Russ's 2.1 SED Auto now in Mandarin

[xantia_v6]

But on the drive home it felt far more solid and jittery than when it was forced into soft. It cannot be spheres as it was nice and soft before.

It could be the corner spheres which would not have been having much effect before.

[Dieselman]

If the bulb isn't blown, the lack of illumination will be the ECU, which may be locked up, hence won't talk to the ELIT.

The spheres are a good point, you should have tested them while at Jims.

[normanlindley]

The steering wheel sensor allways comes up on the lexia it seems to be a weak point on the Xm it can be cleared one min then after a short while it comes up again I have seen this on quite a few cars and it tests OK on diagnostics what do you think Jim.

Norman

[russ92xmsed]

Thanks for all your suggestion. Very interesting. The reason why initially we thought everything was fine, was because it seemed to perform well on the test drive we both took straight after reconnection.

The spheres were all either re gassed or replaced in 2012, and with the amount of driving I do.... Ie not much, they should be good. The ride in sport mode is not bone jarring, or very uncomfortable, it is just a lot lot firmer and more solid than before.

I think Will you might be spot on with the ECU locking itself up. There was no way both elits were accessing the ECU.
Can it be unlocked though.....

[xmexclusive]

We are dealing here with a HYDRACTIVE system not a HYDRACTIVE II.

For what it is worth here are the workshop manual pages.

Hyd1.jpg

Hyd2.jpg

Hyd3.jpg

Hyd4.jpg

Hyd5.jpg

John

[russ92xmsed]

Thanks very much John, I'll have a close read of all this.

[russ92xmsed]

And the fun and games continue. I 'accidentally' reset the ECU yesterday without realising!!... I was fiddling around with another little issue amongst the irritating weather. I believe disconnecting the battery ( I do know about this little trick from the other cars) for 10 mins is supposed to reboot it. Anyway it didn't work, and wasn't expecting it too really, its going to take more than that to solve this problem. The orange light is very much inactive. Just been out in the car doing some errands and the ride has to be locked into sport mode, it hadn't changed at all... it is soooo firm.

But what I am not understanding, if hypothetically the car is in soft mode now with a firm ride, (all six spheres being used, but suspect corner spheres) why the very good ride before albeit locked into soft mode using all 6 spheres, would then suddenly be rubbish once everything is all connected again. I would expect no difference apart from the hydractive doing its thing when you press on.

So i am convinced it has to be stuck in sport mode, it is soo different and feels more solid all round, worse in the back due to less weight I suppose.
Anyway, I parked up, switched off, opened the door and the front dropped. not to the floor but enough to surprise!!! Never done that before. Its also slow to rise from rest. It used to pop up nice and quickly. Anyway, it didn't drop again when i got back. So this is clearly far from right. I might have to disconnect everything until I can fit Pauls spare ECU at the X rally, just to save the other suspension parts and have a decent ride.
To me it just points to a completely scrambled ECU.

Im going to go and probe the plugs i think later, using Johns info. Plus I have windows to fix too. Got to conquer that problem, the sun is shining. Perfect!

[Ciaran]

My last S2 had intermittently hard suspension, more often staying hard than soft, for several months.

Eventually I had the fault codes read out with an Elit. The steering wheel sensor featured prominently as it always does, but after the fault memory was cleared, I noticed for the first time ever in five years of owning the car, that the orange Hydractive light in the dash lit up at ignition switch on, rather than just when Sport mode was selected. This condition (no light) had persisted over numerous battery disconnects through the years. From that point on the suspension behaved much better and regularly stayed in soft.

Seemingly the light on for a few seconds at ignition is a status indicator that all is well within the ECU, and if it's not coming on at all, or is staying lit permanently then you have stored faults.
Would be worth having a read out of them if you can Russ, even if the cause of the fault condition has since been cleared, the ECUs tend to misbehave when the logs are filled with extensive amounts of crap.

Ciarán

[Ciaran]

Anyway, I parked up, switched off, opened the door and the front dropped. not to the floor but enough to surprise!!! Never done that before.

Yessss, had that one a few times before.
The standard behaviour of the suspension is that when any of the door or tailgate switches are triggered, that the computer will close the centre spheres, putting the car in hard mode. The idea here is that it will prevent any sudden body movements or alterations in height (that are more prolific in soft mode) from happening while passengers may be getting in or out of the car.

What can happen sometimes is that the pressure in the centre sphere is significantly more or less than that in the side spheres, so when the valve opens, the car either rises or falls rapidly, depending on the pressure differential between the spheres. In your case, the pressure in the centre must have been less than the sides, so when the valve opened the higher pressure from the front wheel spheres rushed in to the lower pressure area in the centre, causing the car to drop.
Sometimes this can happen quite violently, right down onto the bump stops, not a fun one!

There are other dynamics involving the pressure required to physically open the centre valves too, but I can't 100% remember that.

Either way, if you follow John's troubleshooting guide there you should be able to rule out any electrical issues, and if the problem persists it may be worth checking the output pressure of the regulator as this can have a significant effect on the proper working of the Hydractive.

Ciarán

[russ92xmsed]

Hi Ciaran,

Mine is a series 1 with H3 ECU, which is meant to be the better ECU on the hydractive 1 system. Not on mine it I seems!

I went to Jims on Saturday, and he tried both elits on it and it didn't want to know. Having none of it! So as Will has said before, it must be locked up for some reason. Before it was all nice and soft because it was bodged to be soft all the time. Now it's all connected it appears there is a big problem. Im certain it is in permanent sport mode. The ride is so clearly different. I'm dying too try another ECU to see it sorts it out and then can tell what sensor if any have gone pop.

That is very interesting what you say about the centre sphere, it dropping and the system pressure. I have a nagging feeling the system pressure is too low, hence why maybe it is stuck in hard mode. It might also mean the Hydractive spheres might be too low in pressure then too.

What is really confusing is when all switched off, close the door, you can bounce the car quite easily, then the electrovalve times out and it's gone hard. I'm going to see if it repeats this with the engine on. If it's stuck in sport when all activated I surely it will be solid when bounced.......