I had a similar issue on a Skoda 4x4 which turned out to be ABS related, Multiscan seems to be the preferred Fiat diagnostic tool.
Yes ELMs ( hardware)>> Multiscan ( software) , that what I have/use. Think I will have to road test with it connected and see if ABS sensors picking up speed/rotation.
You are fortunate to be able to use the multiscan program, my computer is Linux based so not applicable as Win only. On my Doblo and my daughters Punto Evo I have been able to use my friends Snap On Zeus successfully. On my Skoda 4x4 it threw up most of the messages you had as it affected things like Yaw control when ABS stopped, but as you say no relevant codes showing.
Update, reviewed and cleared codes. Then taken for a spin, even tried the 2 wheels on grass verge trick, but now cleared and working. Dry day sorted the sensors? However now giving the acceleration/yaw sensor as intermittent fault. Have to find where that is and how attached? ( I would have expected it just to be a semiconductor gyro buried in the ECU? like on phones.) See what happens this week.
Maybe some one can advise location better but on my Skoda 4X4 the Yaw sensor was connected to a link on the n/s/f suspension arm but my issue was a fault in the wiring from the n/s/f abs sensor to the abs pump.
My experience says start with battery; low volts removes all of these services. 4x4 TA 63 plate. Next time the issue shows check battery volts if you can , then give it a good charge. Stop Start batteries seem to go off quite quickly. Also check or change brake light switch as it sends when open and closed - this is a common issue.
Also brake light switch; it operates (sends signal) when open and closed... Just because the brake lights are operating doesn't mean the switch is working at rest.
Battery OK volts/charge/capacity wise. But will retest. Start/stop been unavailable for several years, live rural so not a useful function anyway. What do you mean by "as it sends"? what is the actual fault condition please?
I mean the brake light switch has two sets of contacts, it makes a circuit when the pedal is not pressed, so it is normally closed (this I believe informs the computer affecting ABS etc) then this side of the switch breaks a circuit when the pedal is pressed and a second contact closes to put the lights on. Failure of this switch can mess with all the functions you have lost. I do not know what the fault condition is if you are referring to codes. The codes do clear on their own (as I think you have discovered) if it is an intermittent fault; this makes me think it maybe battery volts - issue going away once driven??
Ok understand, but ABS computer says it is a acceleration/yaw fault. If i find it it is testable with a multi-meter. Faults don't self clear just don't re-announce if intermittent ( so to fully clear/check it a multiscan clear errors task.) I suspect the battery finally saying good bye.
Fault codes tell you something is wrong but not necessarily the root cause - just my experience. At risk of repeating myself but I would really be sure of the battery first.
Precisely ( If i am correctly understanding your message), codes are data, but I need knowledge, hence seeking wider experiences.
I think we are on the same page! Let us all know how you get on. Would be very surprised if it is yaw/acceleration sensor, more likely it is complaining about low voltage but doesn't have the vocabulary
)Confused as existing battery looks like a standard wet rather than EFB for stop/start. What type have other got fitted, with what warranty?
