Fiat Seicento Fault Code

[jiminwatford]

Hi,

I'm trying to help someone fix an error code / running issue

The car is a Fiat Seicento with multipoint 1108cc FIRE engine

The car is rough at idle and shows code P0505 which is the Idle Air Control Valve Circuit

He has tried two more throttle body units which show the same error

He has tried another ecu / immobiliser / key and the engine wouldn't start and showed code U1600 which is immobiliser fault

I have supplied an alternative ecu set and the same U1600 code comes up

I don't know if there are any other things to try?

The battery was disconnected whilst the ECUs were swapped. I think he is going to reconnect the replacment setup and leave it before trying to start, to see if the car gets used to ?!?!

Hopefully someone has some info on these ecu systems (

Thanks
James

[bortaf]

Has he cleaned any of the IACVs? or just fitted 2nd hand units and hoped it would work?
TBH mate a new IACV for those is under £20 so i'd simply fit a new one or clean the existing one first and test the wiring? did he clear the fault code ? if not clear the code and then go for a drive it will take the ECU a few mile/mins to re learn the perameters of the new actuator/throttle body.
TBH swapping the ECU for a simple idle valve problem is a bit over the top IMHO, they allways play up no matter the vehical, i've had all sorts in for idle valve clean/change and swapping I'm S/H parts is not as simple as it was 20 years ago, parts need to learn to work together and some (as you have found) simply wont swap in/out that easly

[jiminwatford]

Thanks for the info

I'm not with him so i will pass it on

James