Permanent Front Electrovalve fault?

[dei9]

Hi all,

I've had a Lexia on the car, and found the hydractive ECU to have three faults, the usual steering wheel angle sensor, a weird fuel pump fault (what the hell is that about), and the one that didn't clear was the permanent front electrovalve fault. What does that mean? Does it mean the 'actual' electrovalve is faulty or broken or does it mean the transistor is broken? The back one wasn't faulty. When the system was tested, it also showed the brake pedal as being pressed? It wasn't and it's not the switch on the brake pedal, because I did an ABS system check too, and it confirmed the brake pedal switch was fine.

Another clue is that when I put my little arduino setup onto the electrovalve the front one worked briefly, I couldn't hear much from the back one either, (i've upgraded the wires to handle a 3A load) now, but not tested on the rear ones with the upgraded wires. I'm hoping it's the transistors, but I'll check the resistance of the coils and also the continuity.

Any ideas about whats it could be or whats going on?

Got a mate coming down with an oscilloscope tomorrow too, that'll be interesting.

Thanks, Dei

[DickieG]

IIRC on S2 Xantia's the brakes are shown as always on so I'd ignore that one, when I had a VN05 go pop in the ECU Lexia displayed all manner of faults plus when I opened up the ECU there was scorching around the VN05.

[dei9]

i opened mine up and there was no scorching whatsoever, but i'm assuming they could still be borked, i'll order some in.

[Northern_Mike]

If you apply a feed to the valves do they operate?

[dei9]

A brief but straight 12V? I don't know yet, I will check that tomorrow, I can jump the pins to do that right? The permanent + to pin 1? Or is the one after ignition on cleaner? I would leave it on check the bouncyness of the car (if they work). I shall report back tomorrow morning.

[Northern_Mike]

Yes. The valve will take it ok and give you a clue as to whether it's the valve or electronics that are iffy.

Just a thought - are you sure they're not working, and are you sure the spheres are ok? I had an Activa where the valves were working but the spheres were so flat it was so hard it was undriveable. It literally bounced the wheels off the ground over some bumps.

Sent from my SM-N9005 using Tapatalk

[dei9]

yea, there is no humming sound the electrovalves do, and when the lexia was on, a test of the different parts were done, and it showed everything change, and from time to time the state of the system would switch from firm to soft just ever so briefly, and you could see the rear electrovalve state go from 0 to 1 when it happened, but the front one remained at 0. I do find it bizarre that it kind of kicks in from time to time for a brief second, I will might check what current gets into the system, and maybe spray some wd40 down the pins, and along the wires. It's all a bit weird tbh.

[dei9]

ok, so i'm going to change the transistor, i have the board in front of me, with the plugs at the top, which transistor is for the front electrovalve? top one or the bottom one?

[dei9]

It wasn't even connected!! The computer works because the back solenoid works, but I took out the front electrovalve transistor and soldered a new one on (untidily), so as soon as I find the connector to the front electrovalve i'll plug it in and MAKE it work.

[CitroJim]

Dei, bet you'll find the transistor was fine... Why did you swap it before finding the electrovalve connector?

Or have I read that wrongly?

[PIT]

And did you check for two clicks in the front, when you open a door? This usualy means a faulty diode in the valve.
And btw, the brake info in hydractive ECU is not from the pedal switch. It comes from the hydraulic switch which is activated when a certain pressure is applied to the brakes. This means heavy braking and the ECU will switch to FIRM mode to prevent the front to go down and the back up.

[dei9]

Dei, bet you'll find the transistor was fine... Why did you swap it before finding the electrovalve connector?

Or have I read that wrongly?

No you read it right. I wasnt expecting the electrovalve to be disconnected. What an idiot I am lol. I'll order a new one in and tidy it up anyway. Still going ahead with my Arduino project though

[CitroJim]

I've done very similar in the past Dei. We all do... It's perfectly normal...

Still going ahead with my Arduino project though

Good. I'm following with interest as that'll enable you to vary all the parameters at will.. Something impossible to do with the standard ECU...

[dei9]

Hi Jim,

I found the wire that goes to the solenoid, it's not so easy to put in, but I noticed the solenoid can turn around, is this normal? Or is there something more sinister going on?

Still, I plugged it in and it didn't work, I need to do a tidier job of soldering that VN05N in, so I've got 3 on order today, one for the existing ECU and two for my arduino, wondering how I could incorporate a multicoloured LED into the switch (that'll be fun).

Thanks, Jim and all for your continued help, this forum is a nice place to be.

[CitroJim]

Dei, it is perfectly normal and proper that the solenoid spins around.

Nothing to worry about at all