These instructions apply to the Mercedes C-Class Mk5 (W206) 2021-Present. For other models, please choose your vehicle here.
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The Mercedes-Benz C-Class W206 (2021–present) has ECO start/stop that switches the engine off at a standstill to save fuel. On the W206 the 48 V mild-hybrid system makes the restarts especially smooth, but if you’d still rather keep the engine running you can switch the function off.
How to Turn Off ECO Start/Stop
There are two ways, depending on your car:
- ECO button: if fitted, press the ‘ECO’ button on the dashboard or centre console — the display confirms start/stop is off.
- MBUX menu: on cars without a physical button, open the touchscreen menu and go to Vehicle → ECO start/stop (or the relevant assistance/efficiency menu) and switch it off.
It Resets Every Drive
Like nearly every car with this feature, the C-Class re-enables ECO start/stop each time you restart. There’s no permanent factory ‘off’ — switch it off again at the start of each journey if you prefer.
Why Switch It Off?
- Before engine-bay work — avoids an unexpected restart.
- Stop-go traffic — stops constant cycling.
- Maximum cabin cooling/heating on extreme days.
The system also holds the engine running on its own when the battery is low, the cabin needs heating/cooling, or you’re on a hill — that’s normal.
Frequently Asked Questions
How do I turn off auto stop/start on a Mercedes C-Class?
Press the ECO button, or on MBUX go to Vehicle → ECO start/stop and switch it off.
Can I disable it permanently?
No — it resets to on at every restart. Switch it off each drive.
Why did stop/start come back on?
Restarting the car re-enables it automatically.
Why won’t the engine stop sometimes?
A low battery, climate demand or a gradient holds the engine running — that’s by design.
If a start/stop or battery fault light shows, look it up on autodtcs.com. See our W206 battery 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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