Xantia HA2 problem

bernie · Post by **bernie** » 27 Jul 2005, 01:08

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

HA2 Speed sensor ?
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Could be.
Anyone know the test for a speed sensor?

Mandrake · Post by **Mandrake** » 27 Jul 2005, 03:56

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

I'll try on mine Simon.
One thing I've noticed on mine is the lhm feed to the rear solenoid is just drips.
I believe it's feed from the security valve if I can find it.
Yesterday I swopped the rear HA sphere for another.
I then started it up and it pumped to max. height, I opened the door and immediatly sunk to the floor. Now the door obviously operated the solenoid that opened the ha block and the ha sphere took all the pressure from the rear.
BUT I could hear the solenoids when I turned on the ignition so surely the ha sphere should have been filling also. Very strange.
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Yes,
This is exactly the kind of strange things I'm noticing - solenoids supposedly being activated, based on the noise they make, and yet centre sphere still isolated. Perhaps not enough power to reliably operate them due to an earthing fault or similar ?
A solenoid is basically like a relay without relay contacts, and with any relay there is a minimum current threshold below which they will not activate. If the physical movement of the plunger is not as smooth and easy as it should be due to build up of rust/gunge/whatever, and/or there is not quite enough power operating it it is quite possible that it may not engage the soft mode properly...
As soon as you start the engine when the car is stationary, it should be in soft mode, it shouldn't need the door opening. Which gives me a thought - perhaps in your case the signal from the ignition switch to the HA2 computer is not working ?
That could explain why you could start the car and pressurize it seemingly without the HA sphere being activated, yet opening the door then allows the HA sphere to become active.
In fact the more I think about it, if the ingition key signal to the computer is missing, the only time your car will ever be in soft is when the doors are open, and it will be in hard during all normal driving, because the computer thinks the ignition is turned off and therefore you can't be going anywhere [:D]
It could be as "simple" as a faulty ignition switch or wiring...
The approach of wiring up an LED and resistor to the solenoid control voltage would prove this for sure one way or the other - perhaps whats happening is that when you open the door to get in the car the door switches activate the soft mode (you hear the solenoids trigger) then you shut the door and start the engine.
Once the engine is running there is too much noise to tell if the solenoids REMAIN active. If the computer thinks the ignition key is off all the time, 30 seconds after you close the doors the car will go back into hard mode and stay there even though the key is on and you are trying to drive...sound like what might be happening to you ?
Does anyone know of an online copy of the pinouts of the Hydractive 2 computer ? One that shows what goes to the ignition switch, sensors, solenoids etc ? If I could get my hands on that I could diagnose it 10 times faster...
Regards,
Simon

Mandrake · Post by **Mandrake** » 27 Jul 2005, 04:13

<blockquote id="quote">quote:<hr height="1" noshade id="quote">
It could be as "simple" as a faulty ignition switch or wiring...
The approach of wiring up an LED and resistor to the solenoid control voltage would prove this for sure one way or the other - perhaps whats happening is that when you open the door to get in the car the door switches activate the soft mode (you hear the solenoids trigger) then you shut the door and start the engine.
Once the engine is running there is too much noise to tell if the solenoids REMAIN active. If the computer thinks the ignition key is off all the time, 30 seconds after you close the doors the car will go back into hard mode and stay there even though the key is on and you are trying to drive...sound like what might be happening to you ?
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Ok, I just did a little test on mine which I think proves that my ignition switch to HA2 computer signal is working ok, so you could try this test too:
Park your car in a small garage (makes the solenoid whine MUCH easier to hear) with the drivers window down and the doors closed, verify that opening the door then closing it allows the solenoids to run for about 30 seconds then cut off,
Then without opening the door, turn the ignition key on without starting the motor and see if the solenoids come on and STAY ON for as long as you leave the key on. Try leaving the key on a few minutes and make sure the solenoids stay on.
After turning the key off (door still closed) the solenoids should stay on for 30 seconds, then turn off.
Let me know the result...
Regards,
Simon

