Differences in ECU 1.1i and 1.4i

Questions specifically about a Petrol powered Citroen C3 (usually engine or fuel related problems).
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My Name: C3PO_Furio

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Posts: 28
Joined: Tue Aug 11, 2020 11:58 am
Model: C3 2006-2009, Facelift model
Year: 2005 (05)
Engine Size: 1.1
Fuel Type: Petrol
Mileage: 27000
Trim Level: Other
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: LHD (Europe)
Engine name: TU1 (60 PS)
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Hello everyone,
I had to swap all electronics (ECU + BSI) on my vehicle, because of faulty ECU. I have had Johnsons Control J34P ECU.
Now the car is running, configuration is done and no issues are onboard.
The donor car wasn't Citroen C3, it was Peugeot 1007. And the engines were a bit mismatched - donor Peugeot 1007 1.4i and my has 1.1i. If I recall, they are very similar to each other. But I feel that my car behaves a bit different that it used to. I observed three major differences:
1. ECU cuts fuel faster and more aggresive as it did before. This happens while braking with engine.
2. On original ECU while car was moving about 17 km/h on second gear, ECU would automatically put some fuel to engine, now it doesn't do it.
3. When I'm accelerating a bit harder (over 3000 rpm) the fuel consumption is higher as it used to be with original ECU.
Did you guys have ever encountered a situation like this?
I don't remember where exactly, but I found in Lexia some table for engine. It showed some percentage values about sending fuel to engine. I'm sorry about my lack of mechanical knowledge, I don't know the proper terms.
Does anybody can help me with such table for 1.1i ECU (or BSI I don't remeber which device was selected in Lexia)?
I think, that Peugeot 1007 wasn't avaiable with 1.1i engine, so I can't download a software for 1.1i engine in Lexia.
Best regards!
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My Name: Ozvtr

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Posts: 957
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
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So you had a J34P (1.1) and now you are running an S2000pm (1.4)?

I guess it is what it is. They are two different ECU's manufacturers for two different engine sizes. You are talking about two different sets of engineers designing a performance curve for two different size engines. I doubt they talked to each other!
You could try going up to the 1.4l fuel injectors. The fuel trims would be off though.
Check if the 1.1 and 1.4 run the same MAP sensors?
There is not much to try. It's a very simple little engine.
You can't do anything with the ECU but you could get it "chipped".
You cant re-flash the engine ECU's (I doubt the FLASH memory is the same) and you certainly cant do it from a LEXIA.
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My Name: C3PO_Furio

Top Contributor
Posts: 28
Joined: Tue Aug 11, 2020 11:58 am
Model: C3 2006-2009, Facelift model
Year: 2005 (05)
Engine Size: 1.1
Fuel Type: Petrol
Mileage: 27000
Trim Level: Other
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: LHD (Europe)
Engine name: TU1 (60 PS)
Has thanked: 18 times
Been thanked: 8 times

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Hi,
Sorry, I have not been explicit.
I did have JCAE J34P 1.1i ECU
Original JCAE J34P 1.1i ECU
Original JCAE J34P 1.1i ECU
and now I installed Valeo J34P 1.4i ECU
Donor Valeo J34P 1.4i ECU
Donor Valeo J34P 1.4i ECU
. So I replaced JCAE J34P to Valeo J34P.
Car works fine, just those three point that I mentioned before are like warnings to me.
Below you can find Screenshot from Lexia software (New Look Citroen C3). It is shown, that engine 1.1i and 1.4i (TU1A and TU3A respectively) both are using J34P ECU.
Lexia Download table for ECU.
Lexia Download table for ECU.
I was also curious, if anybody knows about mechanical and maybe other differences between those two engines. Both are 8 valve. That's for sure.
Best regards!
User avatar
My Name: Ozvtr

Moderator
Posts: 957
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
Has thanked: 37 times
Been thanked: 256 times

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Hmm, to my knowledge the 'A' versions had carburetors?! The 'JP' versions are fuel injected.

The TU3 has a taller "block". The TU1 has a 69mm stroke and the TU3 has a 77mm stroke. This means the crank shaft will also be different.
The liners are different. The TU1 has 72mm bore. The TU3 has a 75mm bore. So the pistons will be different too.
I think the number of teeth on the water pump is different.
The camshaft cam lobe timing may be different.
There may also be other differences.
User avatar
My Name: Ozvtr

Moderator
Posts: 957
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
Has thanked: 37 times
Been thanked: 256 times

Post

As far as the engine ECU's are concerned, anything is possible given time and enough money!

It might be possible to copy the FLASH memory from the JC ECU to the VALEO ECU. HOWEVER, you have to find someone who can do it and it may cost as much as a used engine ECU and matched BSI (or more)!
It also could be possible to just repair your old engine ECU for about the same cost!
You could read the EEPROM from the new BSI to get the engine ECU PIN code. Then reprogram the EEPROM in your old BSI with that PIN code. That will allow you to use your old BSI and keys. That will solve your BSI (lighting) problems but not your engine ECU problems.

But if you don't want to spend any more money...well you don't have a choice.
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My Name: C3PO_Furio

Top Contributor
Posts: 28
Joined: Tue Aug 11, 2020 11:58 am
Model: C3 2006-2009, Facelift model
Year: 2005 (05)
Engine Size: 1.1
Fuel Type: Petrol
Mileage: 27000
Trim Level: Other
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: LHD (Europe)
Engine name: TU1 (60 PS)
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Been thanked: 8 times

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Hello,
Thank you for your answer.
I have also this screenshot from LEXIA ECU confirmation page.
Lexia ECU confirmation page
Lexia ECU confirmation page
2022-03-01 00_21_50-.png (28.94 KiB) Viewed 20 times
Lexia ECU confirmation page
Lexia ECU confirmation page
2022-03-01 00_21_50-.png (28.94 KiB) Viewed 20 times
Those two images gave me confidence that engines 1.1i TU1A HFX and 1.4i TU3A K6E/KFV are very similar in terms of used ECU.
Original 1.1i and donor 1.4i ECU had even the same HW and SW numbers.
I will try my luck in Peugeot Planet 2000 and after progress I will keep you updated.
But my car works, issues that appeared are minor.
I will upload image of found in Lexia/PP2000 parameters as soon as I will find them. For now thank you very much for your help.
Best regards!
Attachments
List of possible to download ECU from Lexia
List of possible to download ECU from Lexia
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