Technical HELP!

[MyFriendlyFiat]

Hi everyone! Please could you try to help me diagnose a fault I have? Any advice will be massively appreciated!

Fiat 500 (2014) 0.9 TwinAir Sport

1) Around September 2025, I noticed the BlueTooth wasn’t working and the mileage was flashing. I called a local Auto-Electrician & he said the car was fine to use, just annoying. He said he’d fix it when he was back from holiday in November 2025.

2) Last week (the Auto-Electrician is still away on holiday so he hasn’t looked at it!), my car failed to start. The dash lit up momentarily but the car didn’t even try to start; I assumed it was a dead battery. I was confident I left nothing on, I checked the boot was closed properly, the radio was off, the lights were off etc, so I had no idea what the fault was.

3) The next day I jump-started it; it started first time. I took it for a ~20 minute drive in 20-60mph areas to give it a decent run, it was fine.

4) The day after this, I drove it around 1-2 miles, and randomly on a 60mph road, the car just died. I didn’t see any warning lights, the only thing I noticed was the dash went black, and the car lost all power. Luckily, I just managed to get it off of the main road mostly, but it really shook me up as I’ve owned the car 5 years now, with absolutely no issues! I turned the ignition, it started up, and I raced back home!

5) I then had an Auto-Electrician look at it; he did the below:
- the oil was around 25% so we topped that to the max line
- the battery initially gave a low ish reading, but after spending 60+ minutes on my car, he’s convinced it’s not the battery and the battery is charging fine he says
- he checked the alternator; this was giving a reading of 14.7, and said that’s very healthy.
- he checked the wires connected to the boot - he said these were fine and in very good condition. I also rarely use the boot and he said try not to, as these wires are prone to breakage!
- he ran a diagnostic check; this showed 1 x PowerSteering fault, 1 x HVAC fault, and 1 x BCU fault (which then spiralled into 12 faults with the BCU). He cleared all faults, and said it was then fine…
- he confirmed the Blue&Me module does need removing and fixing, but he said this wouldn’t cause the car to cut out when driving at 50-60mph randomly.

The only other thing I can possibly pick fault with is my car now appears to have a damaged/broken seal, as over the last week or two, with the cooler, damp weather, it’s been getting condensated. He said there was moisture in the car, which can obviously play havoc with electrics.

Could this have really caused the car to just shut down? I drove it for 1-2 miles on a 40mph road, and then straight onto a 60mph, and the car just cut out, when I was driving on a straight road, in 5th gear and doing around 50-60mph.

The Auto-Electrician is lost, and I am too! Does anyone know what this may be, please? Sorry for the detail but I gathered more was better than less in cases such as this! I’ve never had any warning lights, never had any issues & until last week, I had so much confidence in my car and loved it for just A-B and occasional use, but now I’m really too terrified to use it, in case it does this again!

Thankyou!

 

[JD2023]

I think these fiat's are prone to issues with the earth strap
Under the battery tray there is a strap that goes from the chassis leg to a point on the gearbox under the clutch actuator
I posted a picture of this point last week

Planning earth cable/strap replacement to solve intermittent oil pressure warning alarm on dashboard LCD | FIAT 500 (2007+)

A friend of mine owns a 2017 Fiat 500 with a 1.2l engine, it's a left hand drive (LHD), now 101000 km / 63000 miles . Almost since he's got it a little more than a year ago, he had fugitive warning written on the dashboard's LCD about low oil pressure accompanied with a chime, from what he told...

www.fiatforum.com

Worth a look

Also worth noting that the Blue and me unit needs to be disconnected from the wiring plug if it has failed as this can drain the battery in a couple of days

 

[Mike1alike]

he checked the alternator; this was giving a reading of 14.7, and said that’s very healthy

That is not very healthy! Not healthy at all. It's quite unhealthy. 14.7 V is too much. There's something wrong there!

