ekaftan wrote:Mandrake wrote:Before getting too carried away with looking for replacement ECU's, why not remove the bodged extra wires (take note of where they were though) and see what happens ?
Update: I did just as you suggested and fixed the wiring. I removed two wires: one jumped the tachimetric relay output (ie, positive when engine runs and a small 12 volt yolt on key to run) with one of the the white wires. The other jumper jumped the two white wire together.
Right, so they're supplying 12v when the ignition is on to both electrovalves
This will definately overheat them, but if you're lucky they may not have suffered permanent damage from this.
Results: now the car is a stiff as a rock. No suspension movement at all when pushed.
Conclusion: the jumper was there to mask the fact that all 4 corner spheres are completly shot and that the Hydractive ECU is either bad, or detects a fault and does not activate the valves at all.
Sounds spot on to me! The hard mode is supposed to be quite stiff, but there is still movement, and the car should be still perfectly drivable stuck in hard mode, it will ride large bumps well but will be fidgety on small bumps.
If it's completely rigid as you say it is, then you'll find it will bounce all over the place like a car with cut springs...
Car is parked (its undrivable this stiff) until I replace 4 spheres tomorrow.
Next thing to do is try and see it electrovalves measure 4 ohms.
You probably also want to do the test I mentioned previously testing the electrovalves with 12v supplied via a 15 ohm resistor, to confirm the internal diodes are ok.
Also you can use this as a way of testing the hydraulic operation of the electrovalves to see if they both still function ok, even if the computer isn't currently working -
With both the plugs unplugged from the HA2 computer, connect 12v via the 15ohm resistor to pin 1, and ground to pin 8 or 15, then bridge the resistor with a clip lead for a second or so, and you should hear the electrovalve click, when you remove the cliplead the voltage will drop to about 3v which is enough to keep it active without overheating - then try bouncing the car at the front to see if its soft or not.
Do the same with the rear using pin 2. By doing this test you can manually operate the electrovalves to see if they're working.
Question: how can I reset the Hydractive ECU? Pull the fuse?
I'm not sure that it needs reseting, but if there has been bodgy wiring connected etc, then I would certainly remove the fuse for a couple of minutes and put it back, as it does run off direct power, not off ignition switch power...
Regards,
Simon
