ecu on citroen synergie

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poobear
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ecu on citroen synergie

Post by poobear »

Hi,got a prob with car engine won't run.had get RAC to get me home last WK.he chk the comp witch showed several faults.rail pressure,fuel pressure,egr,and p0221,p0121.not sure what last two are.it went after clear comp but gone at now.bec had prob bef every time it rain heavy he tho ECU gone now.I have a scrap car same yr an col,is it poss to put that ECU in mine as that one runs perfect but got body damage. Mine starts OK but stops,esp if touch throttle. Any ideas or help welcomed. Thanks.
BX
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Re: ecu on citroen synergie

Post by BX »

Language?
sparksie
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Re: ecu on citroen synergie

Post by sparksie »

Sorry, Poobear.
As Northern Mike and BX are both saying in their own way, you're going to have to type it out in whole words, or we won't understand what you're saying and won't be able to help.
I'm considered pretty good at txt (for a fossil!), but I can't make head nor tail of your post.
Please have another go.
Cheers
Sparksie

2000 Xantia 1.9TurboD
poobear
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Re: ecu on citroen synergie

Post by poobear »

Hi.sorry about that,I am old fossil trying to be trendy plus using a cheap tablet and from wales .a friend been round now and diagnosed that the ECU has been damaged by water so need to replace the unit which more than car worth.I have identical car for spares but was told you can't just change the ECU from one vehicle to another is this true? And what else apart from scrapping car can be done? Can't afford new ECU. By the way engine starts but stops as soon as touch throttle and then won't start for a few seconds, I think that's when ECU not speak to rest of engine!!! Any ideas welcome thanks.
Northern_Mike

Re: Re: ecu on citroen synergie

Post by Northern_Mike »

poobear wrote:Hi.sorry about that,I am old fossil trying to be trendy
Don't worry about it. Most of us here are too...


I'm just a grumpy Northern git.
poobear
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Re: ecu on citroen synergie

Post by poobear »

I seem to be having same problems as Charlie ECU not speaking to fuel pump. So is it Charlie's ECU gone?or is it my fuel pump and not ECU that's gone?when we checked ECU it did show car had rail pressure and low fuel pressure. But now of course ECU not speaking with anything. Think of giving it up and looking for another car now. It drives you mad it starts but then stops!!!!!
BX
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Re: ecu on citroen synergie

Post by BX »

The problem where the car starts and then cuts out again as you describe, with fault codes relating to fuel pressure, can usually be one of two problems. The first one is the low pressure pump in the tank being intermittent. This is usually because the commutator is worn ie the pump needs replacing but could be due to wiring or a problem with the relay controlling the pump. Check for brass debris in the fuel filter housing. The second problem is a problem with the fuel pressure regulator mounted on the rear of the high pressure pump. Sometimes due to inadequate filtration the first problem leads to the second. On most of these regulators there is a tiny gauze filter. This can clogs and as the engine speed increases the regulator can no longer drain enough fuel from the high pressure circuit to control the pressure. The engine will cut out but can be restarted after a short period only to repeat the process. The high pressure regulator has been covered on at least two long running threads one to do with not starting and one to do with cutting out. If the regulator has this little filter there are 2 options, replace the regulator with a new one or remove the filter. Cleaning it is impossible and a second hand one can often be a waste of money.Image
If you have an ECU with water damage they often recover when opened and dried out. This is a very common problem on various VW models. If actual damage has occurred then as far as I know on the Synergies you need to swap the ECU along with the immobiliser unit and the transponder chip in the key.
Unless abused physically or electrically the ECU is normally very reliable. Water and being fed voltages or wrong pins are its main enemies. I have never had to change an ECU yet. On several vehicles I have encountered where dealers have diagnosed the ECU to be faulty, the problem has been due to bad or damaged connector.
poobear
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Re: ecu on citroen synergie

Post by poobear »

Thanks bx brilliant reply to my message. Now I want to know how to do the jobs 1)the pump in tank 2)the regulator. I assume that the picture is of the regulator? Shame that you not live near. These modern cars OK when run alright when break down can be a pain. This my 3rd citroen now and the best was was the zantia1.9.till rust won the day, shame that was. I have had the synergie for 4year now this month it's been great apart from when it rained heavy then it would cut off very much the same as its done now but after few minutes would be able to go again with no problem, maybe shock of the dry weather was to much for it.its chucking it down here today so it might go (in my dreams) anyway thanks again for the info will have another go later.
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