VN05N removal (she's alive!)

Post by **Peter.N.** » 01 Jan 2010, 22:54

Makes a lot of difference to the ride though

DickieG · Post by **DickieG** » 01 Jan 2010, 22:57

Peter.N. wrote:Makes a lot of difference to the ride though

Too right it does, that's how I spotted the problem on my HDi.

deian · Post by **deian** » 01 Jan 2010, 23:03

well paul has one for me to buy, so i will be happy tomorrow

IF the center spheres are good!

Post by **admiral51** » 01 Jan 2010, 23:17

Hi dei
Not to sure on what ecu you are dismembering but if you can give me the location for it on a S2 Xantia Exclusive Estate then if its worth it ill see if there is one on the scrap one at my local dismantlers.

Just to clarify i mean if its compatable then its worth it

Colin

deian · Post by **deian** » 01 Jan 2010, 23:26

it is under the box on the driver side, behind the headlamp, it has two thick connectors to it

but i think paul may have one for me, so hold that thought, thanks for the help, i will report back tomorrow

Post by **admiral51** » 01 Jan 2010, 23:45

No worries Dei ill be up there anyhow,need abreak from SWMBO.
If there is one on it ill grab it.Come to think of it ill grab all the ECU/Relays i can find and then photo them got to be of use to some one

Dei when you say 2 thick wires connected to it am i looking at a relay type box or something a bit bigger

Colin

DickieG · Post by **DickieG** » 01 Jan 2010, 23:47

admiral51 wrote:Not to sure on what ecu you are dismembering but if you can give me the location for it on a S2 Xantia Exclusive Estate then if its worth it ill see if there is one on the scrap one at my local dismantlers.

Just to clarify i mean if its compatable then its worth it

S1 and S2 Hydractive ECU's aren't compatible

if however you know of an available S2 ECU I'd certainly be interested in it.

deian · Post by **deian** » 02 Jan 2010, 00:09

admiral51 wrote:No worries Dei ill be up there anyhow,need abreak from SWMBO.
If there is one on it ill grab it.Come to think of it ill grab all the ECU/Relays i can find and then photo them got to be of use to some one

Dei when you say 2 thick wires connected to it am i looking at a relay type box or something a bit bigger

Colin

yes it's a relay type box cover thing, just pop the cover off with two tabs on the side, and all the ecu's will be there, the hydractive one is the one closer to the engine, but with two big connectors going to it, one white and one black,

hi richard, i didn't know that about the ECU's, mine has the following writing on it, Valeo, 73810802, 961049310, 12.94, H4, S2G2G, and the car is a 94/95 registered 1.9td VSX

also as it happens, the wiring colours on mine is exactly the same as the technical documents i have say they should be, but i've seen a thread on here showing pictures the wiring in different colours

out of interest, what are the differences that make them incompatible?

Post by **admiral51** » 02 Jan 2010, 00:21

Right then guys i will have a look around today(sat) and see what i can find.Will take some pics of what i leave behind so if its worth a return trip ill go and retrieve whats left

Colin

PS if anyone has a pic of the area/location i should be looking in it would be most appreciated.By the way its a S2 Xantia estate Exclusive with leather interior etc minus n/s mirror and drivers door but the rest appears to be intact inc full leather interior although that was on Dec 29th and no wheels.Dash looked good inc wood trim

DickieG · Post by **DickieG** » 02 Jan 2010, 00:23

deian wrote:
admiral51 wrote:No worries Dei ill be up there anyhow,need abreak from SWMBO.
If there is one on it ill grab it.Come to think of it ill grab all the ECU/Relays i can find and then photo them got to be of use to some one

Dei when you say 2 thick wires connected to it am i looking at a relay type box or something a bit bigger

Colin
yes it's a relay type box cover thing, just pop the cover off with two tabs on the side, and all the ecu's will be there, the hydractive one is the one closer to the engine, but with two big connectors going to it, one white and one black,

hi richard, i didn't know that about the ECU's, mine has the following writing on it, Valeo, 73810802, 961049310, 12.94, H4, S2G2G, and the car is a 94/95 registered 1.9td VSX

also as it happens, the wiring colours on mine is exactly the same as the technical documents i have say they should be, but i've seen a thread on here showing pictures the wiring in different colours

out of interest, what are the differences that make them incompatible?

