Citroen C3 2006 Rough idle and SERV light on

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Moyhentaja
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Re: Citroen C3 2006 Rough idle and SERV light on

Unread post by Moyhentaja »

New battery and new altenator! Ecu pins looking brand new. Wigling the wiring loom, connectors & passthrews does not bring fault codes. I will be bringing rthe car in to the local citoren guru to see if they have the right tools and knowledge to diagnose.. They have no lexia tools however. I have also requested used throttle body and throttle pedal from the wreckers to see if that makes any difference. Bet it wont.
ozvtr
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Re: Citroen C3 2006 Rough idle and SERV light on

Unread post by ozvtr »

No disrespect, but new does not mean good!
I would then ask the question; why are the battery and alternator new and when were they replaced? Were they replaced because the alternator died and took out the battery? Were they replaced BECAUSE of this fault? Were they replaced just before this fault?
Engine ECU is still a suspect if you eliminate everything else.
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Moyhentaja
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Re: Citroen C3 2006 Rough idle and SERV light on

Unread post by Moyhentaja »

ozvtr wrote: 30 Apr 2026, 02:39 No disrespect, but new does not mean good!
I would then ask the question; why are the battery and alternator new and when were they replaced? Were they replaced because the alternator died and took out the battery? Were they replaced BECAUSE of this fault? Were they replaced just before this fault?
Engine ECU is still a suspect if you eliminate everything else.
I dont know, just bought the car from the auction. I am hoping its not ecu fault
ozvtr
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Re: Citroen C3 2006 Rough idle and SERV light on

Unread post by ozvtr »

Moyhentaja wrote: 30 Apr 2026, 05:55 I dont know, just bought the car from the auction. I am hoping its not ecu fault
OH, I see. You should have told us that in the first place. We could have moved along a bit quicker.

Can I give you a piece of advice on buying cars that don't run? Particularly auction vehicles.
Expect the worst and prepare for long journey to recovery! I do not recommend it for the "feint-of-heart".

I have gone through this process a number of times (see my bio to the left) and I can tell you the cars are rarely in serviceable condition and typically have lots of hidden faults.

HOWEVER, I don't know you and you might "flip" cars for a living. In which case you already know what I'm saying.

If you wish, I can give you a list of things I typically find wrong with the 2002-2010 1.4 (KFV) C3's.

While I'm very familiar with the C3 I do not consider myself an "expert". Most of the C3's sold here in Australia are petrol KFV engined variants. So no dual fuel and no LPG versions. I have not seen a Johnson Controls ENGINE ECU. However I am familiar with the TU5JP4 (NFU) 1.6i engine C3 (typically SENSODRIVE) and that runs a BOSCH ME7.4.4 ECU. There are some 1.6i and some diesels, but I am unfamiliar with the diesels at all!

So my question to anyone would be; do Johnson Controls do an engine ECU for the KFV engine? I can only find VALEO and SAGEM. So is the poster looking at the BSM? Happy to be "educated" on this matter. :-D

Once again, no disrespect to anyone. Just trying to be helpful.
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mickthemaverick
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Re: Citroen C3 2006 Rough idle and SERV light on

Unread post by mickthemaverick »

I have deleted the last post which used unacceptable language and a personal insult to another member. Further such posts may result in a ban from the forum !
I used to be indecisive, now I'm not so sure!
I used to ride on two wheels, but now I need all four!
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Moyhentaja
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Re: Citroen C3 2006 Rough idle and SERV light on

Unread post by Moyhentaja »

ozvtr wrote: 01 May 2026, 04:50
Moyhentaja wrote: 30 Apr 2026, 05:55 I dont know, just bought the car from the auction. I am hoping its not ecu fault
OH, I see. You should have told us that in the first place. We could have moved along a bit quicker.

Can I give you a piece of advice on buying cars that don't run? Particularly auction vehicles.
Expect the worst and prepare for long journey to recovery! I do not recommend it for the "feint-of-heart".

I have gone through this process a number of times (see my bio to the left) and I can tell you the cars are rarely in serviceable condition and typically have lots of hidden faults.

HOWEVER, I don't know you and you might "flip" cars for a living. In which case you already know what I'm saying.

If you wish, I can give you a list of things I typically find wrong with the 2002-2010 1.4 (KFV) C3's.

While I'm very familiar with the C3 I do not consider myself an "expert". Most of the C3's sold here in Australia are petrol KFV engined variants. So no dual fuel and no LPG versions. I have not seen a Johnson Controls ENGINE ECU. However I am familiar with the TU5JP4 (NFU) 1.6i engine C3 (typically SENSODRIVE) and that runs a BOSCH ME7.4.4 ECU. There are some 1.6i and some diesels, but I am unfamiliar with the diesels at all!

So my question to anyone would be; do Johnson Controls do an engine ECU for the KFV engine? I can only find VALEO and SAGEM. So is the poster looking at the BSM? Happy to be "educated" on this matter. :-D

Once again, no disrespect to anyone. Just trying to be helpful.
Yeah, car was bought from auction in running condition, no issues. 90k km's on clock, 1 owner, immaculate condition and it really is. I've attached a picture of the ecu for reference.

Update:

I have completed the aforementioned bosch specific "calibration" values EEPROM programming sequence. The ECU infact does the calibration run by driving the throttle valve to its endpoints with that procedure. The car has now worked fine for 2 days, no problems. However when the serv light was on and radio screens says "Engine Manangment Failure" the OBD comms port reader cant find any fault codes. The car just wont respond to the thorttle pedal command and it is running poorly. The Throttle valve does not recieve power at this time when the fault is active.
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PaulC5
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Re: Citroen C3 2006 Rough idle and SERV light on

Unread post by PaulC5 »

I hope nobody has been criticising ozvtr, he is one of the most helpful people on here and has spent many an hour trying to sort other's problems.
ozvtr
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Re: Citroen C3 2006 Rough idle and SERV light on

Unread post by ozvtr »

Moyhentaja wrote: 01 May 2026, 08:42 The car has now worked fine for 2 days, no problems.
Lets keep our fingers crossed.
Moyhentaja wrote: 01 May 2026, 08:42 However when the serv light was on and radio screens says "Engine Manangment Failure" the OBD comms port reader cant find any fault codes. The car just wont respond to the thorttle pedal command and it is running poorly. The Throttle valve does not recieve power at this time when the fault is active.
So the P0122 & P2122 codes disappeared? That's disconcerting. There are a thousand things that can cause the engine to go into "limp mode". I would assume the P0122 & P2122 codes are still there but the reader is not getting data, for one reason or another. I would hope it's not a new fault.

IIRC if there any problems with the engine controls after a drive cycle has started, the engine goes into limp mode, but the vehicle still moves. However, if a failure is detected at startup, the engine will not respond to the accelerator.
ozvtr
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Re: Citroen C3 2006 Rough idle and SERV light on

Unread post by ozvtr »

PaulC5 wrote: 01 May 2026, 11:35 I hope nobody has been criticising ozvtr, he is one of the most helpful people on here and has spent many an hour trying to sort other's problems.
Thank you. I'm only trying to help. I apologize profusely if I have offended anyone, in any way.