H4 Suspension Ecu - Diode Fitting

After reading about the ECU failures I decided to open mine as a frirst step to faultfinding a hard suspension problem, and it was showing signs of overheating, I made the diode repairs etc and put photos on a webpage here.


http://homepage.ntlworld.com/tinabriddon/h4/


Unfortunately I got carried away and did not photo the two new diodes I fitted, but you can see where to fit them in the very informative PDF file in the other thread on this site here

http://club-xm.com/forum/index.php?showtopic=845

Hi Lez,

Have opened up my S2 2.1TD ECU in preparation for taking it to my local electronics guy so he can replace the MOSFETs for me and solder in some diodes. My board differs from the one in your photo in that there are 2 sets of 2 square solder patches - as opposed to 2 sets of 3 in your photo. As with your photo, there is a space for a 3rd MOSFET.

Just wondered if you had come across this version. I'm assuming that we should be fine installing the diodes across these square solder pads? Grateful for your advice.

I've just got my TD back after more than a year parted from it and the suspension seems stuck in hard. Switching it to sport mode sometimes actually softens the ride! Also - I've noticed that opening the door sometimes triggers it into soft mode, but it doesn't last all that long. I'm assuming that my troubles are electrical.

Regards,
Kiwi

This post has been edited by kiwi on September 16, 2007 07:09 am

Hi Kiwi,

There's a solution to this in an earlier post in the Hydraulic section entitled "Suspension Ecu?, Where?".

There's a photograph of the repair on page 2.

I can confirm that the method described using pin numbers 1, 2 & 15 is valid for the Hydractive II ECU's fitted to all XM's from RP 6383 onwards.

Best wishes

Roy

This post has been edited by mackay1 on September 16, 2007 11:21 am

Hi Roy,

Excellent, thanks - sounds like it is just what I need. Just having some trouble getting my Browser to display the image in your Feb 14 post - doesn't want to play ball with me! In the nature of things XM - I'll keep trying!

Regards,
Kiwi

This post has been edited by kiwi on September 16, 2007 10:31 am

Hi kiwi,

It's not you - there's a temporary server outage at my ISP - hopefully it'll be back up shortly.

Roy

Hi Roy,

Cheers - thats a relief - well for me anyway. I was starting to curse Microsoft again!

Regards,
Kiwi

Hi kiwi,

I'm not too happy about it as you might imagine.

Opening any door or the tailgate should put the car into "soft" mode. It will remain in soft more for 20 secs after all doors are closed at which point it will revert to "firm" mode again. (You can hear the buzzing from front and rear electrovalves when you open a door and after the 20 secs you'll hear it stop, plus there'll be a click as the valves close.) This is normal operation.

More detailed information in the Suspension section of Željko Nastasic' & Gábor Deák Jahn's excellent "The Citroën Technical Guide" which can be downloaded from here.

Roy