These instructions apply to the Fiat 500 (312) 2007-present.
For other models, please choose your vehicle here.
Your Fiat 500 (312, 2007–present) with Start&Stop shuts the engine off at a standstill to save fuel and lower emissions in town driving. When you’d rather keep it running — crawling traffic, a hot day, or before any under-bonnet work — one button switches it off. It’s a comfort preference rather than a fault: the engine cutting out at a red light means the system is working, and turning it off does the car no harm.
How Start&Stop Works on This Model
On the 500 the system checks a handful of conditions before it will cut the engine. It looks at the 12 V battery’s state of charge, the engine coolant temperature, cabin heating or cooling demand, whether you’re on a slope, and whether the brake is held with the car fully stopped. Only when all of those are comfortable does it shut the engine off, restarting the moment you lift off the brake. Each restart draws on the battery, so a healthy 12 V unit is the key to smooth Start&Stop behaviour on this small car.
Before You Start
- Have the engine running and the car at a standstill — you set this during a normal drive, not with the ignition off.
- Find the A-in-arrow button before setting off so you’re not searching for it in traffic.
- If you’re disabling it for engine-bay work, switch the ignition fully off so the engine can’t auto-restart.
- Expect to press it again each drive — the setting doesn’t carry over between trips.
Turning Start&Stop Off
- Find the Start&Stop button — marked with an A inside a circular arrow — on the dash or centre console.
- Press it once; the indicator confirms it’s off and the engine stays running at stops.
Why It’s On Again Next Time
The 500 switches Start&Stop back on at every ignition cycle — there’s no permanent off. Press the button at the start of each drive if you don’t want it.
If the Engine Won’t Stop at Idle
If Start&Stop is on but the engine keeps running, it’s almost always an inhibit condition, not a fault. Common reasons on the 500:
- The 12 V battery charge is low — an ageing or under-charged battery is the usual cause.
- The cabin still needs heating or cooling, so the engine keeps the climate system fed.
- The engine hasn’t reached normal temperature yet on a cold morning or short trip.
- You’re stopped on a gradient, or the brake isn’t held firmly enough.
- The bonnet is open, or outside temperatures are very high or very low.
- On mild-hybrid 500s the engine behaviour is managed automatically and differs from the plain petrol.
What to Expect After
Once you press the button, the indicator confirms Start&Stop is off and the engine keeps running at every stop for the rest of the drive. Fuel use rises a little in heavy traffic, which is the trade-off. Because the setting resets, the 500 arms it again next time you start the car, so press the button once more if you want it off.
Frequently Asked Questions
How do I turn off Start&Stop on a Fiat 500?
Press the ‘A’ circled-arrow button on the dash or console; the indicator shows it’s disabled for this drive. The engine will then keep running at every stop until you switch the car off. No menu setting is needed — a single button press handles it on this model.
Can I disable it permanently?
No — the 500 re-arms Start&Stop at every ignition cycle, so it always defaults to on. You have to press the button per drive. Aftermarket memory modules exist that hold the last setting, but that’s outside standard owner use and can affect warranty cover.
Why didn’t the engine stop today?
Low 12 V battery charge, ongoing climate demand, a cold engine, a slope, or a brake pedal not held firmly will all keep the engine running. This is by design — the system only cuts the engine when conditions are comfortable, so days where it rarely stops are normal rather than a fault.
Is it bad to leave it on?
No — the starter and battery on Start&Stop 500s are specified for the extra cycling, so leaving it enabled is fine. The main thing to watch is the 12 V battery: as it ages the system can turn erratic, stopping less often, which points to the battery needing attention rather than a fault in the feature.
Does the 500 need a special battery?
Start&Stop cars use a battery built for repeated shallow discharge and recharge, so a like-for-like replacement matters. Fitting a plain battery not rated for stop-start duty can make the system behave poorly or stop working, so match the correct type if you renew it.
Should I turn it off before working under the bonnet?
Yes — if you’ll be near belts or moving parts, switch the ignition fully off rather than just pressing the A button. Disabling Start&Stop still leaves the engine live and able to run, so shutting the car down completely is the safe way to work in the engine bay.
If a Start&Stop fault shows, it usually points to the 12 V battery — see our 500 battery guide, or look the code up on autodtcs.com.
Independent guide — not affiliated with Fiat. Always follow your official service manual and safety precautions. Read our full disclaimer.