ActivaV6uk · Post by **ActivaV6uk** » 27 Jul 2005, 04:42

speed sensor - hall effect, is 8 impulses per revolution - 5 impulses per meter.
its a 12v sensor so you are going to have to let the car role forwards and intersept the sensors output (wire number 1620) (check this for a constant short or an intermitant fault).
the stearing sensor can be ruled out as it only comes into use after you hit 30MPH
there is one other thing that being the body movement sensor which is located on the fornt subframe to the right of the front hight corrector. this is an opto electric device if you give it a 12v suple it should generate an impulse every time the arb moves and there are 45 teathe so its pretty sensitive. i would check this first as it says in the manual that even a slight movement when parked will make it switch form hard to soft. (wire number 7705).
best wishes
Andy

Mandrake · Post by **Mandrake** » 27 Jul 2005, 04:52

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by ActivaV6uk
there is one other thing that being the body movement sensor which is located on the fornt subframe to the right of the front hight corrector. this is an opto electric device if you give it a 12v suple it should generate an impulse every time the arb moves and there are 45 teathe so its pretty sensitive. i would check this first as it says in the manual that even a slight movement when parked will make it switch form hard to soft. (wire number 7705).
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What manual is this ? Owners manual or a service manual ? I see no mention of that in my owners manual. Also bouncing the car up and down while parked and turned off in hard mode doesn't trigger the solenoids on, and I can't see why it would want to either...as it would be coming on every time the suspension sunk a bit and help run the battery flat...
Now you've got us confused [:D]
Regards,
Simon

ActivaV6uk · Post by **ActivaV6uk** » 27 Jul 2005, 06:20

<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 ActivaV6uk
there is one other thing that being the body movement sensor which is located on the fornt subframe to the right of the front hight corrector. this is an opto electric device if you give it a 12v suple it should generate an impulse every time the arb moves and there are 45 teathe so its pretty sensitive. i would check this first as it says in the manual that even a slight movement when parked will make it switch form hard to soft. (wire number 7705).
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What manual is this ? Owners manual or a service manual ? I see no mention of that in my owners manual. Also bouncing the car up and down while parked and turned off in hard mode doesn't trigger the solenoids on, and I can't see why it would want to either...as it would be coming on every time the suspension sunk a bit and help run the battery flat...
Now you've got us confused [:D]
Regards,
Simon
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official citroen workshop manual.
It shows how much info you can get from just listening... i'd recomend testing all the sensors properly ive just found the section with the sensor values in it i will post them some time tomorrow.
Also the EV being turned on when the car sinks is mentioned and the power requirements for teh EV are so low that the batery would out last the suplie of fluid in the antisink systems and the main accumulater put together.
Andy

pete_wood_uk · Post by **pete_wood_uk** » 27 Jul 2005, 13:56

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

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..)
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I haven't run outside specifically to do this test, but as far as I recall from washing my car, my HA2 stays up at full height with the engine off but with the height control moved back to normal. It's always puzzled me, the non-HA2 car behaves as you'd expect - move the lever, short pause, down we go - but the HA2 just seems stuck til the engine starts. As far as I know there's not a lot wrong with the accumulator on that car (as opposed to the non-HA car whose spheres are shot) - when I had those brake problems a couple of months ago it took me ages to exhaust the accumulator pressure.
I appreciate that this probably does help much [:)]
Pete

Mandrake · Post by **Mandrake** » 27 Jul 2005, 15:02

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

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

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..)
<hr height="1" noshade id="quote"></blockquote id="quote">
I haven't run outside specifically to do this test, but as far as I recall from washing my car, my HA2 stays up at full height with the engine off but with the height control moved back to normal. It's always puzzled me, the non-HA2 car behaves as you'd expect - move the lever, short pause, down we go - but the HA2 just seems stuck til the engine starts. As far as I know there's not a lot wrong with the accumulator on that car (as opposed to the non-HA car whose spheres are shot) - when I had those brake problems a couple of months ago it took me ages to exhaust the accumulator pressure.
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Hi Pete,
The only thing that can stop the height comming down when the lever is set back down to normal is the anti-sink valves. Because the valves work on differential pressure not absolute, at normal height they will only close when the regulator pressure drops below the normal suspension pressure, so it will take them some time to close.
However when you have the car at full height, there is not much pressure difference between both sides of the anti-sink valve, so it doesn't take much drop in pressure at the regulator for the valves to close thus locking the car at full height.
Add to this the fact that in my experiments so far I've found that it takes a significant amount of oil supply from the main accumulator to switch the plunger in the hydractive blocks from hard to soft mode - which happens every time you open a door that has been closed for more than 30 seconds, so if you're opening and closing doors you could easily use up some of the regulator pressure just by doing that, then end up causing the anti-sink valves to close.
Thats my theory anyway [:D]
Regards,
Simon

