Hi All,


Please help me


On my fiat 500 1.2l Lounge (59 plate) my amber engine light, amber stop/start light and an amber triangle with an exclamation mark inside have come on on my dashboard.


I took my car to my mechanic who said the fault code was P0555, he cleared this code, but yesterday the lights came back on again.


I obviously don't want to take it back to my mechanic as he will just clear the code again...and charge me for it!!! Does anyone know of this code and what the problem could be with my car?
It drives perfectly fine, but obviously I don't want to be driving it around and possibly causing more damage.


Any help would be greatly appreciated.


Many thanks
Hannah

How do the brakes feel ok or heavier than normal, a quick Google flags up brake boost pressure sensor open circuit (brake servo) The suggestion is the sensor maybe disconnected or lost its earth and should be near the servo possibly connected via a hose .

Mine just done this today. Had done it a couple of weeks ago so I bench charged the battery. Thought it had gone but when I started the car this evening I had the same warning lights. I will plug in multi ECU scan tomorrow, see if a code comes up.

No broken hatch wiring on mine. I've attached MultiECUscan but I can't get it to connect to the engine ECU. I have ordered a new modified Elm327 cable and a new battery.

Did this sort the problem? My lights went off for a few months (they went off on their own) but they are back on again now.
Still dont feel a difference in the car, but thinking i need to get it seen to.

Did the new battery and cable work?

many thanks
Hannah

There is another thread on this for my problem. It turned out to be the ECU. I changed the throttle body and pedal but it kept coming back. Had to buy a second hand ECU and had it virginised.

Hi you all, I fixed the p0555 error yesterday on a '14 reg fiat 500 lounge. Error coming on and off in the last few months, but still driving normally, nothing odd coming from brakes so i started investigating.
First i made sure that vacuum hose is clear. Pulled out from brake servo drum, started engine and found that i have plenty of vacuum. Ok, next, i checked the sensor with a multimeter. Found that sensor doesnt work in any circumstance, with or without vacuum. Best bit here is that you can take the actual sensor off, so i removed it carefully from the top of the vacuum hose and took it to bits. The sensor is nothing more than an on/off spring loaded switch soldered on a small electrical board. Rechecked it again with the multimeter, nothing whatsoever. Eventually foound out that the switch itself was working perfectly fine but it wasn't sending the singal to the two prongs going to the harness plug. So, somewhere in line was a bad connection in the soldering. Fixing it was very simple, reheat connections and add more soldering wire where necessary. After resoldering, i tested it again with the multimeter. NOW i was getting a closed circuit between the two prongs, which was turned off when pushing the spring loaded buton. JOB DONE. Having CAREFULLY put everything back together, pushed hoseend back into brake servo drum, connected plug and deleted last ECU errors - VOILA, no p0555 anymore. Whole job didn't take more than 30 mins to complete. Good luck.