Xantia stuck in hard mode

[xantos]

Hello!

Recently I have bought a Xantia Activa 2.0 TCT. I have searched throughout the forum and I got some very useful information.

But still there is a problem that puzzles me. I think that the electrovalves are not working. I have done the Diode Mod, but I still get a harsh ride.
I can't hear the electrovalves buzzing and when I open the door and close it the car is stiff.

I get voltage from the electrovalve pin when I put one end from the voltmeter to the pin (both) and the other to + on the battery. Is that OK?
Is it possible that the electrovalves (both) are stuck? I have tried to give them a few gentle wacks with a hammer with no result.

In the picture there are the diodes that I have soldered (ok not very neat) and I think it's right. Right?

The car also rises first on the right side and needs quite some time to level the left side. I belive that the problem is one of the spheres is bad (I don't know the condition of the spheres), beacause there are a lot of bubbles (picture 2) in the LHM tank when I put the car on low (but none on high). Maybe the air in the brakes is to blame? They are working OK btw.

Thank you for your replies.

[CitroJim]

Hi Xantos and welcome to the wonderful world of Activa ownership!!!

Where to start? Have you seen the buyers guide down in the Activa area of this forum? It gives much useful information on testing the suspension...

The electovalves don't stick as such but can fail to operate either because of no electrical signals to them or because of low hydraulic pressure.

Your diode mod looks OK but in an Activa you need three diodes as the Activa has an extra electrovalve for the roll stiffness regulator.

Basically, to check the electrovalves are receiving power you really need an oscilloscope as they are supplied with a squarewave signal at around 1KHz which is why you can hear them buzzing. However you can test them with an ordinary meter and you should see a voltage of about 3 or 4V between the banded end of the diode and earth (battery negative) which will remain there for a good few minutes whilst a door is open even with the ignition off..

If you see no voltage on any of them, noting that the Activa roll stiffness electrovalve only operates during very hard cornering, assume the hydractive ECU electrovalve drivers are dead due possibly to the diode mod not being carried out a long time ago. If this is the case the ECU can be fixed but it's a skilled job. Replacement Activa Hydractive ECUs are like rocking horse poo so don't hope to find one very quickly!

It'll be a good idea to get a Lexia or ELIT diagnostics on the ECU as that may tell us something useful.

If the main system hydraulic pressure is very low this can cause the valves not to switch over but that won’t stop them humming. Your problem looks electrical.

Something else to check is that someone for some reason hasn't pulled the fuse to the Hydractive ECU. This is normally F8 (yellow 20A) in the engine bay fuse box although the very last (W plate) ones may have the fuse in a different place. This can be done as a bodge to cover up a leaky electrovalve as forcing permanent hard mode by powering off the ECU can often mask the leak.

Your LHM does look frothy... More likely an air leak on the suction side of the pump or a sphere is dying and releasing nitrogen into the LHM...

Anyway, lets take one problem at a time. The Activa learning curve is steep...

Hope that helps get you started. Come back with results and we'll take it from there...

[xantos]

Thank you Jim for your quick reply.

Must agree. It's really a wonderful world owning an Activa.
Yes I have read a lot of posts involving Xantias, but there is allways something. It's an Activa

There are three diodes soldered to the cables (hard to see from the picture) and I had taken appart the ECU. I found there were some "cold" junctions and soldered them. The VN05N relays looked fine and not burnt, but needed a little bit of soldering. Maybe made a mess of it, but I was quite happy with the job...

I think that the electrovalve problem is electrical. Maybe some burnt wire or a bad junction. Will do the test with a voltmeter like you said, but I think there is no electricity to the valves. I believe if they are operating you should feel a little shaking if you touch them. Mine are cold as stone. Made the fuse check and found one 5A burnt in the engine box. It was the one that illuminates the "sport mode" button, so that was one problem solved Others were fine. Maybe there is another fuse hidden somewhere...

Lexia was allways an option. Just having difficulties getting my hands on one.

[CitroJim]

You will hear the electrovalves humming but won’t feel them. they don't vibrate that much...

Good to hear there's three diodes!

The VN05s can fail without looking completely burned.

As for the fuse I'd be inclined to check that power is in fact getting to the ECU.. here's a circuit diagram of the Hydractive system... Note that this applies to the early and mid S2 but the S1 and late S2 is very similar.

Lexia was allways an option. Just having difficulties getting my hands on one.

If you're in the UK I'm sure there'll be a member near you somewhere that will be able to help. There is a 'Supersticky' thread listing those with a Lexia willing to help out...