 

[MyFriendlyFiat]

I think these fiat's are prone to issues with the earth strap
Under the battery tray there is a strap that goes from the chassis leg to a point on the gearbox under the clutch actuator
I posted a picture of this point last week

Planning earth cable/strap replacement to solve intermittent oil pressure warning alarm on dashboard LCD | FIAT 500 (2007+)

A friend of mine owns a 2017 Fiat 500 with a 1.2l engine, it's a left hand drive (LHD), now 101000 km / 63000 miles . Almost since he's got it a little more than a year ago, he had fugitive warning written on the dashboard's LCD about low oil pressure accompanied with a chime, from what he told...

www.fiatforum.com

Worth a look

Also worth noting that the Blue and me unit needs to be disconnected from the wiring plug if it has failed as this can drain the battery in a couple of days

Thank you! That’s really useful. I’ll be honest, I don’t feel confident messing about with it myself, but I’m happy to get someone to have another look it and will run any suggestions by them.

I’m so confused because one auto-electrician said it was fine to keep driving with the Blue&Me unit in the car. The second guy I spoke with said it needed removing, fixing and re-installing, and did also mention they can lead to parasitic drains on the battery if not fixed, and then the third guy (who actually came out to my car last week) didn’t seem to think the unit was related to the car just cutting out; he left the unit in it, but my plan was to call the 2nd guy back as he’s said he can just come and quickly remove it, send it off for repair and then refit it.

 

[MyFriendlyFiat]

That is not very healthy! Not healthy at all. It's quite unhealthy. 14.7 V is too much. There's something wrong there!

What should it be please? I may have misheard him but I’m sure he said it was measuring 14.7 when he tested it. I’ll be honest, he was checking so many things and I was trying to make a mental note of everything, but I may have got the number confused/misheard. I’m by no means technically-minded when it comes to cars.. I know how to drive one, wash one, change a tyre and little else!

 

[Mike1alike]

If it's a fixed alternator (old type, not smart) normal range is 13.8 V - 14.5 V. Anything above that is abnormal.
If it's a smart alternator that's a different game completely, but those are rubbish. They never put out high voltage just after you start the car. They usually put out very low voltage and then high voltage only when you run the car downhill and you don't accelerate. Rubbish!

 

[jrkitching]

Hi everyone! Please could you try to help me diagnose a fault I have? Any advice will be massively appreciated!

When the Blue&Me module fails, it usually fails in such a way as to cause a permanent drain on the battery. This will flatten even a fully charged battery in good condition in a day or two.

Almost certainly this is what has happened here.

The fix is to physically disconnect the Blue&Me module by unplugging it. Note that you have to physically remove the wiring plug.

Once you have done this, and if necessary recharged the battery, the car should work normally again, apart from the flashing mileage. To fix that, you just need to connect the car to diagnostics to remove the Blue&Me module from the configuration.

If you want to continue to use bluetooth, there's a chap on here, @typecastboy, who can fix your old unit for about £60. IIRC if you use his service, the flashing mileage should resolve by itself once the repaired unit is reinstalled - perhaps @typecastboy can confirm this?

The only thing to be careful of is removing the rear panel trim to access the module, as the seatbelt mounting bolt is known to shear off on older cars.

 

[Ralf S.]

What should it be please? I may have misheard him but I’m sure he said it was measuring 14.7 when he tested it. I’ll be honest, he was checking so many things and I was trying to make a mental note of everything, but I may have got the number confused/misheard. I’m by no means technically-minded when it comes to cars.. I know how to drive one, wash one, change a tyre and little else!

No.. 14.7v is perfect if the engine is running at a fast idle. You can test the alternator output "analogue"... by putting on every electrical load you can (lights, rear window demister, heater fan etc.) and look at the lights when the engine is idling. If you increase the revs slowly to 2000rpm, the lights should not get brighter. If they do, the alternator (regulator) is moody and your alternator may not charge the battery... but 14.7v sounds optimal.

Your problem is likely a knacked Blue&Me module. It's not easy to access but you can disconnect it from the power lead to solve your drain problems.. although the flashing mileage would need a proxy alignment to resolve.


Ralf S.