Xantia Activa Ph2 - Firm State help please

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Renanek9
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Xantia Activa Ph2 - Firm State help please

Post by Renanek9 »

Hello

I was suffering from Activa's FIRM STATE issue. Low voltage (Around 1.5v), stucked on FIRM, solenoid clicking all around and etc....
WhatsApp Image 2021-07-06 at 19.58.01.jpeg
I Have an extra suspension ecu (almost brand new btw). I´ve tested and its all good and works fine. For precaution, i did the diode mod on this ecu and everything is still fine.

WhatsApp Image 2021-07-06 at 17.10.49.jpeg
WhatsApp Image 2021-06-28 at 19.36.04.jpeg
BTW does anyone ever seen an Activa ECU with these parameters? Very strange....
This is my extra ecu (manufactured on 2000)
WhatsApp Image 2021-07-06 at 17.14.18.jpeg
My OEM 97 ecu shows this:
WhatsApp Image 2021-07-06 at 17.14.18 (1).jpeg

Well.... On Saturday I took the car to my house and everything was fine. On Sunday, when I went to take it to another garage, I felt it stiffen and start to make several clicks in the rear when I parked it again.
I even felt a CLUNK on the right rear (passenger) every 4-6 seconds (probably rear ram)
When I checked with Lexia, I found everything was fine, despite the suspension being locked in FIRM again, but showing a correct and normal voltage
WhatsApp Image 2021-07-06 at 17.10.01.jpeg
.
What do guys suggest? Remove rear rear solenoid to clean/stretch the small spring? Anything else I should do or test?

There is a small leak in the Rear Ram. But really small. I imagine this is not the problem, since 1 day before I drove it perfectly.

The car keeps going up and down as it should, although it doesn't stop getting CLICKS

Thank you

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white exec
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Re: Xantia Activa Ph2 - Firm State help please

Post by white exec »

That sounds like an intermittent connection. A power interruption would cause Firm.
What does the suspension light do when the IGN is turned on? Does it indicate any fault?

Renanek9
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Re: Xantia Activa Ph2 - Firm State help please

Post by Renanek9 »

white exec wrote:
07 Jul 2021, 05:50
That sounds like an intermittent connection. A power interruption would cause Firm.
What does the suspension light do when the IGN is turned on? Does it indicate any fault?
Lexia doesn´t show any error at all.... all clear

There is something interesting going on with this new ECU (2000). When I turn the ignition switch ON I see the suspension button light turn on and off. Almost like a check
With my old and original ECU (1997) I never saw that happen. Weird.....

I don't know if it's part of the symptoms or if it's a change due to being a younger ECU.

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white exec
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Re: Xantia Activa Ph2 - Firm State help please

Post by white exec »

The hydractive ECU runs a diagnostic on itself, and the connected sensors/EVs, every time the IGN is switched on. The dash light should illuminate, and if all found OK, will then go off. If it stays on, or flashes, that indicates a fault.
The only other time it should light is when Sport mode is selected.

There were several evolutions of the Hydractive (Hydractive II) ECU, with the final ones being shared by XM and Xantia.
These late ones contained the look-up (operating) parameters for both cars, and on installation of a new one would (should) be programmed to operate either as Xantia or XM. This was a one-off choice, and could not be undone or reversed.

This might explain why the two ECUs operate differently. If you can post a photo of the large label (will likely say H4, H5 etc) on the two, it might be possible to shed more light on the ECU type. Maybe Lexia would show which car they were programmed for. I'm not sure what would happen if an XM-selected ECU was put into a Xantia, or vice-versa.

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Re: Xantia Activa Ph2 - Firm State help please

Post by Renanek9 »

white exec wrote:
07 Jul 2021, 13:54
The hydractive ECU runs a diagnostic on itself, and the connected sensors/EVs, every time the IGN is switched on. The dash light should illuminate, and if all found OK, will then go off. If it stays on, or flashes, that indicates a fault.
The only other time it should light is when Sport mode is selected.

There were several evolutions of the Hydractive (Hydractive II) ECU, with the final ones being shared by XM and Xantia.
These late ones contained the look-up (operating) parameters for both cars, and on installation of a new one would (should) be programmed to operate either as Xantia or XM. This was a one-off choice, and could not be undone or reversed.

This might explain why the two ECUs operate differently. If you can post a photo of the large label (will likely say H4, H5 etc) on the two, it might be possible to shed more light on the ECU type. Maybe Lexia would show which car they were programmed for. I'm not sure what would happen if an XM-selected ECU was put into a Xantia, or vice-versa.

Here we go

My OEM ECU (97) and its information via Lexia.
ecu oem.jpeg
ecu oem 2.jpeg
ecu oem 3.jpeg
ecu oem 4.jpeg
ecu oem 5.jpeg
ecu oem 6.jpeg
My SPARE ECU (2000), that i´m using since last saturday. The one that turns the suspension light on for "checking" before the ignition
ecu 00.jpeg
ecu 00 2.jpeg
ecu 00 3.jpeg
ecu 00 4.jpeg
ecu 00 5.jpeg
ecu 00 6.jpeg
Comparing the photos I think we can say that they are completely identical, even in the information of each one

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white exec
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Re: Xantia Activa Ph2 - Firm State help please

Post by white exec »

Thanks for those photos and detail - a big help.

