... maybe the back one isn't ? I've now got the rear of my car working properly in soft mode, and its made a HUGE difference to the overall ride quality even though the front still needs the corner spheres replacing.
<blockquote id="quote">quote:<hr height="1" noshade id="quote">
We now come down to the HA sphere appearing to be flat.
BUT I have replaced all 8 (eight) spheres with new GSF items.
As has been said before I really need to pressure test them.
<hr height="1" noshade id="quote"></blockquote id="quote">
If you have a pressure tester already, then that would be worth trying, yes.
<blockquote id="quote">quote:<hr height="1" noshade id="quote">
The rear HA valve behaves the same which prompted me to suspect the ECU in the beginning.
<hr height="1" noshade id="quote"></blockquote id="quote">
Oh, wait, do you mean the back will sometimes drop when a door is opened ?
<blockquote id="quote">quote:<hr height="1" noshade id="quote">
Could the HA spheres be flat? I relly need a good known sphere to test with, I may take the accumulater sphere off the BX to test.
<hr height="1" noshade id="quote"></blockquote id="quote">
Excellent idea - and thats exactly what I did earlier today.
I'd ordered a new accumulator sphere (since it needs replacing too) but thought why not try it temporarily as a rear hydractive centre sphere before fitting it on the regulator to find out for sure if centre sphere is the reason why the rear was always in hard mode, and BINGO, soft mode is now super soft.
In fact because the acculator sphere is 62 bars instead of the correct 50 bars, its about 25% too soft, so the rear suspension is somewhat lively in the soft mode [:D] Even so it is quite drivable, the only annoying side effect being a bit much squat on acceleration, and possibly a *wee* bit of float.
So if you have a known good accumulator sphere to do a test, DO IT.
The difference between soft and hard mode is so obvious you can tell with a simple bounce test whether the centre sphere is working - the easiest way to do it is to pull the fuse out for the HA computer to test hard mode, and put it back in for soft mode, with the engine running the whole time.
Turning the engine off and closing the doors for 30 seconds to get hard mode isn't quite as conclusive because when you open a door for soft mode, if there isn't enough pressure left in the main accumulator the hydractive plunger wont actually move to soft mode even if the electrovalve is energized - making you think the soft mode isn't working.
So to ensure it really does switch the plunger into soft mode the engine must be running to keep the accumulator topped up, but with the engine running it will not switch to hard mode even with the doors closed - hence the fuse pull approach.
(Another slower method would be to run the engine with the doors closed for soft mode, then turn the engine off through the window and wait 30 seconds for hard mode, then turn the engine on again for soft mode)
You could also try your test accumulator sphere in place of the front hydractive sphere as well - but this time the soft mode will be about 25% stiffer than it should be (the normal pressure for that sphere is 70 or 75 bars depending on the cc size) but there should still be a fairly obvious difference between the soft and hard mode on a bounce test.
Good luck [:)] Maybe you're just unlucky and have a couple of DOA centre spheres...
Regards,
Simon

bernie · Unread post by **bernie** » 06 Aug 2005, 17:01

Hi Simon yes the back does drop also.
Your right about expecting soft mode when door is opened and engine off, there may not be enough pressure.
I was about to take the acc. sphere off the BX and it started to rain!!!!!!!!!!!
I've spliced into the front circuit after removing the black plastic box containing the HA and engine ECU's.
It's fairly dry under there.
I've then run the cables past the windscreen and through the door opening. (temporary job?????????)
It's dangerous driving though watching the green led flash whilst trying to turn it off, HA HA

Mandrake · Unread post by **Mandrake** » 06 Aug 2005, 18:36

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by bernie

Hi Simon yes the back does drop also.
Your right about expecting soft mode when door is opened and engine off, there may not be enough pressure.
I was about to take the acc. sphere off the BX and it started to rain!!!!!!!!!!!
<hr height="1" noshade id="quote"></blockquote id="quote">
I thought it was supposed to be summer over there !! [:D]
The rain threatened all day here today but I got fed up waiting and just did it, and as it happened, it didnt rain, amazing considering its the middle of winter here...I'm sure the weather acts out of spite sometimes, it always seems to pick when you're right in the middle of a job, regardless of what time you start on it...[:(!]
<blockquote id="quote">quote:<hr height="1" noshade id="quote">
I've spliced into the front circuit after removing the black plastic box containing the HA and engine ECU's.
It's fairly dry under there.
I've then run the cables past the windscreen and through the door opening. (temporary job?????????)
<hr height="1" noshade id="quote"></blockquote id="quote">
Ok, I'll have a look in there then.
I was thinking of perhaps mounting the LED properly in the bottom of the plastic frame that holds the radio - out of sight when the radio drawer is shut, and perhaps put a tiny pushbuton next to it to disable it when not needed to avoid glare. (Yes I know I'm strange installing a light like this, but I like gadgets [:D])
<blockquote id="quote">quote:<hr height="1" noshade id="quote">
It's dangerous driving though watching the green led flash whilst trying to turn it off, HA HA
<hr height="1" noshade id="quote"></blockquote id="quote">
I bet. Probably nearly as dangerous as looking down at the light on the Normal/Sport switch. (Why DID they put it there ?????)
It's a deathtrap fiddling with that switch while driving unless you have a long straight clear piece of road ahead of you before looking down...if only you could tell if the switch was up or down by feel without having to look down.....
Regards,
Simon

