These instructions apply to the Fiat 500X Mk1 (334) 2015-present.
For other models, please choose your vehicle here.
Your Fiat 500X (334, 2015–present) with Start&Stop shuts the engine off at a standstill to save fuel and cut emissions. When you’d rather keep it running — crawling traffic, a hot day when you want the air-con at full tilt, or before any under-bonnet work — one button switches it off. The system is a normal economy feature, not a fault, and the ‘A’ symbol simply reports whether it’s active.
How Start&Stop Works on the 500X
When you stop and hold the brake with the gearbox in neutral, the engine shuts down; releasing the brake (or dipping the clutch on a manual) restarts it instantly. It only cuts out once a set of conditions is satisfied — chiefly a well-charged 12 V battery, an engine at temperature and a cabin that’s already comfortable. The 500X keeps an eye on battery state of charge, so a car used mainly for short journeys will often keep the engine running because the battery hasn’t recovered enough to allow a stop.
Before You Start
- Do this with the engine running, or the ignition fully on, so the button and indicator respond.
- Find the A-in-a-circular-arrow button before you set off rather than in the middle of a junction.
- If you’re about to open the bonnet, switch the system off first so the engine can’t auto-restart.
- Bear in mind the setting only holds for the current drive — there’s no permanent-off menu.
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 500X 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.
When the Engine Won’t Stop Anyway
If Start&Stop is on but the engine won’t cut at a standstill, it’s normally one of these — nearly all of it normal, protective behaviour:
- The 12 V battery charge is low — the most common cause, and typical after several short trips.
- The engine hasn’t warmed up yet, so it keeps running to reach temperature.
- The cabin still needs heating or cooling and the climate system is drawing on the engine.
- You’re on a gradient, or the car hasn’t fully stopped with firm brake pressure.
- The battery is worn out — if the engine almost never stops, an ageing 12 V battery is the usual reason and worth testing.
What to Expect After
Once you press the button, the ‘A’ indicator shows the system is off and the engine idles normally at every stop for the rest of that drive. At the next start it re-arms on its own, so press the button again if you want it off. Nothing is stored or wiped — it’s simply a per-trip toggle.
Frequently Asked Questions
How do I turn off Start&Stop on a Fiat 500X?
Press the ‘A’ circled-arrow button on the dash or console once. The indicator confirms Start&Stop is disabled and the engine will stay running at stops for the rest of that drive. It re-arms at the next ignition cycle.
Can I disable it permanently?
No — the 500X has no permanent-off setting for Start&Stop. It re-enables itself every time you start the car, so the only way to keep it off is to press the button once at the start of each drive.
Why didn’t the engine stop today?
Usually the 12 V battery charge was too low, the engine hadn’t reached operating temperature, or the cabin still needed heating or cooling. A slope, or the brake not held firmly enough, will also keep the engine running. All of this is by design.
Is it bad to leave it on?
No — Start&Stop is built for constant everyday use and the 500X’s starter and battery are specified for it. A tired 12 V battery can make the cut-and-restart cycle feel erratic, so if it seems rough it’s worth having the battery tested.
Does the air conditioning keep working when the engine stops?
The fan keeps blowing but the compressor can’t run with the engine off, so on a very hot day the system may hold the engine running to keep cooling. If you want guaranteed uninterrupted air-con in traffic, switching Start&Stop off is the simplest fix.
Does switching it off harm fuel economy much?
Only marginally. Start&Stop saves a little fuel in stop-go conditions, so leaving it off costs you a small amount there and nothing on the open road. Many owners accept that trade for a smoother idle in slow queues.
If a Start&Stop fault shows, it usually points to the 12 V battery — see our 500X 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.