These instructions apply to the Jaguar XF Mk2 (X260) 2015-Present.
For other models, please choose your vehicle here.
Your Jaguar XF (2015–present) switches the engine off at a standstill to save fuel, then restarts it as you pull away. If you’d rather keep it running — in traffic or by preference — you can switch the system off in one press. This is a normal, designed feature rather than a fault, and the light that appears when you disable it simply confirms your choice for the current drive.
How Stop/Start Works on the XF
The system watches a set of conditions dozens of times a second and only cuts the engine when they all line up: the car is fully stopped, the brake is held, the engine is warm, the cabin is near its set temperature and the 12 V battery has enough charge in reserve. The moment you lift off the brake — or any of those conditions changes — it restarts. Because the XF relies on a healthy battery to power everything during the brief shutdown, battery condition is the single biggest factor in whether stop/start behaves. That is also why it resets to on at every start: it is treated as the default economy mode rather than a setting to be remembered.
First, a Few Checks
- Have the engine running — the button toggles the system, it doesn’t start the car.
- Do it while stationary so you can see the confirmation indicator.
- Know that the setting lasts only for the current drive; the next start returns it to on.
- If you are about to work in the engine bay, switching stop/start off avoids an unexpected restart.
Turning the System Off
- With the engine running, press the stop/start (ECO) button on the centre console (an “A” inside a circular arrow).
- An indicator confirms the system is off; the engine now stays running at a standstill.
The system defaults back to on each time you start the car, so disabling it is a per-drive choice — press the button again to re-enable it.
When the XF Disables Stop/Start Itself
Even with the system on, the XF won’t stop the engine when it isn’t appropriate, so continued idling isn’t necessarily a fault. It keeps the engine running when the cabin is still reaching temperature, the engine is cold, or the 12 V battery charge is low.
If Stop/Start Won’t Cut the Engine
- Check the battery. The system needs a healthy 12 V battery and a settled battery-management system; an ageing battery, or one that has recently been disconnected, is the usual reason it stops cutting out.
- Give it a longer drive. After a short trip the engine and cabin may not be fully up to temperature, so the system holds the engine on.
- Seat belt fastened, doors and bonnet closed — an open one inhibits it.
- Press the brake firmly and come to a complete stop — a gentle or rolling stop may not satisfy the trigger.
- Steep hills and high electrical demand (heated screen, full climate, lights) can legitimately hold the engine on.
- Fault light? A charging or sensor issue stores a code — decode it on autodtcs.com.
Once It’s Done
With the system switched off, the indicator stays lit and the engine idles normally at every stop for the rest of that drive. There is no lasting change and nothing to reset — the next time you start the car, stop/start is active again and the light is off. Toggling it on and off does not harm the engine or the starter, both of which are built for frequent restarts.
Frequently Asked Questions
How do I turn off stop/start on a Jaguar XF?
With the engine running, press the ECO button on the centre console — the one marked with an “A” inside a circular arrow. An indicator lights to confirm the system is off, and the engine will idle normally at every stop until you next restart the car, when it returns to on automatically.
Does the setting stay off?
No. The XF treats stop/start as the default economy mode, so it resets to on every time you start the engine. There is no menu option to make the button’s off state permanent, so if you prefer it off you press the button once at the start of each drive.
Why has my XF stopped switching the engine off?
Most often a low or ageing 12 V battery, or a battery-management system still relearning after a recent disconnection. It can also be perfectly normal: a cold engine, a cabin still reaching temperature, a short trip, a steep hill, or a seat belt or bonnet not fully closed will all hold the engine running.
Is leaving stop/start on harmful to the engine?
No. The engine, the reinforced starter and the battery are all designed for repeated automatic restarts, and the system only cuts the engine when doing so is safe and efficient. Leaving it on is the manufacturer’s intended setting and causes no extra wear beyond what the car was engineered to handle.
Does switching stop/start off use more fuel?
Slightly, in the situations where the engine would otherwise have shut down — typically stop-start traffic and long waits at lights. On a flowing drive the difference is negligible because the system rarely intervenes there anyway. Many owners accept the small penalty in exchange for smoother behaviour in heavy traffic.
Should the battery be a specific type on the XF?
Stop/start cars use a battery built for frequent deep cycling, and fitting the correct specified type matters if you ever replace it. An unsuitable or worn battery is the most common reason the system quietly stops working, so it is worth confirming the right specification with your handbook or a battery supplier before buying.
If a warning light appeared with the change, decode it on autodtcs.com.
Independent guide — not affiliated with Jaguar. Always follow your official service manual and safety precautions. Read our full disclaimer.