Xantia MK1 2.1 estate 1998 - solid suspension

[Armidillo]

OK, I've just checked for buzzing with the door open, nothing.[I did find another 2 spheres, so that makes 8] I have a buzzing, [sounds like a fan on low speed] with the ignition on and and clicking possibly the preheat and pump cut off? #3 fuse is ok.
Is it possible to power up the EV direct? just to see if the valve is engaging . A wiring diagram would be nice if anyone has one
Martin

Happy to admit I was wrong - 8 spheres makes it a VSX & hydractive. xantia_v6's last post is very likely on the money.

Just an idle thought, from my distant memory if the fuse for the EV is removed does it put the car into permanent soft or hard mode ?

Need to do some digging from old posts, but think the valves themselves were updated at some stage and someone has the updated version and found the ride is much improved but no audible buzz and clicking does sound like the EV are dead or no feed to them

If electrovalve is not working for any reason (eg. wire unplugged, fuse blown/missing, or diode failed) the valve is held firmly shut by a spring. Ride stays firm. The updated electrovalves were only fitted to very late Xantias - a 1998 model would not have them.

Cheers
Alec

[white exec]

Martin,
I'll post a suspension wiring diagram for the car in the morning.
It makes no difference whether the suspension regulators are revised type or originals - the buzzing etc is the same, only the hydraulic pipework differs.
Does sound (or rather doesn't) as if the EVs are not receiving power.
The suspension system is fused, so the diagram should help.

Don't attempt to apply 12v directly to the either of the EVs, as they can be irreparably damaged.
They operate together, and should receive 12v for just 0.5sec (pull in), then a pulsed PWM supply of 12v at 25% duty cycle, which approximates to 3v (hold in). The EVs are also polarity sensitive, as each contains a diode, essential to proper operation. Wrong polarity can blow the diode. Need to be treated with caution.

Let's get the ECU supply checked out first. Correct that no suspension ECU power, or ECU unplugged, will result in Firm only suspension. An ECU fault (it runs a diagnostic on itself, and all its connected sensors) normally causes the suspension light on the dash to remain on or flash. The diagnostic (which operates automatically each time the IGN is switched on) does not, unfortunately, make a detailed check on the EVs, but only looks to see that they are connected.

The 8 spheres will be
- 4 corner/wheel (=firm)
- 2 centre (Hydractive, =soft)
- 1 system Accumulator (pressure storage)
- 1 SC/MAC ("anti-sink")
You shouldn't find any more!

[white exec]

Hi Martin,

Herewith electrical pages for Estate, MY1998, RP7483--> (yours is 7493), XUD11BTE
including grounding points and component codes

↓ click to enlarge

Check fuses for ECU supply, obviously.
Any warning light showing on the dash?

Worth checking the black and white 15-way connectors at the ECU for clean contacts.
After that, next step is to check whether each EV is receiving a supply from the suspension ECU.
Best done by unplugging each EV, and connecting in its place a 12v 1W or 2W small bulb (not bigger).
The lamp should show bright (12v) for 0.5sec, followed by dim (3v approx).

d.c. resistance of the EVs is listed as approx 4.8ohm
current for the 12v pull-in is approx 3A
current for the 3v (PWM) hold-in is approx 0.5A