Dear coclubbers!
I have a disappearing bug in my 2009, Fiat 500, AT, 1,4.
Spontaneously a "Check Engine" sign appears and transmission stops to switch shift to Neutral mode. When i position Robot joystick to Neutral mode a sign on the dashboard appears - "Operation not admissable". Several times that damn error apperared and disappeared.
One day right in the middle of the ride the car refused to switch to the first shift and we had to call evacuator to reach the car-service. When i got of the evacuator all the errors have diappeared again and the car was able to move without help. In the service they said it was because of the old clutch (I hope that is the right word in English, i hope you understood), so we changed it. Several weeks everything was OK and yesterday that f...ng problem appeared again with the same error.

Any advices on how to fix it? My pregnant wife is begining to tire of that constantly-need-to-repair-something-car


When i scan for errors there is only one error in history - P0120 error (Throttle/Pedal position sensor/Switch A Circuit)


P.S. Do you now how here in Russia some guys call Check Engine sign? - Jackie Chan

I believe this is the problem that typecastboy has had recently?

Yes. I changed the throttle pedal, then the throttle body but still the fault kept coming back. It ended up being the ECU. There was a voltage too high in one of the cables from the pedal to the ECU which gave a TPS sensor fault.

So how did you fix the problem? Have you changed ECU or a cables? What did you do? Because in the car service they still can`t explain that glitch.

I bought a new ordeal in eBay first. Changed that, reset the code, still the same. Then bought a throttle body on eBay and tried that too, just the same. I gave up and took it to a garage. He had the car 4 weeks and found out that the ECU had a fault in one of the live feeds. I bought a second hand ECU on eBay and the garage had to send it away to be virginised. It was then fixed.

Thank you for the explanation. May I ask you more questions then?
Have you experienced this pedal error constantly or it was a spontaneous mystic bug out of nowhere every time? Because it disappeared as I touched the wires beneath the driving wheel -May be it is just the bad wires over there? I scheduled a visit to the official dealer tomorrow but I seriously doubt they will be able to give the right diagnosis...

I had bought the car damaged, repaired it. Driven it about 3 miles for its MoT and it was fine. Drove it home from the MoT it was fine. Then I took it to bodyshop for some work and on the way home from the bodyshop, dong!

Reset it and as soon as I got into second gear it went dong!

After that, it just constantly did it. I have heard that it can be intermittent sometimes. Yours may well be the pedal. It's trial and error to find it unfortunately.

Well for now after the visit to the official dealer they said it is either electric cables or a pedal. Theu just reconnected the cables. For now the problem is gone, but if it appears again, they said i`ll have to change the pedal.

I`ll keep in touch )

I bought a new pedal on eBay for £24 Gbp. I dread to think how much a new one is. It's fiddly but only held on by two bolts. You need long reach socket to get to it though as the bolts are really long.