[Hell Razor5543]

And here is that list CitroJim mentioned;

http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178

[xantos]

The power is getting to the ECU. I tested the pins 1 and 2 on the black connector ( http://homepages.igrin.co.nz/simon/imag ... pinout.jpg" onclick="window.open(this.href);return false; ) and there is voltage on both pins (pin and (-) on the battery). There is no voltage on pin 1 and 2 on the white connector (pin and (-) on the battery). I get voltage if I connect pin and (+) on the battery. No voltage also if connecting pin 1 or 2 to pin 8 or 15 (earth).

Should the electrovalves function also if the car is on stand with the engine on?

The circuit diagram is a bit to much for me but will try to ask a friend that studied electronics to help me.

I saw the sticky listing members with Lexia but no good for me as I'm not from the UK.

[CitroJim]

Should the electrovalves function also if the car is on stand with the engine on?

Yes, it should be in soft mode all the time the ignition is on. The only time really it'll switch hard with ignition on is when you're cornering hard..

Soft mode will remain for 30s after switching off the ignition and closing all doors. It'll switch to soft mode whenever a door is opened with the ignition off and if you leave a door open soft mode will remain on for many minutes...

[xantos]

Now I've realy done a STUPID thing...

Trying to fix the electrovalve problem, I've switched a relay in the fuse box and tried to start the engine.
Now the engine won't start (it's cranking). Even tried to connect it to Autocom diagnostics, but it's not responding.

The big question... What have I burnt?

Stupid, stupid, stupid...

[xantos]

Check this out...

I have been messing with the electronics and now this has happened.

http://tinypic.com/player.php?v=j10xdy&s=5" onclick="window.open(this.href);return false;

Is there a short circuit under the dashboard or the computer has gone completely MAD...

The engine doesn't start. It just cranks. Even with hazard flashers on. The lights, siren, central locking, front windows, blower are not working. Hazard lights, front and rear wiper, rear windows, rear window heating are working. I also don't get the "key light" on the dashboard when contact is given.
Was messing with some relays, thinking that maybe that's the problem of electrovalves. So I moved a relay to a different connector (see picture) and tried to start the engine and it didn't start just cranked. Then moved the relay back to it's own spot and since then I have problems. All the fuses are ok, double checked them (engine and cabine compartment).

I think I made a short circuit somewhere (where?!), since I have unplugged the computer and when hazard flashers are on same thing happens.

[Mandrake]

I would check for low voltage or poor earthing.

Low battery voltage when cranking is known to cause the rev counter to ping off the top end of the scale so forcefully that the needle jams there and needs manually flicking back.

Any time you have interaction between different seemingly unrelated systems like the hazard lights and the speedo/tachometer then you should suspect poor earthing at a common earth return - as one circuit draws more current (flashing hazard lights in this case) the "earth" potential rises above zero causing other circuits sharing the same earth return to effectively get less voltage. This can cause all manner of weird and inexplicable symptoms.

I could be wrong but I don't see how plugging the relay in the wrong socket has done any harm, because the pinouts of that type of automotive relay are standardised. More likely you've disturbed a pre-existing fault. What you don't say is whether there was a relay in the blue socket that you removed, or whether it was already empty ?

Do you have a wiring diagram for your model ? The problem with us looking at a picture of your relay box is that with different model variants and production years the relays in the fuse box moved around, so a green relay in the left hand socket might be one relay on your car but a completely different one serving a different purpose on another Xantia. A bit of circuit tracing with a multimeter and schematic diagram is sometimes required to figure out which relay is which.

Silly question maybe, but have you tried disconnecting the battery for half an hour to reset all the ECU's ? If its a Series 2 Xantia and the key light on the dashboard is not lighting then the CPH must not be getting any power. (or is faulty)

No power to the CPH would cause no key light to flash when the ignition is turned on, it would prevent the engine starting (because the engine ECU is not being unlocked by the immobiliser which is in the CPH) and it would also affect the siren, interior (door) lights and central locking which are all controlled by the CPH as well.

The fact that you have other things not working like the front windows suggests that its a lack of power not the CPH itself faulty. (By the way the blower won't work unless the engine is running so don't worry about that one)

You say you've tested all the fuses however have you tested there is voltage to those fuses ? Identify from the owners manual which fuses supply the items that are not working, remove the indicated fuses and use a multimeter in voltage mode to measure between each of the two pins (one at a time) and a good chassis earth, such as the unpainted door strut. (The thing that holds the drivers door open) You'll probably need something like a sewing pin pushed into the slot where the fuse goes to get a connection to your meter's test lead.