Mandrake · Post by **Mandrake** » 27 Jul 2005, 15:10

Ok to all those following this thread, I think I've established with pretty good certainty that the regulator sphere and front corner spheres on my car are nearly flat.
The regulator sphere by the sit in the boot test (and a few other common symptoms) and the front spheres by basically unplugging the feed to the front hydractive solenoid and allowing the car to run, forcing the front into the hard mode - in this condition the damping should be very slow/firm, but it should still go down a couple of inches or more when sitting on the front.
As it is now, with two people sitting on the front, it goes down only about half an inch in fact pushing it up and down as hard as I can it wont travel more than about this, so I suspect there is extremely low gas in the front corner spheres.
The front hydractive sphere whilst maybe not perfect is making quite a considerable difference - when reconnecting the solenoid to enable soft mode the front now goes down about 2-3 inches when I sit on it, about the same amount as a normal Xantia, so I think that sphere is good enough for now...(at least until I get my pressure tester rebuilt)
At the back the story seems to be the opposite - it looks like the rear hydractive sphere is dud, but the corner spheres are ok, or at least okish enough to leave them in until I can properly pressure test them.
Connecting or disconnecting the solenoid seems to make virtually no difference to the softness or feel at the back - in both cases it goes down a couple of inches or more when I sit on it, and in both cases the damping is very slow especially in the rebound, so its either a dud hydractive sphere or the solenoid. (My guess is the sphere)
Based on that I've ordered a new Accumulator, front corner spheres, and rear hydractive sphere, so we'll see how things are going after replacing those....
As far as I can tell the hydractive computer is working fine, but I'll know a bit better once the new spheres are on...
Regards,
Simon

Kered · Post by **Kered** » 28 Jul 2005, 03:03

This takes me back to around 4-5 years ago. At that time I had a 1.9TD VSX. The suspension at the front became rigid. As this was, to me, pre GSF I obtained 2 new spheres from Citroen. It made no difference so I booked it in for a computer diagnostic job. It turned out that a fuse was missing! This was a mystery to me as I was the only driver from new and it had worked fine EXCEPT:- the hard mode light never ever came on unless the side / main lights were on first. This turns out to be a diagnostic indicator. Does your hard / soft mode switch light up without sidelights?
Derek

Mandrake · Post by **Mandrake** » 28 Jul 2005, 03:19

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

This takes me back to around 4-5 years ago. At that time I had a 1.9TD VSX. The suspension at the front became rigid. As this was, to me, pre GSF I obtained 2 new spheres from Citroen. It made no difference so I booked it in for a computer diagnostic job. It turned out that a fuse was missing! This was a mystery to me as I was the only driver from new and it had worked fine EXCEPT:- the hard mode light never ever came on unless the side / main lights were on first. This turns out to be a diagnostic indicator. Does your hard / soft mode switch light up without sidelights?
Derek
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Yes, the sport mode LED on the button does light up, without headlights on. When I first got it I think the switch was a bit dirty as I couldn't get it to come on, but after working it on and off a few times it now seems to switch on and off reliably.
When the headlights are on I find it quite hard to tell whether the sport mode LED is on or not, the difference in brightness is not very obvious.
IMHO the button is poorly placed and I could see how someone could easily run off the road looking down and fiddling with that switch while driving [:D]
Which spheres did you replace that made no difference ? Hydractive ones (which wouldn't have made any difference if the computer was disabled) or corner spheres ?
I've already established that my computer is running ok and putting the solenoids into soft mode...
If your sport mode light never worked (without headlights on) then it sounds like your hydractive computer was missing its fuse from day one [:0]
In that case your car would have been permanently in "hard" mode, and when it became rigid was when the corner spheres finally died.
However the "hard" mode is probably not as hard as many conventionaly sprung cars so you may not have realised unless you had a drive in another VSX to compare it against...
Does it ride better now that its all fixed than it did when it was new ?
Regards,
Simon

