These instructions apply to the DS 9 Mk1 (X) 2021-Present. For other models, please choose your vehicle here.
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The automatic stop/start on your DS 9 (2021–present) cuts the engine at junctions to save fuel. On the E-Tense hybrid the changeover is smooth, but you can still switch the system off when you’d rather keep the engine running — with a single button.
Turning Stop/Start Off
- Find the stop/start button — the ‘A’ / ECO OFF button, usually on the centre console or dash.
- Press the button once.
- The warning light illuminates to confirm the system is off — the engine now idles normally at a stop.
Turning It Back On
Press the button again, or restart the car — stop/start defaults to ON every time you start, so press the button each drive if you want it off.
Why It Sometimes Keeps the Engine Running
Even with stop/start active, the DS 9 holds the engine on when conditions aren’t met, for example:
- The 12 V battery charge is low, or the battery sensor isn’t satisfied.
- The cabin is still heating or cooling to the set temperature.
- The engine is still cold, or the hybrid system needs to run the engine.
If Stop/Start Has Stopped Working
- A weak or ageing 12 V battery is the most common cause — the system disables itself to protect it.
- After a battery change, fit the correct type and let it learn over a few drives.
- A stored fault can disable it — look up the code on autodtcs.com.
Frequently Asked Questions
How do I turn off stop/start on a DS 9?
Press the ‘A’ / ECO OFF button; the warning light confirms it’s off.
Can I disable it permanently?
Not from the button — it resets to ON at each start.
Why does the engine keep running with stop/start on?
The system holds the engine on if the battery is low, the cabin is still heating/cooling, or the engine is cold.
Why won’t stop/start work at all?
Usually a weak 12 V battery; the DS 9 disables stop/start to protect it.
If a warning light came on with the fault, decode it on autodtcs.com.
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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