Only one of the two pins should show any reading when the fuse is removed but if BOTH show no reading you know there is a problem with the power supply to the fuse.

[xantos]

Thank you for your reply Simon.

I could be wrong but I don't see how plugging the relay in the wrong socket has done any harm, because the pinouts of that type of automotive relay are standardised. More likely you've disturbed a pre-existing fault. What you don't say is whether there was a relay in the blue socket that you removed, or whether it was already empty ?

The blue socket was empty before I just moved the green relay to the blue socket.
Figured out that the green relay was for the fog lights (took it apart and forced it with a bit of wood "on" and the fog lights came on). But when I switch the fog lights on (in the cabin switch) nothing happens.

Tried to test other relays and they all seem to be fine (you can her them clicking when power is applied and there is resistance when they are "on").

Silly question maybe, but have you tried disconnecting the battery for half an hour to reset all the ECU's ?

Yes I did.

Do you have a wiring diagram for your model ?

I have some wiring diagrams but I don't know if they are for my model (from Haynes repair book). Don't know exactly how the read them anyway...

Tried also unpluging the hazard light switch and the lights switch (thinking maybe it's faulty) and no result.
I have also removed all the fuses from the cabin compartment and started the engine with no result.

Seems like I will have to remove the complete dash board appart to try and locate the problem.

Thank you for your help so far.

[CitroJim]

The relay base in question is for the headlight washer timer relay if they are fitted...

It shouldn't have done any harm but my first check would be all fuses, especially the giant fuses. Odd things can happen when some fuses blow...

Sorting out this problem will be tricky unless you use some logical thought on it. The Haynes diagrams are good enough but initially I'd start with the ignition and injection system and work through that one until the engine is running again..

Here are some useful diagrams:

Immobiliser part of the CPH Diagram

Immobiliser part of the CPH Harness Diagram

Immobiliser part of the CPH Layout

Ignition/Injection Circuit

Ignition/Injection Harness Diagram

Ignition/Injection Layout

All are Activa-specific although for an RHD car.

I cannot help you read and understand the diagrams but for a start, the first is the schematic diagram of the system, the second is the physical arrangement of components, connectors and harnesses (looms) whilst the third is the physical location of components, connectors and harnesses on the car. It will be worth taking some time to study how to read a circuit diagram and then study these. They look complex but are very good and elegant when you understand them.

The component codes - e.g. Competent 1320 - the Engine ECU - can be cross-referenced to a list in the Haynes manual.

I hope these help. I have all other diagrams should you need them but I expect these will be enough to set you off.

I wish you good success!

[xantos]

I have measured the pins in the fusebox and these are the results.

I have unplugged the computer, the hydro computer, the LPG computer (yes it runs on LPG ) and the immobiliser and get the same readings so none of them are burnt I would guess.
Are there maybe any hidden fuses or relays somewhere?

Also noticed that the carburetor is heating up (is that ok?) and is giving up humming noise. Also measured it (+ to carburetor and - to battery) and got a result of 0,3V.

[Mandrake]

I can see your problem right away - Fuse 25 (10 amps) has only 3 volts going to it, one of the things it supplies is the "body computer" which is the CPH that I referred to earlier. If this does not get proper power the immobiliser will not function and the engine will not start despite power to the engine ECU. (also affected will be central locking, alarm, interior lights all controlled by the same computer) The "body computer" / CPH should get power all the time even with the engine stopped and car locked as it is listening for the remote key transmitter and monitoring the alarm sensors.

You need to trace the source of power to Fuse 25 in the wiring diagram to see where it comes from, it could be as simple as a broken, burnt or chafed through wire although physically finding it could be difficult.

There are a number of other fuses not receiving power in your list so there could be some significant problems with the wiring harness somewhere in the car, but I would concentrate on the supply to Fuse 25 first as that should get the engine running again when fixed, then tackle any remaining faults.

Your car won't have a carburettor you're probably referring to the idle air control solenoid, and depending on what type that engine uses its normal for them to hum/vibrate and even get a bit warm, so I wouldn't worry about that. The fact that its humming at all tells us the engine ECU is getting power, which is good.

[xantos]

@superloopy

Identify from the owners manual which fuses supply the items that are not working, remove the indicated fuses and use a multimeter in voltage mode to measure between each of the two pins (one at a time) and a good chassis earth, such as the unpainted door strut. (The thing that holds the drivers door open) You'll probably need something like a sewing pin pushed into the slot where the fuse goes to get a connection to your meter's test lead.

Only one of the two pins should show any reading when the fuse is removed but if BOTH show no reading you know there is a problem with the power supply to the fuse.