500 2019 500 accelerating by itself

[chimp450]

Hi, I joined a while ago but this is my first post. We have a 2018 500 Lounge which we've had from new and has been totally trouble free, so we have just bought it at the end of the PCP. My son's wife has the same, a 2019 which is just 3 years old and has developed a fault where it accelerates of its own accord, with no pedal input. it has been back to the dealer on several occasions but they can't replicate the problem and are basically telling her there is nothing wrong with it. It will actually pull up a car park ramp without touching the accelerator, and the cures itself after a few minutes, driving normally from then on.
Has anyone experienced this, or got any ideas?
Thanks in advance
John

 

[John202020]

If you dip the clutch when its doing its thing what does the engine do rev or return to idle with your foot off?
If you allow it to accelerate how fast will it get to?

 

[RalphM]

If it's a Diesel she is letting the revs drop to low, needs the next lower gear.

 

[mj2k]

Could be something to do with the electronic throttle pedal, throttle position sensor or suchlike. Worth hooking it up to a diagnostic code reader to see if there are any fault codes logged as a first step before grubbing around under the bonnet looking for issues

 

[chimp450]

Could be something to do with the electronic throttle pedal, throttle position sensor or suchlike. Worth hooking it up to a diagnostic code reader to see if there are any fault codes logged as a first step before grubbing around under the bonnet looking for issues

Thanks for the replies.
Firstly it's a 1200 petrol, as is ours. I don't know if the revs rise or fall with the clutch disengaged on her car. The dealer has put it on the diagnostics and found no faults.
I've managed to replicate it in our car today, from a standing start in 1st gear let the clutch in with no accelerator pedal input and it pulls away and up a slope, which is exactly what she gets. The rev counter stays around 1000. That's not the way we usually drive, prefer to rev it a bit, and have never noticed this in 4 years.
I now think it may be an anti-stall setting, I've done some more research and found comments about it on the Fiat 500 Owners.com forum, USA I think. Also allows you to idle along in slow moving traffic without having to keep declutching etc. Might be a good thing? Apparently also available on many other makes and models, including Vauxhall, VW/Audi, Mini, Honda, SAAB etc.
Live and learn!
Thanks again, John

 

[varesecrazy]

Yes ...its a standard feature ,

Not as pronounced in my 2018 1242cc 500 as in my 875"cc punto

 

[chimp450]

Yes ...its a standard feature ,

Not as pronounced in my 2018 1242cc 500 as in my 875"cc punto

Thanks for confirming it

 

[RalphM]

The tick over speed is set by the ecu and it will try to maintain what ever its set to
so when you let the clutch up or hit a hill it will try to hold those revs and so the
feeling of accelerating, it sounds normal to me most fly be wire systems do the same
to some degree.

 

[chimp450]

Thank you, I'd never noticed it before on any of the cars we've had. Maybe it's the way we drive.
My d-i-l is now reassured that there is nothing wrong with her car, she was worrying because it's just out of warranty.

 

[TrevC]

Yes, the revs rise when you raise the clutch pedal so it will pull away slowly without using the accelerator. The 2011 twinair I had didn't do it but the 2015 1.2 that my wife had did. Useful for creeping in traffic. Interestingly this feature was much more aggressive in the 1.4 Multiair 500X I had, that sometimes felt it was getting away from you in, say, 3rd gear around town - it would stay at 15-20mph with your foot off the accelerator until you dipped the clutch.

 

[vexorg]

So it's the small rise in rpm, not the car rapidly pulling away without touching the pedal.

 

[Ralf S.]

A lot of cars have this "anti-stall" feature now. I think they can do it when the car is drive by wire, since the brains control the throttle position, rather than the old school/analogue "cable". It's handy when you're in traffic, since the car can "creep" a bit without you needing to slip the clutch/give it throttle inputs.. but it does feel like someone else is driving the car when it does it...


Ralf S.

 

[chimp450]

Thanks TrevC, confirms what I've experienced.
In reply to vexorg, in our car the revs rise slightly to 1000, without using the acc pedal, as you let the clutch in and then stay at 1000 with no acc pedal use. I kind of like it as a feature now I've found it, but not sure if I would use it in traffic.

 

[vexorg]

but it does feel like someone else is driving the car when it does it...

Sounds as bad as the modern cruise control that let you change gear. Change down for a slip road and the car / van takes off on it's own, not a subtle increase in revs.

 

[TrevC]

The other thing the 500X did, but the little 500 didn't, was restart the engine with the starter motor if you stalled it and quickly dipped the clutch. Only happened a couple of times, but saved some embarrassment.

 

[varesecrazy]

From what you said earlier.. maybe the old 500 had no clutch switch?

My 2013 punto ta rises revs to @1250
Noticably higher than the 2018 500 does

The 2013 panda ta doesnt seem to do it at all.. again probably no clutch switch.

 

[TrevC]

I'm sure that my 2011 500 didn't have the clutch related rev increase. Possibly something done to help comply with Euro 6 requirements?