VN05N removal (she's alive!)

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

HDI
Posts: 1468
Joined: 22 Sep 2009, 15:46
Location: West Mids
My Cars:
x 7

Post by HDI »

Obsolete electronics are going to be the deciding factor to scrap modern vehicles and the manufacturers love that !!
However , if there is enough demand , substitute electronic units could be designed to replace the originals. After all , when tuning cars , it is almost a given that an upgraded new , reprogrammable engine management ECU will be fitted. This is superior to the original in every case and the non race types are not really expensive in relation to their performance and facilities.
Problem is , that cars like Citroens are unlikely to provide an adequate demand for substitute electronics , unless an owners club commissions them.
Now using '00 Xantia LX HDI, pov spec :(
My past Citroens :-
'00 Xantia SX HDI, now dead due to accident :(
'99 Xantia HDI 110 Exclusive, RIP :(
'97 Xantia TD SX
'96 Xantia TD LX
'96 ZX TD
'89 BX TD
'88 AX GT
'79 CX2400 Pallas (scrapped :( )
& a couple of Peugeots !
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Post by DickieG »

admiral51 wrote:Sorry guys just been up the scrappy and the car has gone they crushed it along with a S1 TD :twisted: :evil:

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 :wink:

Colin
Blast I was just about to ask you where the yard was :evil: BTW the Hydractive ECU is located within a black box behind the O/S headlight
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
Peter.N.
Moderating Team
Posts: 11563
Joined: 02 Apr 2005, 16:11
Location: Charmouth,Dorset
My Cars: Currently:

C5 X7 VTR + Satnav Hdi estate Silver
C5 X7 VTR + Hdi Estate 2008 Red

In the past: 3, CX td Safaris and about 7, XM td estates. Lovely cars.
x 1199

Post by Peter.N. »

John

Are the Xantia ECUs the same as the XMs?

Peter
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Post by DickieG »

Peter.N. wrote:Are the Xantia ECUs the same as the XMs?
They are when new until they are programmed for either XM or Xantia.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
xmexclusive
Posts: 419
Joined: 18 Dec 2008, 22:50
Location:
My Cars:

Post by xmexclusive »

Hi Peter

All suspension ECU's of H1 to H4 coding are model specific, the onboard Microcontroller is factory programmed using a EPROM programmer most likely before the chip is soldered to the PCB. Each variant has a seperate Citroen part number.
It is only H5 onwards suspension ECU's that are made as a blank universal unit. These have the later EEPROM Microcontroller which can be written to electrically to store a program for a specific car. Because of the type of Microcontroller chosen (write once) it can only be programmed a single time. The LEXIA can do this programming on a new blank ECU but not change the stored program on a secondhand unit.
Sadly there were very few H5 ECU's used as the blank Microcontrollers can be bought though the soldering job of replacement of a 64 pin device is not for the faint hearted.

John
Xmexclusive
Peter.N.
Moderating Team
Posts: 11563
Joined: 02 Apr 2005, 16:11
Location: Charmouth,Dorset
My Cars: Currently:

C5 X7 VTR + Satnav Hdi estate Silver
C5 X7 VTR + Hdi Estate 2008 Red

In the past: 3, CX td Safaris and about 7, XM td estates. Lovely cars.
x 1199

Post by Peter.N. »

Thanks John.

I gave up that soldering 64 pin ICs lark when I retired. Hopefully then if they are not reprogrammable they are less likely to be corrupted.

Peter
deian
Posts: 1729
Joined: 26 Feb 2006, 10:53
Location:
My Cars:

Post by deian »

hi all,

right back to square one, whether that is good or bad, i have with me here paul's hydractive ecu, we put it on and it didn't work, no life at all, anyway, paul said see what you can do... so i took it and said i would open it up and have a look!

it is "100% IDENTICAL", the heat corrosion of the BUZ11 is EXACTLY the same, the hot (failed) VN05N is EXACTLY the same colour, same transistor too, it's always the top-est one, the one closest to the connector, now if I/we can work out which electrovalve that drives then maybe we can work out WHY it fails, surely it can't be a diode fail on both, it seems like one, and the same one. Even the blobs of glue are exactly the same size and shape.

Anyway, I will go back and carry on playing spot the difference, and decide whether to solder one transistor this time, VEEERRRY carefully using the weller iron this time.

