Technical Help Please

[Brassnadz]

Hi everyone,

Been a very long time on this group. Some may remember my late mum had a bright orange Fiat punto and you lovely lot helped me and my late mum. Then sadly she passed away in 2017 and I had to part with mum's punto but I got a Fiat 500 in baby blue and done some decals in memory of her. Never missed a beat that car. Now in 2023 I changed to a Fiat 500x due to circumstances. Oh boy and please see below. I'm losing the will with this car. I don't want to because I know my late mum would've chose this car.

I'm hoping someone may have come across this before on a Fiat 500X 1.0 FireFly.

My car is a 2020 Fiat 500X Sport with around 36,000 miles.

For some time I have been experiencing an intermittent issue which usually occurs during cold start or during the transition from fast idle down to normal idle. On a few occasions the engine has chugged, run roughly or appeared to misfire briefly, before then clearing and driving normally.

The fault is very intermittent and the car can then complete long motorway journeys without any issues at all.

The main fault code recorded is P1471. I have also had moving misfire faults recorded on different cylinders at different times rather than one specific cylinder repeatedly failing.

The vehicle has been inspected by a Fiat dealer (Stoneacre) and I have raised the possibility of software updates and Stellantis technical bulletins relating to P1471. I have been told the vehicle was checked, however the fault remains unresolved.

More recently I discovered evidence that the same P1471 code appears to have been recorded during a warranty visit in February 2024, meaning the same code has now reappeared over a year later. I booked it in with stoneacre as closest to me very begrudgingly and 2 days after booking the eml light disappeared on its own.

Things I am wondering about include:

- FireFly software/calibration issues
- Upstream lambda sensor
- EVAP purge system
- Wiring or sensor faults
- Battery/voltage related issues
- Anything else common on the 1.0 FireFly engine

Has anyone experienced recurring P1471 faults, rough idle during idle transition, or intermittent misfires on a 1.0 FireFly and eventually found the cause? Oh my reversing camera won't work. It had brief flick of life the other day and then not working. Apply the code u145 I think but no communication. I've also got a wobbly drivers seat which is something to do with bloster/seat sprocket I think. I mean this car may have been a Friday night job. I've not owned the car 3 years yet. Stoneacre nor Fiat will help me. It was £15,000 car sorry for long post. I'm also in Wrexham but willing to travel.

Any advice or experiences would be greatly appreciated.

Thank you.

Sounds like plug wires . Check ohms resistance of each wire. 1 at a time so as to not mix up firing order. Take pictures first for double check purposes.

 

[Smudge 123]

I certainly wouldn't know where to start with wires and it's completely gone over my head. Plug wires?

 

[Brassnadz]

I certainly wouldn't know where to start with wires and it's completely gone over my head. Plug wires?

Spark plug wires u test th resistance using a multimeter. Get multimeter at harbor freight for less than $5. Google search "Spark plug wires test ohms resistance " .ur asking for help, so u gotta hav some idea how to fix things rite?

 

[Ralf S.]

I certainly wouldn't know where to start with wires and it's completely gone over my head. Plug wires?

I'm not convinced.. the Firefly uses coils over the spark plugs so there is no conventional HT leads to fail.. and in any case they're brand new (36k). They just don't fail, except when they do.

If the fuel economy has degraded, try testing the lambda sensor. It will at least eliminate that and this test is free and easy, even if not definitive;

Find an empty stretch of road... just drive off from rest as normal.. but without too much gas, so the car accelerates slowly. Second or third gear is best for the test since you don't want to pick up engine speed too quickly.

Slow down and let the revs drop o 1200rpm, then accelerate as slowly as possible/least amount of throttle as you can until you get to 2000rpm.
As the engine passes through 1500-1600 rpm listen out for any hesitation, glitches or surging that clears up by 1800rpm. Try it a few times to be sure.

If there's a hesitation at ~1600rpm then the lambada could be on the way out. This is where its heater switches off, and engine gas alone has to keep it hot. If it hesitates, it could be that the lambda can't work properly without the support of its heater, so it could be a candidate for further testing (or just replace it might be cheaper).

Otherwise.. I still suspect something related to that no.2 cylinder MA solenoid. There must be a way the workshop can test it "in place" using diagnostics.. but it needs the correct factory software, so I've never done it.


Ralf S.

 

[Smudge 123]

Stoneacre told me it wasn't the lamda sensor at all but there was "open loop“ detected the last time the car did this on the obd2 scanner. The car keeps saying air flow something on the ob2 scanner 2hixh stoneacre ignored, then 2 people have said the car is too sensitive when fast idle comes off and the bulletin put out by steliantis so I'm confused. It's been running fine apart from the fuel and now suddenly the camera works. The sparks were changed in November last year. I wonder if the garage you mentioned S103 would take a look? Or would it be too complex. The car has mot in July and god knows where I'll take it.

 

[Smudge 123]

Spark plug wires u test th resistance using a multimeter. Get multimeter at harbor freight for less than $5. Google search "Spark plug wires test ohms resistance " .ur asking for help, so u gotta hav some idea how to fix things rite?

Yes I'm asking for help but I'm also not mechanically minded. My health conditions stop me from doing a lot things and in all honesty I don't want to go poking around something I'm not comfortable with. It could be the battery but as far I know no one has test loaded the battery. The car was taken to Halfords who said the battery was 80% and would not load test. Stoneacre said the battery was fine too.