Fast Regulator Tick in Soft Mode (Now Solved!)

citrov6 · Post by **citrov6** » 22 Aug 2009, 01:30

impressively deduced. can someone post a link to the diode mod, just did a quick search with a few things about the ecu coming up. 3rd time i've heard this mentioned now which is sparking my curiosity

Post by **CitroJim** » 22 Aug 2009, 10:10

citrov6 wrote:can someone post a link to the diode mod

Here you are sir, written by the suspension god himself

Hydractive Diode Mod

citrov6 · Post by **citrov6** » 22 Aug 2009, 10:39

thanks Jim , your a gent

vince · Post by **vince** » 22 Aug 2009, 12:05

It will indeed be interesting to see what the problem is traced to as mine shares the same problem for now.

I do also have a spare ECU as discovered at the DSM rally so will keep that incase its needed

Jim, does the back of yours drop shortly after starting then rise again and then behave normally? ...thats the main effect of my problem

red_dwarfers · Post by **red_dwarfers** » 22 Aug 2009, 14:39

vince wrote:It will indeed be interesting to see what the problem is traced to as mine shares the same problem for now.

I do also have a spare ECU as discovered at the DSM rally so will keep that incase its needed

Jim, does the back of yours drop shortly after starting then rise again and then behave normally? ...thats the main effect of my problem

Mine did that and all was well after replacing the rear accumulator, im guessing the problem was something to do with a lack of pressure after the antisink valve opened on startup....I may be barking up the wrong tree though and it was coincidence

EDIT: Wasn't that extra ECU you found from an XM?

DickieG · Post by **DickieG** » 22 Aug 2009, 16:10

Jim, IIRC isn't there waveform shown in the Xantia suspension manual?

vince · Post by **vince** » 22 Aug 2009, 18:05

red_dwarfers wrote:
vince wrote:It will indeed be interesting to see what the problem is traced to as mine shares the same problem for now.

I do also have a spare ECU as discovered at the DSM rally so will keep that incase its needed

Jim, does the back of yours drop shortly after starting then rise again and then behave normally? ...thats the main effect of my problem
Mine did that and all was well after replacing the rear accumulator, im guessing the problem was something to do with a lack of pressure after the antisink valve opened on startup....I may be barking up the wrong tree though and it was coincidence

EDIT: Wasn't that extra ECU you found from an XM?

Yes it was but the car ran fine on it for almost 2 years until it was discovered

The rear accumulator you say......might be worth changing it anyway as my rear spheres all need doing i reckon......Hmmmm

Isnt that the rear centre sphere and the one thats harder to change?

xmexclusive · Post by **xmexclusive** » 22 Aug 2009, 18:37

Hi Jim

I have a copy of the VN05N data sheet.
There is one very interesting feature which is the device is self protecting and shuts down on junction thermal overload (140degC and restarts as soon a it cools to 125degC). Thermal sensor is on board the junction and claimed to be virtually instantaneous. So all those suspension circuit boards with burn marks around the VN05N's are not reaL. Seriously though device auto shut down/restart could make fault finding a real sod.
Repeated triangular waves from the output instead of a good square wave are indicative of the thermal shutdown cutting in. The data sheet example shows this happening 3 times within the length of a single square wave element so the cut-in/cut-out heating cooling cycle must be very fast indeed.
The other little gem is that pin 4 of the device is a status line to tell you in combination with the input/output what the device is doing or failing to do. Pin 4 should be high in normal operation. Pin 4 low indicates a fault state so if you monitor pin 4 on the scope as well as pin 5 the output you should see pin 4 go low with each thermal cut out. I wonder what the electrovalve does during shut down?
The spec seems to indicate that the device can drive a resistive load without the need for protective diodes.
Description is:
The VN05N is a monolithic device made using STMicroelectronics VIPower technology, intended for driving resistive or inductive loads with one side grounded. Built-in thermal shutdown protects the chip from over temperature and short circuit. The input control is 5V logic level compatible. The open drain diagnostic output indicates open circuit (no load) and over temperature status.

John

Post by **CitroJim** » 22 Aug 2009, 22:06

John, thanks, that's incredibly useful information

Vince, the rear centre sphere is the one and is not harder to change, just different. It's the sphere right in the centre, facing forwards, just in front of the antisink valve. Don't confuse it with the hydractive centre sphere which is toward the offside and dangles down at a 45 degree angle.

The technique for changing it is this: Undo the pipe union a few turns with a 9mm spanner uniil the union is a bit loose. Hold the 9mm spanner on the union nut whilst using a Pleiades tool or similar to staart to undo the sphere from its mounting bracket. It's important to loosen the union nut and hold it to avoid damage to the hydraulic pipe.

Whilst holding the 9mm spanner on the union nut, undo the sphere. When it is nearly all undone, use your finger to pull the pipe out of the end of it.

Replacement is a reversal but do use a new seal on the hydraulic pipe.

red_dwarfers · Post by **red_dwarfers** » 22 Aug 2009, 22:14

CitroJim wrote: Replacement is a reversal but do use a new seal on the hydraulic pipe.

And make sure its a 4.5mm replacement seal rather than the more common 3.5mm one

xmexclusive · Post by **xmexclusive** » 22 Aug 2009, 23:05

Jim

Cannot remember where the VN05N spec sheet came from and cannot scan it in so if you PM me with your address I will pop a photocopy of the spec in the post.

John

vince · Post by **vince** » 23 Aug 2009, 09:03

Thanks guys,

All i need to get hold of is a sphere tool. I know ebay do them, Might see if i can source one through work perhaps or through Pleides.

I take it the 4.5mm seal is measured through the internal diameter of the hole. Is it the small tube shaped one or an O ring design?

Post by **CitroJim** » 23 Aug 2009, 09:07

Hi Vince,

Get a Pleiades one. If you're in the Xantia game long-term, especially with a VSX, it'll pay for itself over and over again, especially when attacking hydractive centres!

Yes, the seal is the tubular one. You'll see the old one will be stuck inside the old AS sphere when you remove it. Dig it out with tweezers. Your SWMBO will appreciate you using her tweezers for this as the residual LHM on them will condition her eyebrows next time she plucks them....

Post by **CitroJim** » 23 Aug 2009, 09:08

xmexclusive wrote:Jim

Cannot remember where the VN05N spec sheet came from and cannot scan it in so if you PM me with your address I will pop a photocopy of the spec in the post.

John

John, you're a star

If I cannot download one, I'll be in touch. Many thanks

Post by **xantia_v6** » 23 Aug 2009, 09:14

Try this

BTW, I just have a feeling that there is a big red herring in the information we have so far... but I can't put my finger on it. I think it would be good to find a way to confirm that the HA valve leak rate is actually caused by the shorter waveform.

Ah... Jim, you have all the gear you need... Connect the activa ECU to the V6 electorvalves, (leaving the ECU in the activa, check the waveform and the tick rate.