hdi ecu

[taffy]

hi....
i suspect my ecu is faulty as im getting 9 volts from the fps signal wire and it sounds 98% like i need a new one
anyone got any expeirence doing this?
can i get any same ecu as in edc15c2 and get it unlocked or does it have to be serial number?
also does it matter if it was a pug or citroen?
thanks in advance

[miked]

fps as in fuel pressure sensor? Is the 9 Volts measured the signal from the sensor to the ecu? I'm happy to be corrected but I'd guess 9 volts is way too high. Why are you sure you need a new ECU?

[taffy]

yea 9 volt coming from the ecu signal wire....when it should be supplied by the fps at atleast 1 volt at cranking...got good earth and 5v power but signal 9 volts...got p0190 will not clear and p00cc,just wondered what the deal was with atleast <just trying> another ecu?

[citroenxm]

Urrrmmmm... Firstly its about 100£ to unlock a HDi ECU...

Secondly, if you want to try another Second hand one, you WILL need the Body computer matching the supplied one!!

After then, you then need to match YOUR key to the ECU/Body computer, this you WILL need a lexia to do.

Ive got a matched ECU and body computer here somewhere, but as said you need it matching to your key.

Im not convinced its an ECU problem They are rather reliable. It could though be a harness issue on the car some where!

[miked]

yea 9 volt coming from the ecu signal wire....when it should be supplied by the fps at atleast 1 volt at cranking...got good earth and 5v power but signal 9 volts...got p0190 will not clear and p00cc,just wondered what the deal was with atleast <just trying> another ecu?

OK, I realised after I posted that you already have a long thread on the problem. I did follow that thread at the time but didn't think I could add much to the advice you were given.
Are you saying that the supply to the sensor is 5V, but that you are getting 9V back to the ECU? If so I would say something in the wiring harness is wrong. I'm not a mechanic or an auto-electrician (although years ago I did an electronics degree) but I would find it strange if an analogue input to the ECU suddenly started supplying 9 volts. Is there any way you can isolate the signal wire at the ECU end to make sure that the sensor and wiring are OK?

[taffy]

yea ive checked contunuity of all the wires all are good..conected or disconected fps, still gives a 9v signal coming OUT of the ecu...the signal wire for the fps is supposed to see 1v IN to the ecu...as soon as key on 9.14v is there and p0190 which wont clear atall
pretty gutted now really i need this car running soon even thou it hasnt been running for couple of months my mrs is due to drop in feb hence im desperate for an answer now...read for hours and days on google trying to find answers but nothing quite the same as my problem...yea sorry i have a good 5v to pin 3,earth at pin 1 and 9v at pin 2
thanks for replys guys

[BX]

Do not jump to hasty conclusions. At the moment i do not have a bosch hdi to check. I strongly suspect that the 9V might be a stray voltage. Check the resistances between the pins on the frp sensor. Check the continuity of the wire end to end if you haven't already done so. Sometimes a signal wire left open circuit may have a voltage on it. Earth this wire through a resistor of say 220 ohms and measure the voltage on the wire then. Of course its possible the ECU is faulty but I believe it to be unlikely. I have seen many ECUs, pwm,s, BSIs and body computers changed even though they were not faulty. The disease of "change the unit" comes from warranty work. If I get a chance I will take some measurements from the next 2.0 8 valve with Bosch injection I lay hands on.

[taffy]

thanks im trying not too but all the checks ive done and parts ive replaced and all along it could be a failed ecu...well ive taken the loom pretty much apart and chased wires from this and that sensor getting voltages and everything seems fine apart from this 9v...ive replaced hp pump,injectors,fps,fpr,cam sensor,battery and cleaned up all earths i can find...run the lp line to hp pump via inline filter to rule out filter housing..horrible thing is i thought my battery was good whilst doing these tests and replacements and ive recently bought a new one and my old one was knackered in comparrison..
that would be great mate if u could get some readings cause maybe on this ecu the fps might work different...as ive heard of ppl with a broke fps disconecting it and the ecu will default to set parrimiters and allow it to start..where as older ones dont
thanks for the ideas

[citroenxm]

Taffy.. no mention of crank senor is your list of changes... have you changed it????

[taffy]

no crank sensor is fine mate..if i disconect it i get no rpm on the clocks..when i connect it i get rpm reading i have cleaned it thou

[taffy]

http://www.406oc.co.uk/viewtopic.php?f=3&t=20455" onclick="window.open(this.href);return false;
good link here for ecu pin outs

[BX]

This is the pin out of the 3 plug Bosch ECU used on the 2.0 HDI 8 valve. The pic in the top left of the page is from the single plug ecu. I can upload that pin out if anyone wants it
http://s630.photobucket.com/user/tullyc ... 1.jpg.html

[taffy]

yea thats handy good one
well just bought a lexia 3...just gota wait for it to come and see what that says...
anybody know a link to a good guide on the lexia operation?
many thanks

[taffy]

also while researching the ecu i found you can buy the software for a tenner to decode ur ecu...wont repair it but it would be handy software...universal decoder v3 i think it was...just need appropriate cable

[Hell Razor5543]

Taffy, there is no guide for the Lexia. As it is a copy of official PSA kit (both hardware and software), and PSA train their staff on how to use the official kit, the best that you can do is to try it out and learn from it (as well as read through the forum). Mainly work your way through it to see what it shows you, but (until you are ready to make changes) don't do anything such as updating ECUs, otherwise you might brick it. Just get it to show you what is going on.

If you have the 3 discs for Citroen manuals, install them before you install the Lexia software. I have installed these discs on my main PC, but it took 5 hours to install (mainly as disc 3 has thousands of diagrams, and took 3 hours), and my PC is no slouch.