Wish me luck!
User avatar
CitroJim
A very naughty boy
Posts: 49534
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6163
Contact:

Post by CitroJim »

deian wrote: Wish me luck!
Luck wished Dei :D

Must be something in the Anglesea air that's killing the ECUs :lol: :lol:

I don't know if this will help determine which VN05 does what but here's a typical circuit of the hydractive system.

The electrovalves are items 7716 and 7717, 7716 being the front one...
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
Peter.N.
Moderating Team
Posts: 11563
Joined: 02 Apr 2005, 16:11
Location: Charmouth,Dorset
My Cars: Currently:

C5 X7 VTR + Satnav Hdi estate Silver
C5 X7 VTR + Hdi Estate 2008 Red

In the past: 3, CX td Safaris and about 7, XM td estates. Lovely cars.
x 1199

Post by Peter.N. »

Have you checked to make sure the have the permamant 12v supply on the ECU?

Peter
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Post by DickieG »

deian wrote:it is "100% IDENTICAL", the heat corrosion of the BUZ11 is EXACTLY the same, the hot (failed) VN05N is EXACTLY the same colour, same transistor too, it's always the top-est one, the one closest to the connector, now if I/we can work out which electrovalve that drives then maybe we can work out WHY it fails, surely it can't be a diode fail on both, it seems like one, and the same one. Even the blobs of glue are exactly the same size and shape.
And for number three,

Image
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
xmexclusive
Posts: 419
Joined: 18 Dec 2008, 22:50
Location:
My Cars:

Post by xmexclusive »

On the PCB photo that Dien originally put up the VN05N nearest the white connector drives the front electrovalve via pin 1 of the connector. The VN05N furthest away from the connector drives the rear electrovalve via pin 2 of the connector.
Have done a bit more circuit tracing on the scrap ECU that I have here.
There does not seem to be the direct connection that I expected between the BUZ11 and the VN05N electrovalve drivers.
The inputs (pin2) of the VN05N's are driven directly each by seperate output lines running from the TMS3700056 Microcontroller. This suggests that BUZ11 burn out is not directly related to VN05N burn out. If this was the current feed the fine circuit tracks and the Microcontroller internals would burn up long before the sort of damage we are seeing could be inflicted on the VN05N's and the BUZ11.
I have now also traced the output of the third VN05N. This goes to pin 9 of the Black plug. Can anyone confirm that this is the pin that drives the third electrovalve on an Xantia Activa?

John
Last edited by xmexclusive on 02 Jan 2010, 22:23, edited 2 times in total.
Xmexclusive
deian
Posts: 1729
Joined: 26 Feb 2006, 10:53
Location:
My Cars:

Post by deian »

thanks for the wiring diagram jim,

so richard has a top one damaged too, i rekcon it could be the back electrovalve, the frying could be due to the distance the sine wave travels down the cable from front to the back of the car and may get interference from other sources along the way, hence the transistor working harder?

i'm doing just the one this time, and i am puttins less solder in it, and no drilling the holes clean, i will try to reuse the existing solder
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Post by DickieG »

deian wrote:no drilling the holes clean, i will try to reuse the existing solder
That's what I did.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
deian
Posts: 1729
Joined: 26 Feb 2006, 10:53
Location:
My Cars:

Post by deian »

on the right track then...
Peter.N.
Moderating Team
Posts: 11563
Joined: 02 Apr 2005, 16:11
Location: Charmouth,Dorset
My Cars: Currently:

C5 X7 VTR + Satnav Hdi estate Silver
C5 X7 VTR + Hdi Estate 2008 Red

In the past: 3, CX td Safaris and about 7, XM td estates. Lovely cars.
x 1199

Post by Peter.N. »

Hi Deian

You really need fresh solder because the flux will have evaporated, you need a hot, clean iron, place it it on the connection and either remove the solder with a solder sucker or move the board rapidly so that it flies off. When resoldering, apply the heat to the joint not the solder, when hot apply the solder and it should run neatly into the joint with no overspill.

Its important that the metal you are soldering to is at the melting temperature of the solder before you apply it, dont worry about the heat on the components, they are designed to stand it. The hotter and cleaner the iron, the less time you need it in contact to bring the temperature up.

Peter
Post Reply