Hi XMexc RS Part Number is:- 2508331936. Very strange looking for RS as their numbers are usually 6 or 7 digits. It does state on the confirmation note that it is an extra range product with 5-10 day delivery. I think that just means they order them from the supplier direct but don't normally carry them in stock. We've had Erwin Sick photocells off them before like this with no problem.

Hi Derek strange it only started dropping when I took the ecu off. Its always stood up before. Might be a coincidence I suppose.

Hi demag et al,

Although RS still print the part in their catalogue I phoned them before to order and I'm sure they don't stockk them any more. I did contact several suppliers when I was looking before so its possible I have them mixed up with someone else. IF so, then the reason I didn't go to RS was because tby the time you pay for the parts and the additional fee because its not a stock item they ended up being £8 each or something ridiculous. I'd check with them on the phone first.

Cheers

noz

Ok Thanks noz I'll check.

The back hasn't dropped today! I can only assume there was some debris in a valve. I think when I have the ecu sorted I will change the spheres and put some hydraflush in. Then I can move on to other things!

You were right noz. Phone call from RS today, no stock.

Do you have any of your stock left noz? If not I'll try and tap Roy up and buy a couple from him.

Hi demag,

Yes I've got a few left. Drop me a PM.

Cheers

noz

PM sent noz.

Thanks.

Hi
I'd just like to say thanks to Roy for his earlier description on how to add the diodes to the wiring.
Just completed mine and instantly heard the buzz reappear from the rear of the car. In fact if you get down on the ground it is quite easy to hear both the front and rear buzzing.

I did take apart and inspect my H5 hydractive ecu and there was nothing noticeably wrong with it. By the way the inside of the H5 ECU is different from any of the photos seen here so there was no possibility of easily soldering the diodes onto the PCB.

Steve

Hi Steve,

I'm glad it helped. It's got to be the biggest payback and the simplest job on the XM. I suspect 90% plus of Hydractive II cars have at least one blown diode.

How much of a difference did it make to comfort / ride.

Cheers

Roy

Yes, beautiful, isn't it? That's the XM Multimedia. It was a limited series produced the last year of production or so, don't know if it was sold anywhere out of France. It had a pc, telephone, internet and satnav installed. Pretty cool for a 1999 car, no?

George

Steve, how often does your pressure regulator click?

You should definitely get a new accumulator sphere anyway, even if your suspension is soft. If it's empty you are obliging the hydraulic pump to work all the time, ad it's not made exactly for that. Also, you don't have any pressure reserves for moments when the steering or your brakes need it.

If your electronics/electrics are OK, and your spheres new and correct spec, then the only thing to check is the pressure regulator adjustment (should be producing pressure in the range 145-170), and that there's not any big leak somewhere -check for heavy LHM return on the pipes at the LHM tank-. Also, riding higher than specified makes a harder suspension (look for height corrector problems). Finally, it could be a leaking electrovalve -they have been known o wear and leak at the outlet side on H2 cars-.

Not sure about the role the antisink plays, but afaik it has nothing to do with the car's ride.

George

Hi All,

There seems to be quite a bit of confusion about the correct location for the replacement diodes on the suspension ECU. This isn't surprising as there are quite a number of printed circuit board layouts and the pictures posted may well not correspond with what you have.

I think the following may help.

In an earlier post in this thread I gave the wiring information for all the options I've been able to identify and suggested that it's easier to connect the diodes to the wiring loom near the 15 pin connector that goes on the white socket on the ECU than solder additional diodes to the ECU circuit board. In many cases this is sufficient to cure the problem (if both MOSFET's are undamaged).

However if you have an ECU already opened with damaged MOSFET's that need to be replaced it is of course possible to add replacement diodes at the same time. Please take care however as this requires a fair degree of skill with a soldering iron. The printed circuit boards are multi-layer and are easily damaged.

All board designs I've come across (referenced by the RP ranges given in the earlier post) can be modified by soldering the replacement diodes to the same pin numbers of the white 15 pin connector (irrespective of the wiring loom colour variations). I'd suggest it's easier to make the connection on the back of the board (the side facing you when you open the casing).

The following picture shows two 1N5408 (a more robust alternative to the original 1N4007) diodes attached in this way:



The pin numbers in the photo (sorry it won't format correctly) are:

15 14 13 12 11 10 9
O O O O O O O
O O O O O O O O
8 7 6 5 4 3 2 1

So the marked end (cathode) of the diodes can be connected to pins 1 & 2. The other. unmarked end (anode) can be connected together to pin 15.

This information comes with the usual health warning - please satisfy yourself that this is correct for your ECU / wiring! The references given in my earlier post to Noz's manual provide this information.

I hope this helps clear up some of the confusion.

Roy

Thanks Roy - that's really useful.