New Spheres Xantia V6

f00lzz · Post by **f00lzz** » 05 May 2008, 21:03

An update.

I have spent a little time this weekend doing extensive Citrobotics, checking tyre pressure etc and generally messing about. It would now appear that for Sport/Hard mode read 'Kangaroo mode'. I found that if I manually select Sport/Hard mode this puts the car into permanent Kangaroo mode which perhaps explains why when in normal mode it only seems to 'Kangaroo' when turning/braking.. isn,t this when the suspension changes to sport/hard mode automatically?? Perhaps someone with a better understanding of what each of the eight spheres on my car does can shed some light! and do you think that one of the spheres may be 'flat' ???

Post by **CitroJim** » 05 May 2008, 21:33

In soft mode Ian, the corner spheres are almost effectvely out of action and suspension is largely determined by the hydractive centre spheres. In hard mode, the Hydractive centre spheres are switched out of circuit and all suspension relies on the corner spheres.

Flat corner spheres may be the cause although Hydractive corner spheres are hard by design and in tests on a good working Hydractive system, the car switches to hard mode very rarely. Yours seems to be switching to hard mode far too readily.

You may have a problem in the Hydractive electronics. All operating the normal/sport switch should do is change the thresholds of when the system switches from soft to hard. It should not render the soft mode completely inoperative; it did with the Hydractive I system on early XMs but all Xantias have Hydractive II which specifically overcomes this limitation.

The first thing I'd be tempted to do is have a full electronic disgnostics session on the Hydractive system. Trouble is, you need to find someone with the proper kit and a knowledge to read and understand what it is telling them.

On Xantia series 1 Hydractive systems there is a brake pressure switch under the LHM reservoir that detects heavy braking and tells the Hydractive ECU to switch to hard mode under such conditions. This switch is known to suffer dirty connections which can fool the ECU into thinking you are always braking heavily and thus keeps the suspension in hard mode. The other sensors in the system are a throttle sensor which causes the ECU to switch to hard mode if you accellerate sharply, a steering angle sensor to detect how much steering input is going in and finally a yaw sensor attached to the front anti-roll bar to measure roll and pitching. Any sensor failing or giving bad information will be discounted from the ECUs calculations and default values will be used. The steering angle sensor often causes an intermittent fault to be logged in the ECU and clearing it seems to improve matters; as do any stored Hydractive faults.

A diagnostic tool should locate your problem very quickly. To find the duff part without will be a nightmare and even if you do find it, without clearing the fault codes from the ECU, you may not know you've found it.

Reminds me, I must investigate why my Activa frequently throws up an intermittent steering angle sensor fault.

Finally, it is possible the hydraulics themselves are faulty. Although the ECU might be sending the electrovales the right signals, the electrovalves may not be doing what they should because of low hydraulic pressure. How's your regulator tick rate? If it is fast then your accumulator shpere may be flat and this will have a detrimental effect on every aspect of suspension function. In a Hydractive car, the tick rate should be very long. Also, hydractive electrovales can leak in soft mode and cause a fast tick rate and low pressure. There have been threads about this in the past on here. Look for posts by Mandrake (Simon). In fact, I expect Simon will be along soon to give his thoughts on your problem. He knows more about Citroen hydraulics than all the rest of us put together...

DickieG · Post by **DickieG** » 05 May 2008, 21:34

f00lzz wrote:I have spent a little time this weekend doing extensive Citrobotics, checking tyre pressure etc and generally messing about. It would now appear that for Sport/Hard mode read 'Kangaroo mode'. I found that if I manually select Sport/Hard mode this puts the car into permanent Kangaroo mode which perhaps explains why when in normal mode it only seems to 'Kangaroo' when turning/braking.. isn,t this when the suspension changes to sport/hard mode automatically?? Perhaps someone with a better understanding of what each of the eight spheres on my car does can shed some light! and do you think that one of the spheres may be 'flat' ???

Turning on sport mode only narrows the perameters at which the suspension switches to firm mode, if you are driving in a straight line at a constant speed then turn the steering quickly/apply release the accelerator quickly, the suspension will switch to firm quicker/sooner in firm mode but it will still switch to firm in soft mode if the movement is sufficiently sharp.

Before any further diagnosis can be achieved over a forum have you tried 'listening' to the suspension over the radio (171 LW)? If it is switching OK then you more than likely have flat centre sphere's.

f00lzz · Post by **f00lzz** » 05 May 2008, 22:02

Thanks both... it almost makes sense to me now

Glad I'm calling in at eurocare in the morning £25 for a diagnostic,, keeping my fingers crossed.

f00lzz · Post by **f00lzz** » 06 May 2008, 17:07

Eurocarcare Diagnosis:

One or both front corner spheres flat.. so much for new spheres fitted!

Apparently I have eight 're-filled' spheres which have replaced better quality multilayer spheres which may not have had anything wrong with them..

Anyway.. Have just bought two new front corner spheres from Eurocarcare.. see how it goes, if still no good replace the rear corner spheres.

Needless to say I am 'a little dissapointed' that I am changing spheres so soon and if I could be bothered with a drive up to Manchester!!!!!

More importantly at the moment:

Two spheres, both marked XA 45 FL 31-10-07 hope these are correct ones.

I have 'cracked' the joint on both old spheres.. suspension is at the lowest setting.. please tell me that I don't have to locate and slacken that pressure release screw, it would be a nightmare!!

Stempy · Post by **Stempy** » 06 May 2008, 18:08

I think you really ought to release the pressure, other wise you might end up with an engine bay flooded with LHM. It's not that hard to get at with a long spanner and only need a quarter turn to release.

f00lzz · Post by **f00lzz** » 06 May 2008, 18:22

Stempy wrote:I think you really ought to release the pressure, other wise you might end up with an engine bay flooded with LHM. It's not that hard to get at with a long spanner and only need a quarter turn to release.

Sorry Stempy.. couldn't wait to get those spheres on... as it happens only a little dribble from each side. Now for Citerobotics and a drive round the lanes and I'll soon know if I need two for the rear.

f00lzz · Post by **f00lzz** » 06 May 2008, 20:28

Thats Better.... Normal Service has been resumed. Thanks for all you input guys!

Stempy · Post by **Stempy** » 06 May 2008, 21:17

Glad to hear it. I was fooling around with mine today and set the radio to LW 171. I didn't realise just how many times the valves are switched on and off. It doesn't seem to take much extra effort to get them switching.

f00lzz · Post by **f00lzz** » 07 May 2008, 06:29

I thought that was a neat way of checking as well.... Till I went to do it and found my radio only has FM and MW doh!!

DickieG · Post by **DickieG** » 07 May 2008, 18:52

f00lzz wrote:I thought that was a neat way of checking as well.... Till I went to do it and found my radio only has FM and MW doh!!

If your radio is the standard Xantia series 2 model it does have LW, simply search to the end of the MW band and you'll find LW