Hi All
Can anyone advise which of the wires leaving the ECU go to the front EV, I wish to attach a bulb to indicate when the valve is on Soft.Car is 93SED
Thanks David

Pin 1 and pin 2 on the white connector are front and rear electrovalves' 12V supply.
There was another method, used in S1 hydractive: > 4.7k resistor connected between +12v and diagnostic pin. The suspension lamp will stay ON when soft, and goes OFF in hard mode (you can try it on E2 pin on diagnostic socket). The only drawback is that the car remains in hard mode for the first 50meters, and sometimes it takes too long for the car to rise up.

Hi David,

For monitoring the electrovalve switching I would suggest using a resistor + LED rather than a filament 'bulb' - less risk of overloading the ECU electronics. This is what I have mounted on the dash of my Mk2 and you can clearly see by the change in LED brightness as the initial 12v valve opening pulse is followed by the lower PWM voltage (which makes the characteristic buzzing noise from the solenoid).

Ken

Hi Folks, I seem to have a different arrangement, pin 1 is empty, are series 1 different? My ECU is h3/s2003 73810602

What value resistor do you recommend?
David
1993 SED, RP 5625

Pin one is empty because looking at your Rp number i see you have Hydractive 1 and so you only have one electrovalve.
there will be a multi plug behind the o/s Strut top and it will have two thick yellow wires amungst others, these are the feeds to the electrovalve so you can tap into them there where they are much closer to the cabin.

Just out of interest why do you want to fit an led? are there any issues with the ride quality? hydractive 1 cars do not suffer with failures like H2 cars as there are a much more reliable system. a failed sensor or low system pressure will cause a firm ride and if this is the issue should be looked into first.

D

Hi Dean, Ride is a bit firm, should I check main accumulator pressure, how would I know which, if any, sensor has failed?
David

If the ride is firm and you have changed or checked the Hydractive centre sphere's and strut spheres then idealy you need to make sure the car is switching between sport and soft modes, the best way to do it on a H1 car is to drive it, use the hydractive switch by the gear lever to shift betwwen sport and normal modes, you should feel a substantial difference because unlike H2 cars the switch will lock the car in sports mode.

You only really need to check the acc sphere if the regulator is clicking more than once every 25seconds or so.

If there is a difference but the ride seems at bit too firm sometimes it will be worth a go at re callibrating the Pressure regulator, after a few years service the springs in the regs soften and main system pressure drops, this low supply pressure seems to make the car ride in a crashy manor even though the pressure needed for the suspension is still well below that being produced the part of the system that requires higher than suspension pressure fluid to be delivered in order to open the hydractive's softness regulator seems not to like it.

Some cars ive seen producing only 110bar max when they should be producing 175bar and thats a big difference.

D

Abuot the Electrovalve.

Can the electrovalve from Xantia be fitted in an XM? Are they the same?

Regards,

Eryk

Hi Eryk

Yes they are the same for all the later XM's with two electrovalves.
Early XM's until Sept 1993 were fitted with a single electrovalve of a different design.

John