High rpm on idle (P1676, P1675, P1674)

Hello,
This topic on this site and few others existed. Yet I didn't find an answer to my problem. Could someone please help me with it?
My car is 2005 C3 1.1 (facelift model), it drives well with one exception - when turned on it revs up to 2000 rpm and stays there until drive (so gear in and a bit of throttle).
After engine warms up a bit (about 3km of city drive) the problem is as follows:
After changing to neutral on rpm higher than ~1750 it will go up to 2000 rpm and stay there until car is completely stopped.
After changing to neutral on rpm lower than ~1250 it will go down to 1000 rpm and stay there.'
Middle zone ~1250-1750 rpm is a lottery sometimes it goes up and sometimes it does not.
It started over a month ago and in this period of time two mechanics has had this car to diagnose.
One is a local mechanic, he thought it might be throttle body and swapped it to another used one. Problem remained unsolved – normal idle rpm was higher – about 2500-3000 rpm.
After two visits he said I should visit an electro-mechanic, he diagnosed car whole day and found a problem and a weird behaviour – after unplugging alternator plug nothing changes.
On Lexia it shows, that alternator is missing, voltage is fine, car drives etc.
I bought Lexia for my own and tried to dig a bit deeper and my question is: Is it possible, that alternator type is wrong? What is correct type of alternator for Citroen C3 1.1?
When ignition is switched on (without turning engine on) there is a silent noise from throttle body – feep (peep or a squeak). It stays after ignition is turned off. Is it possible that this is related?
In attachments you can find screenshots with specific Lexia data. Filename corresponds to menu of Lexia system.
With best regards!

Hi

You have P1676 fault logged.

Use lexia to suggest a solution and checks to do for P1676 or P1675 or P1674, or all of them, they are all connected.

You are more likely to have a wiring fault/failing alternator for an intermittent fault than a misconfigured BSM/ECU.

I don't know what setting you should have, but don't change them and see what lexia can tell you to do next.

Model: C3 2006-2009, Facelift model
Year: 2005 (05)
Engine Size: 1.1
Fuel Type: Petrol
Mileage: 15000
Trim Level: Other
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: LHD (Europe)
Engine name: EB0 PureTech 3-Cylinder (68 PS)

You have a 3 cylinder engine listed in your car bio, its a 2005 but shown as a facelift.

Please check and select the correct information for your actual car here - car bio

From what I can figure out The "piloted" alternator is a regenerative alternator.

Unless there is something fancy about your C3 I don't see why it would have a regenerative alternator.

I gather it should be a "standard" alternator, class 8+ or 9.

I don't have an answer to the high idle revs at this time. You can try pushing the throttle peddle all the way to the floor and turn the ignition to on (not start). wait 5 seconds and then release the peddle, wait 5 seconds turn the ignition off.

The squealing coming from the throttle body is normal.

Hello,
You suggested to do:

C3driver52 wrote: ↑Wed Nov 24, 2021 9:58 pm Use lexia to suggest a solution and checks to do for P1676 or P1675 or P1674, or all of them, they are all connected.

How to aquire solution and checks from Lexia?
Best regards!

C3driver52 wrote: ↑Wed Nov 24, 2021 10:02 pm

Model: C3 2006-2009, Facelift model
Year: 2005 (05)
Engine Size: 1.1
Fuel Type: Petrol
Mileage: 15000
Trim Level: Other
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: LHD (Europe)
Engine name: EB0 PureTech 3-Cylinder (68 PS)

You have a 3 cylinder engine listed in your car bio, its a 2005 but shown as a facelift.

Please check and select the correct information for your actual car here - car bio

Hi,
Thank for pointing my mistake, I corrected that information. I have 1.1 liter TU1A engine.
Best regards!

odoedel wrote: ↑Mon Nov 29, 2021 8:17 pm Hello,
You suggested to do:

C3driver52 wrote: ↑Wed Nov 24, 2021 9:58 pm Use lexia to suggest a solution and checks to do for P1676 or P1675 or P1674, or all of them, they are all connected.

How to aquire solution and checks from Lexia?
Best regards!

F5 when you have the fault on the lexia screen.

Ozvtr wrote: ↑Thu Nov 25, 2021 9:26 am From what I can figure out The "piloted" alternator is a regenerative alternator.

Unless there is something fancy about your C3 I don't see why it would have a regenerative alternator.

I gather it should be a "standard" alternator, class 8+ or 9.

I don't have an answer to the high idle revs at this time. You can try pushing the throttle peddle all the way to the floor and turn the ignition to on (not start). wait 5 seconds and then release the peddle, wait 5 seconds turn the ignition off.

The squealing coming from the throttle body is normal.

Hello,
Thank you for your help.
I tried to reset acceleration pedal, but it didn't help.
Thank you form information about throttle body squeal.
I changed alternator type from "piloted" to "standard", but with no success.
I think it may be related to the fact that in ECU it is still "Not used (controlled alternator)".
How to change alternator type in ECU? By ECU coding from VIN?
Lexia showed new errors P0121 and P1161...
I didn't do auto adaptation (I will conduct that procedure later this week).
Best regards!

Arfur Dent wrote: ↑Mon Nov 29, 2021 8:22 pm

odoedel wrote: ↑Mon Nov 29, 2021 8:17 pm Hello,
You suggested to do:

C3driver52 wrote: ↑Wed Nov 24, 2021 9:58 pm Use lexia to suggest a solution and checks to do for P1676 or P1675 or P1674, or all of them, they are all connected.

How to aquire solution and checks from Lexia?
Best regards!

F5 when you have the fault on the lexia screen.
lexia-diagnostics.png

Hello,
Thanks, but as visible on my later screenshots F5 wasn't avaiable. Is it visible in only one menu?
Best regards!

Hello,
Thanks, but as visible on my later screenshots F5 wasn't avaiable. Is it visible in only one menu?
Best regards!

It shows on the screen in my image.

I don't know what's up with your lexia but you tell us it is a 2005 model, but your lexia shows it as a 'new look Citroen C3', which the 2005 model is definitely not. I would suggest identifying the vehicle correctly for lexia to get the best chance to communicate with it.

To get lexia to work you should allow it to identify the vehicle by the VIN it discovers then confirm it matches the expected VIN (i've never seen it not correct).