ActivaV6uk · Post by **ActivaV6uk** » 28 Jul 2005, 15:17

Kered your issue seems like a pretty common one but i'm guessing that the fuse is blowing rather than being removed, you dont by chance know waht number the fues was?
The switch is an interesting device as it uses a bulb with a plastic cover in it, if your light ever goes white then the plastic burnt through and fell apart due to the heat of the bulb.
Andy

Kered · Post by **Kered** » 28 Jul 2005, 19:59

The spheres I changed were the 2 fronts on the suspension struts. On fitting the new ones and finding no difference I got them to check it over. They couldn't communicate with the suspension computer and that led them to finding no fuse fitted - but I don't know which one. On fitting it it worked fine and for the first time the mode light actually worked. The ride was then back to how it was!
What I can't understand is that the suspension worked fine - in both modes. My favourite trick was to go round roundabouts in sport mode and halfway round swith to normal. The car would lurch into a roll from its previously flat cornering and it always impressed the passengers (except the wife!)
I also can't fathom why is suddenly went rock hard!
Anyway I'm on an HDi 110 Estate SX now so I'm no longer HA.
Derek

bernie · Post by **bernie** » 05 Aug 2005, 18:46

Right then back to the problem.
I've disconnected the cable from the front HA valve, taken it for a test drive and it's the same as connected. Hard mode.
I've bought some 12v leds.
I fitted one into the front ha cable and all I get is a flash every 30 seconds proving the polling works. (equalise pressure between HA sphere and system)
Question. Is this a fair test or does the cable plug have to be connected with led across legs?

Mandrake · Post by **Mandrake** » 06 Aug 2005, 03:54

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

Right then back to the problem.
I've disconnected the cable from the front HA valve, taken it for a test drive and it's the same as connected. Hard mode.
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Ok thats good... another slightly more conclusive way you can do the test is to simply pull the fuse out for the HA computer. (The right fuse is listed in the manual)
Also try doing a stationary bounce test at the front and back in this fuse out condition to confirm that it doesn't seem any harder than before. (Implying its always in hard mode)
If you can notice no difference at all in the ride with the cable disconnected or fuse removed then that narrows it down to either hydractive centre spheres, (if they're completely punctured there will be no difference between hard and soft) or the electovalve or the control signal.
Currently on my car when I do the fuse out test there is no change at the back, but the front goes from moderately firm to VERY hard. (My rear hydractive centre sphere is faulty, which I will be confirming today by temporarily putting a spare accumulator sphere on it, and my front main corner spheres are nearly flat)
<blockquote id="quote">quote:<hr height="1" noshade id="quote">
I've bought some 12v leds.
I fitted one into the front ha cable and all I get is a flash every 30 seconds proving the polling works. (equalise pressure between HA sphere and system)
Question. Is this a fair test or does the cable plug have to be connected with led across legs?
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If you connected the LED's while the front solenoid is *disconnected* you've voided the test, the reason being that the computer senses the current draw is less than that of two solenoids and assumes a fault condition.
In this fault condition the computer will pulse it once every 30 seconds to see if the fault has cleared. (This is not the same as the once per minute pressure equalization pulse that only occurs during hard mode)
The reason for this design I suspect is to ensure that if a wire dropped off ONE of the electovalves, that the computer doesn't energize the other one, so that BOTH ends of the car stay in hard mode.
Having one end of the car switching from hard to soft while the other end always stays hard could potentially be an unsafe handling condition so I can see why they did it.
So you really need to devise a way to connect the LED while both electovalves are still connected.
On my car if I park it and turn it off then open a door I hear a distinct 'click' as both electovalves come on, then a continuous high pitched whine, showing that the electovalves are energized. However if I unplug the front electovalve and do the same test I get a double click (on then off) and silence for 30 seconds or more..then another double click, which is what you're talking about.
If you can somehow rig your LED to be connected while the solenoids are connected and confirm that the light is on in situations where you expect the car to be in soft mode, then that eliminates the computer control signal as a source of trouble and brings you back to only the centre spheres or the electovalve assembly.
Regards,
Simon