bernie · Unread post by **bernie** » 09 Aug 2005, 01:50

I did not take the accu. sphere off the BX because the AIR CONDITIONING pipes got in the way.
I did however move the recent accu. sphere on the Xantia to the rear hydra. position and fitted the original accu.sphere in it's place.
Result much better ride.
It would seem that the new hydra. spheres I bought from our host are U/S.
The sphere I removed was marked 62 bar, is this right for the rear hydra. 1999 HDi estate?

Mandrake · Unread post by **Mandrake** » 09 Aug 2005, 02:16

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by bernie

I did not take the accu. sphere off the BX because the AIR CONDITIONING pipes got in the way.
I did however move the recent accu. sphere on the Xantia to the rear hydra. position and fitted the original accu.sphere in it's place.
Result much better ride.
It would seem that the new hydra. spheres I bought from our host are U/S.
The sphere I removed was marked 62 bar, is this right for the rear hydra. 1999 HDi estate?
<hr height="1" noshade id="quote"></blockquote id="quote">
No, it should be 50 bars.
I've still got a 62 bar accumulator sphere on the rear hydractive centre for the moment, (until the proper one arrives) and its too soft. Soft as a marshmellow in fact [:D] And a bit floaty...very soft ride though.
It's approximately 25% too soft compared to normal, so bear in mind that even if the original sphere was ok, it would be a bit softer with the accumulator sphere in place.
So did you do a bounce test at the back in both soft and hard mode before and after the sphere changearound ? Was it about the same stiffness in hard and soft mode before the change, (eg quite stiff) and now a lot softer in soft mode for the bounce test ? As I say, the difference between soft and hard mode is VERY obvious with a bounce test with the accumulator on there...
If so that definately fingers that sphere as being faulty...
Also, are you saying that the sphere that had been originally supplied to you as the rear hydractive centre says 62 bars on it ?
If so, it was an accumulator sphere, which means it was either too high in pressure, or had been regassed to 50 bars, or maybe was second hand and left to drop to 50 bars by its own accord [|)]
Possibly a common trick for a regassed/reconditioned sphere, as the spheres are basically identical apart from the pressure. (Although I've seen pictures on the net that show a slightly different neck design for the HA sphere, the one I took off my car which was a genuine one, has EXACTLY the same neck design as the accumulator...)
However, if you bought it as "new" and got a sphere marked 62 instead of 50, you'd have to wonder a bit...and I would be querying that. Perhaps it was a mixup in packaging or labeling...
Regards,
Simon