The only thing on the ECU that will help you is the date (S1 or S2) but even that doesn't tell you whether its been programmed for an XM or Xantia.

The problem with them is that S2's were programmed for the 16 pin plug whereas S1 were programmed for the 30 pin and S1's have a brake pressure sensor whereas S2's don't. When the ECU on my HDi went forth I tired using a S1 ECU but it kept looking for the brake pressure sensor for the first five minutes or so before it gave up looking. During that time the suspension was stuck in hard mode, Lexia's are unable to do anything about that as the ECU's can only be programmed once. Whether an S2 ecu can be used in a S1 car I can't tell you.

deian · Post by **deian** » 02 Jan 2010, 00:33

well pauls one is a '95 one so it should be ok, mine is 30 pin anyway, didn't know the s2 dropped the brake pressure sensor, tbh i only thought it was just a simple on/off switch, it appears so on the diagram, there may be more to it, the ecu might measure the voltage resistance in relation to line pressure

good idea about taking pics at the scrappies colin, i will try to do the same when i'm at a scrappies next

addo · Post by **addo** » 02 Jan 2010, 11:49

admiral51 wrote:PS if anyone has a pic of the area/location i should be looking in it would be most appreciated.By the way its a S2 Xantia estate Exclusive with leather interior etc minus n/s mirror and drivers door but the rest appears to be intact inc full leather interior although that was on Dec 29th and no wheels.Dash looked good inc wood trim

Struth! As a complete car, it'd be worth £2000+ here.

If DG passes on the Hydractive box (and it's not silly money) I would be up for it.

xmexclusive · Post by **xmexclusive** » 02 Jan 2010, 12:22

Hi All

From my XM suspension ECU investigations I can add a slightly different slant on things. DickieG your Xantia summary was very useful and filled quite a few gaps for me.
The design of the electronics in the Citroen ECU's typically date from around 5 or so years before the production start for the car model. Over the production years car model design and electronics design is modified/improved/cheapened in a series of small progressive steps.
With the XM the first suspension ECU design (H or H1) dates from about 1985. There was a rapid series of changes around 1990 (H2, H2B & H3).
These all service the HYDRACTIVE 1 suspension design.
For the XM the next big change was 1994 with HYDRACTIVE 2 suspension using the H4.3 suspension ECU for the XM mark 2.
From DickieG's summary I realised that the original H4 suspension ECU predates this and was designed around 1992/1993 for the launch of the Xantia. That the controlling software needed to change for the change in OBD plug was an interesting fact that was new to me as I think the XM retained the 30 pin plug throughout production.
All these ECU's were made to a series of generic designs with the unique model/version controlling program hard coded into the ECU as part of the manufacturing process giving each one a unique part number.
For the H5 version of the ECU (final XM one) there was a significant change with the electronics. All H5 suspension ECU's were made to a single common design with a blank memory device waiting for the car/model specific program to be installed. This progamming could be done once only using the LEXIA.

I think that ECU's will be one of the major supply problems and a critical failure item as our cars age. As a result I have started to collect a few cheap spares now while they can still be obtained at realistic prices.
I would recommend that a few more of us collect or offer on spare ECU's where we can. Once they are crushed they are gone for good. That said do not pay over the odds. £10 for an ECU is tops for me.

John

deian · Post by **deian** » 02 Jan 2010, 12:31

I'm paying a tenner for pauls ecu and i am happy to do so.

I can pay a tenner for 5x BUZ11 from RS, I've cancelled the order for now to pay for the new ECU, I may re-order them when the stock comes in as they are becoming hard to get hold of, and the problem is, as we all know these ecu's can die due to the electrovalve diodes or poor soldering of new transistors

So when they do become even more rare, even broken ones should be saved so someone can fix them up when the pot runs dry.

Mine is a bog standard H4.

Do you think we should make a 'sticky' with hydractive part numbers in the hopefully soon to be supersticky, as well as the missing (/hard to locate unless you know) 'sphere part numbers', which can be had on 'old-guy' site with his permission, even just a link?

Post by **admiral51** » 02 Jan 2010, 13:03

Sorry guys just been up the scrappy and the car has gone they crushed it along with a S1 TD

Will keep an eye out in the future as i visit them quite often so if i can spot any ECUs/Relays especially from Hydractive/Automatics ill squirrel them away

Colin