These instructions apply to the BMW 1 Series Mk3 (F40) 2019-Present. For other models, please choose your vehicle here.
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Your BMW 1 Series Mk3 (F40, 2019–present) has Auto Start-Stop, which switches the engine off at a standstill to save fuel. If you’d rather keep it running, it’s a quick button press to turn off. Here’s how, and why it sometimes won’t cut the engine.
How It Works on the F40
Brake to a stop (automatic) or stop, select neutral and release the clutch (manual), and the engine shuts off; lift the brake or dip the clutch and it restarts. It only operates once the engine is warm and the battery is healthy.
How to Switch It Off
- With the engine running, press the Auto Start-Stop button — the “A” inside a circular arrow, near the start/stop button or on the centre console.
- A dash light confirms it’s disabled, and the engine idles normally at a stop.
How to Switch It Back On
Press the button again, or simply restart the car — Auto Start-Stop defaults back on every time you switch the ignition off and on.
Why It Sometimes Won’t Activate
- The engine isn’t warm yet, or the climate system is demanding heating/cooling/demist.
- The battery charge is low — common after short trips or a battery change before the new battery was registered; auto-stop is blocked to protect it.
- You’re on a slope, the steering is turned, or you haven’t fully stopped.
If it stopped working after a battery change, the new battery may need registering — see our 1 Series F40 battery guide.
Frequently Asked Questions
Does the F40 remember my Auto Start-Stop setting?
The button resets to on at every start; some cars hold a preference set through iDrive, but the button is per-drive.
Is it bad to keep using it?
No — the F40’s reinforced starter and AGM battery are built for it, and it skips stops when the battery is low.
Why won’t the engine auto-stop?
Usually a cold engine, a low battery, or the climate system demanding the engine.
The light says it’s unavailable — is that a fault?
Often the battery is low or the engine isn’t warm; if it persists after a charge (and battery registration), have it checked.
If a warning light appeared alongside the fault, look up the code on autodtcs.com. To clear a service reminder, see our 1 Series F40 service reset guide.
Disclaimer: The information on this page is provided for general guidance only. Always follow your official service manual and safety precautions when working on your vehicle. We are not responsible for errors, omissions, or any damage resulting from the use of this information.
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