bernie · Unread post by **bernie** » 11 Aug 2005, 00:49

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Mandrake

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by bernie
I am in total agreement Mandrake.
I think a good idea would be to pool all our resources, testing and results etc.
We should be able to crack this between us.
<hr height="1" noshade id="quote"></blockquote id="quote">
One thing that I notice the Hydractive system on my car is doing that doesn't tally with expectation based on theory is this little test that I concocted:
1) Lift the car height right up, all doors closed, (so as not to trigger the open door switch which sends a signal to the computer) drivers window right down, then turn off the key, and wait for the 30 second timeout for the solenoids to drop out back to hard mode. (Audible click, and whining noise stops)
2) Then immediately lower the height lever to normal WITHOUT opening the door. The car should go down to normal height, but we have trapped the full 170 bar regulator pressure in the hydractive spheres.
3) Finally, key still off, open the drivers door. As soon as the solenoids switch on, there SHOULD be a sudden jump in height of the car, as the excess pressure out of the hydractive sphere is dumped back into the main suspension spheres, but on my car it DOES NOT. I can clearly hear the solenoids whining continuously when I open the door, but there is no jump.
However, when I turn the key on and start the motor, about 2 seconds later both front and back will suddenly jump up about 3 inches, (then correct back down to normal height) which is what I was expecting by simply opening the door.
My conclusion from this is that despite the solenoids being energized, the hydractive blocks are not actually being switched back into soft mode. The only reason I can think of this being the case is that there is not enough main pressure regulator pressure left to move the hydractive control valve despite the solenoid being activated.
To add some weight to this theory, I DO suspect the accumulator sphere is nearly dead on this car - it fails to do a sit in the boot lift test, and yet there is no audible rapid cycling of the regulator cutout noise...until I get a chance to do some more testing, or do a pressure test on the accumulator sphere, I won't know for sure, but I'm now suspecting that a bad accumulator sphere could upset the switching of the hydractive valves, at least when the engine is off anyway...
How much significance this might have to hard/soft switching while the engine is running (if any) is unknown however...perhaps at worst it will just slow down the hard to soft transition time...
Anyone got any ideas ? Anyone else care to try my test and see if the car jumps when the door is opened, as I think it should ? Or does it only jump after starting the engine ? (Implying not enough regulator pressure to open the anti-sink valves and/or operate the hydractive control valves..)
More info as I figure it out...
Regards
Simon
<hr height="1" noshade id="quote"></blockquote id="quote">
Update
Suspension was better with accu. sphere on the back but not right[:(]
I've done the hard/soft test and it was nice and soft at the back in soft mode and hard in sport mode.
However when I switched back to soft the rear was hard again!!!!!!!!!!!!
So there's still something up.[}:)]
Simon I've just performed your test, as instructed, and the front and back leapt up when the door opened.

JohnCKL · Unread post by **JohnCKL** » 15 Aug 2005, 22:37

Sent my car for HA2 ECU testing on Proxia computer. There were 5 problems diagnosed but not sure all are from my car as the ECU was a used unit. Steering wheel angle sensor out, accelerator pedal incorrectly adjusted, electrovalve 2 out, speed sensor out and problem calculating straight ahead. Looks like there are too many sensors which can go wrong.

Mandrake · Unread post by **Mandrake** » 16 Aug 2005, 07:16

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by JohnCKL

Sent my car for HA2 ECU testing on Proxia computer. There were 5 problems diagnosed but not sure all are from my car as the ECU was a used unit. Steering wheel angle sensor out, accelerator pedal incorrectly adjusted, electrovalve 2 out, speed sensor out and problem calculating straight ahead. Looks like there are too many sensors which can go wrong.
<hr height="1" noshade id="quote"></blockquote id="quote">
Hi John,
I'm curious to know how the ECU "knows" some of these things.
For example how can the steering wheel angle sensor be "out", as it is an optical chopper disk which doesn't have a centre alignment - it can go around and around. Its the job of the ECU to figure out what the straight ahead position is based on a set of heuristics.
(I won't go into them here but its covered in the very good Citroen technical guide linked from this site)
Also how can it know electrovalve 2 is out when they are both connected directly in parallel ?
All these faults seem a bit unlikely to me, perhaps these faults were recorded in the old car, or perhaps the unit was powered up with no sensors connected and decided they were all faulty ?
Maybe worth resetting all the errors and driving it for a couple of weeks and checking again to make sure you're not chasing red herrings...[:D]
Or perhaps test it yourself by doing bernies LED test and observing the response to various driving stimulus. Just because a fault code has been logged in the dim dark past (possibly on the original car) doesn't mean it might not be working fine now...
Regards,
Simon

JohnCKL · Unread post by **JohnCKL** » 16 Aug 2005, 08:51

Hi Simon, you're right, it could have been the original car's faults recorded. However I did adjust the accelerator pedal before, so that's probably true. I've taken the whole steering wheel and sensor out previously but that was adjusted to the right angle with my original ECU the last time before changing to the used ECU, so maybe that's not correct. That's the trouble of swapping used ECU when its previous diagnosis were not erased. Realised that later after the test. Yup, got to send it back for retesting to confirm the actual problems now that all of the previous faults were erased. I believe the ECU gets continuous feedback from all the related sensors for its calculations on suspension. Getting more complex!

zzf00l · Unread post by **zzf00l** » 16 Aug 2005, 12:15

Doesn't the ECU re-set when battery is disconnected???
Ian

JohnCKL · Unread post by **JohnCKL** » 18 Aug 2005, 08:54

Ian, you're right, the ECU does re-set itself if disconnected from the battery for at least half an hour, that's what my mechanic told me. In that case, those diagnosed faults are surely from my car as the used ECU was removed and stored for quite some time. Seems that Hydractive2 cars need to have the Proxia diagnosis if we are to remove or adjust the sensors in the steering wheel, accelerator pedal and god knows what else. If electronics continue to fail, then maybe need to convert suspension down to the basics only.