Fiat 500 - P1220 fault code - any ideas?

boyoutofhell

Good evening,

Don't know much about cars, so I'll explain this the best way I can, sorry in advance.

About a year ago, I bought a used Fiat 500 (30k km mileage, 1.2 l petrol engine) as my first car to learn how to drive a manual. All good until recently, when completely out of the blue the engine light went on and the following messages pop up every time I turn the car on: ESP unavailable, Hill holder unavailable, Start/Stop unavailable please check manual (there's nothing about it in the manual btw).

Before anything else, I bought an OBD2 scanner, plugged it in and it gave me fault code P1220: Throttle valve position track1 and track2. Took it to where I bought it from, they diagnosed it themselves and told me the throttle pedal sensor is at fault and the throttle pedal needs to be replaced. Then I took it to an official Fiat dealership and repair shop, they ran a diagnostic and said the same thing, so I paid for the throttle pedal replacement which was done today. Lo and behold, new throttle pedal but the fault codes and error messages are still there, so I paid 300 euros for nothing. The Fiat dealership are stumped and have no idea what's going on or what's causing the issue.

Has anyone experienced this or heard about similar issues? Had to postpone my driving test two times already and looks like I'll have to do it again, because I doubt they'll let me take it in a car with a check engine light on.

Many thanks in advance!

mk7r

Well that code relates to the throttle body itself not the pedals so I'm not sure where they were going with that. There is a pair of potentiometers on the pedal and a pair on the throttle body, from your code the ECU is not happy with the signal its getting from the throttle body itself

GPoint

When I owned a Fiat few years ago I had same experience with the dealer, payed for work, issue came back, payed again for diagnostics and still not fixed. Ended up researching the problem and bringing them printed instructions so then they fixed my problem.

I would avoid buying a car that is not popular on Irish roads for the fact that you would struggle to find a decent mechanic who understands it and able to fix it.

boyoutofhell

https://www.boards.ie/discussion/comment/121490070#Comment_121490070

Wish I could do what you did, but I've scoured the Internet and no clue what the issue is. What cars are popular on Irish roads and won't give mechanics headaches repairing it? (Please don't say Hyundai or Ford 🤞)

cnoc

https://www.boards.ie/discussion/comment/121491868#Comment_121491868

Toyota Yaris

Fabio

https://www.boards.ie/discussion/comment/121491868#Comment_121491868

Fiat 500s are fairly simple cars to keep on the road (and they're very nice too).

There is really no point in buying a new car just because of a small fault code like this so what I would suggest is, try and find an independent garage that have some experience with any Fiat or Alfa Romeo models. The main Fiat dealers here are few and far between and the one I dealt with wouldn't exactly be considered enthusiasts of the brand!

Some good info here: https://www.fiatforum.com/threads/code-p1220.454499/ and https://www.fiatforum.com/threads/limp-throttle-when-engine-is-warm-p1220.474791/

Also some on an Alfa forum here (I know, different brand, but they share some platforms): https://www.alfaowner.com/threads/intermittent-throttle-issue-p0220-p1220-p1221.95539/

Could be incorrect resistance between two sensors going to from the potentiometers to the ECU or it could be that you need a new ECU (or a used unit that has been wiped and reset). Could be something else two but that's what I got from a cursory glance at those forums. Could be the Throttle Position Sensor needs cleaning out too and check the idle control valve if that's a separate thing.

One more thing - basic code readers don't play well with Fiat or Alfas. You need a thing called MultiECUScan (http://www.multiecuscan.net) which will give proper details on the problem. Fiat dealers should be working with that.

Hellrazer

Worked in Fiat for a long time - check the block connector on the throttle pedal and see if the pins are corroded - check both sides of the block connector but since you have a new pedal installed it will more than likely be the connector that plugs into the pedal.. They used to rust and give the P1220 code.