XM and Xantia originally each had their own Hydractive_2 suspension ECUs, but from version H4 onwards (the final one was H5), there was just one ECU (used in both cars), that contained the software and coding for both XANTIA and XM. There was one part number for this ECU, used in both cars. This applies to both H4 and H5 types.
H4 suspension ECU coding.jpg
This page explains
(a) that a new ECU must be programmed/coded for the correct car
(b) the process is one-off, and not reversible
(c) that a Xantia ECU must not be used in XM, nor vice-versa

Some more info here; see paragraph 3.3 in particular.
Again, same applies to the H5 versions...
Telecoding H4 XM-Xantia p1.jpg
Telecoding H4 XM-Xantia p2.jpg

From your photos, those two ECUs are indeed identical, but your Lexia screen shots show that the first one is showing as XANTIA, while the other one is showing --------.
That suggests the second one has not been car-coded, which might explain why they are behaving differently.

Hope helpful.

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Re: Xantia Activa Ph2 - Firm State help please

Post by Renanek9 »

Thank you for the explanation. In fact I was very suspicious that it was an uncoded "brand new" ECU due to its small number of "acesss counter". This is actually an advantage, right? A Brand new activa ECU?

And knowing that it has the same functionality for both cars, it works, even without defining which model it was targeted at, right?

In fact it works perfect since I used it on Saturday and everything went as it should. It wasn't until the next day that things started to go wrong.

What should I do? Test my other ECU on it and see if the error persists? Or try an electrovalve intervention or something like that??

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Re: Xantia Activa Ph2 - Firm State help please

Post by Renanek9 »

Or Do you think I should try to telecode it to identify it as Xantia model?

Btw this should be almost mission impossible by these days... lol

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Re: Xantia Activa Ph2 - Firm State help please

Post by white exec »

There are Xantia Activa experts here, so will let someone else help with the specific Firm problem.

The only people who could telecode (program) that new ECU would be a Citroen main dealer.
The software for doing it may well reside on some more recent diagnostic kit they have, rather than on the old ELIT etc equipment.
Explain to them EXACTLY what is needed, because it has to be got right first time, by the sound of it. Show them the pages above.

It is possible that one of the settings on the H5 (Xantia - XM petrol - XM diesel....) is a default one, and which operates even if not telecoded. I will search around for this info, which could be somewhere. The page says that an ECU which has not been telecoded will cause the dash light to be on for 30secs each time the IGN is switched on. Does this happen on your car?

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Re: Xantia Activa Ph2 - Firm State help please

Post by Renanek9 »

I actually thought the H5 ECU (green connector) was exclusive to ACTIVAS only and not shared with any XM.

I want to imagine that the ECU works even without being telecoded, as my car looked pretty normal on Saturday. But in fact we need to understand what the purpose of TELECODE it and have a predefined version (when it is accessed via LEXIA) if the pages above says it is the same ECU. What a mystery...damn

About light. I didn't notice the dashboard light coming on for 30 secs. The only light that I´ve noticed was the one that I had previously reported: the suspension button LED. I will try to make a video.

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Re: Xantia Activa Ph2 - Firm State help please

Post by Renanek9 »

Finally, after a few days of use, the car came up with some error to guide me
novo2.jpg
And suddenly he showed up in Soft state again. But it's intermittent. Just turn off the car and turn the key again and it returns to the firm state.

I believe I need to remove the electrovalve from the rear and perform a cleaning. besides trying to stretch the smaller spring a little, correct?
novo.jpg

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Re: Xantia Activa Ph2 - Firm State help please

Post by xantia_v6 »

The ECU cannot detect any mechanical or hydraulic fault in the electrovalves, it can only detect the electrical current drawn by the valve coil.

The usual causes of that fault are a failing diode in the coil, or a loss of connection between the ECU and the valve.

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Re: Xantia Activa Ph2 - Firm State help please

Post by Renanek9 »

xantia_v6 wrote:
22 Jul 2021, 07:10
The ECU cannot detect any mechanical or hydraulic fault in the electrovalves, it can only detect the electrical current drawn by the valve coil.

The usual causes of that fault are a failing diode in the coil, or a loss of connection between the ECU and the valve.
I´ve already did the "Diode mod" on my ecu to prevent that diode failing

And yes, i believe that is something mechanicaly wrong with the electrovalve

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Re: Xantia Activa Ph2 - Firm State help please

Post by white exec »

The EV (electrically) should draw approx 3A for 0.5sec from its initial 12v supply, then drop after the 0.5sec "pull-in" to what looks like around 3v. The 3v is actually 12v square-wave PCM, at 25% duty cycle. This is the solenoid "hold-in", aided by the diode.

The EVs can become mechanically 'sticky', or their small internal spring become compressed/weakened with age. It is possible to remove and stretch the spring a little, to restore its action. The solenoid must be unscrewed from the valve body to work on it; car needed, as the body of the solenoid is soft aluminium, and on a very fine thread.

The hydraulic action of the EV can be partly tested by looking at the amount of LHM that is expelled from the EV's return pipe. If all ok, each time the valve operates, a tiny volume of fluid should expel. If none, or flow is anything like continuous, the action of the valve is faulty.

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Re: Xantia Activa Ph2 - Firm State help please

Post by Renanek9 »

Hello my friends.

The End of Mystery. I got another Activa ECU to test it in my car. Immediately the car was perfect, suspension in SOFT STATE, ACTIVA system up and running. Everything working as it should. I returned my ECU to the car and the problems returned.

So I had the idea to remove the DIODES installed on the board. Voila! Everything normal and working again.

I believe that my solenoid valves are perfect and all with their diodes in perfect condition, and having put MORE DIODES (Diode used was the 1N4007) on the board has affectef the functioning of the entire system.

What do you say? I thought I could leave the diodes on the board as a prevention and, in the end, I ended up creating a problem