These instructions apply to the Porsche 911 Mk8 (992) 2019-Present.
For other models, please choose your vehicle here.
The automatic stop/start on your Porsche 911 (2019–present) — the 992 — shuts the engine off at a standstill to save fuel. If you’d rather keep it running, switch it off with the dedicated button. The engine cutting out when you stop is normal, designed behaviour rather than a fault, and it’s fitted as standard. On a car like the 992, many drivers simply prefer the engine to idle at a stop — for a more consistent feel in traffic, before working near the engine, or just personal preference.
How Stop/Start Works on the 992
The system only cuts the engine when the car is at a standstill with the brake held, the engine is warmed up, and the 12 V battery has enough charge for a confident restart. A battery sensor and the car’s energy manager watch that charge continuously, so battery condition has a direct bearing on how readily stop/start engages. The chosen driving mode also matters: in the sportier settings the system steps back so the engine stays alert and responsive. When any condition isn’t met, the engine simply idles — that’s the system working correctly, not a fault.
Getting Ready
- No tools needed — this is a console button you press from the driver’s seat.
- Do it with the ignition on, ideally at the start of the drive.
- Locate the Auto Start/Stop button — the ‘A’ with a circular arrow — on the centre console before setting off.
- Note that selecting a Sport driving mode also keeps the engine running, which can be quicker than the button.
Turning Stop/Start Off
- Find the Auto Start/Stop button — the ‘A’ with a circular arrow, on the centre console.
- Press the button once.
- The indicator / dash message confirms the system is off — the engine now idles at a stop.
Turning It Back On
Press the button again, or restart the car — stop/start defaults to ON each time you start the engine. Selecting Sport or Sport Plus also holds the engine running.
Why It Sometimes Keeps the Engine Running
- The battery charge is low or the battery sensor isn’t satisfied.
- The cabin is still heating or cooling.
- The engine is still cold, or a Sport mode is selected.
If Stop/Start Has Stopped Working
- A weak or ageing battery is the most common cause — the system disables itself to protect it.
- After a battery change, fit the correct type; registering it to the energy manager needs Porsche equipment.
- A stored fault can disable it — look up the code on autodtcs.com.
Beyond those, a few everyday factors keep it from engaging: very short trips that leave the battery under-charged, a firm-brake condition that isn’t met if you’re creeping rather than fully stopped, or extreme outside temperatures that keep the climate system demanding engine power. Each of these is normal and clears on its own once conditions return to their usual range.
What Happens Next
Once you press the button, the indicator or dash message confirms stop/start is off and the engine idles at every stop for the rest of that drive. Switch the ignition off and on and it returns to its default on state — the engine will begin cutting out at standstills again. Nothing is stored between journeys, so press the button (or drop into Sport) whenever you next want the engine to stay running.
Frequently Asked Questions
How do I turn off stop/start on a Porsche 911?
Press the Auto Start/Stop ‘A’ button on the centre console; the indicator or a dash message confirms it’s off and the engine will idle at a stop. Selecting a Sport driving mode achieves the same thing, keeping the engine running without a separate button press. Both take effect immediately for the current drive.
Can I disable it permanently?
Not from the button — it resets to ON at each engine start, and there’s no owner setting to make the off state stick. Sport and Sport Plus modes also keep the engine running, so if you routinely drive in a sportier mode you may rarely notice stop/start at all. Otherwise, press the button each time you set off.
Why does the engine keep running with it on?
The system holds the engine on if the battery is low, the cabin is still heating or cooling, or the engine is cold. It only shuts down when a smooth restart is assured and comfort won’t suffer. A selected Sport mode has the same effect. All of this is intended behaviour rather than a malfunction.
Why won’t stop/start work at all?
Usually a weak battery; the 911 disables stop/start to protect it and to guarantee a clean restart. A recently fitted battery that hasn’t been registered to the energy manager can behave the same way, as can a stored fault. If it never engages even with a healthy, warm car, it’s worth scanning for a code.
Does stop/start put extra strain on a performance engine?
No — cars fitted with the feature use a heavier-duty starter and a battery designed for frequent cycling, so normal use doesn’t cause undue wear. The 12 V battery is the main consumable, working harder than in a car without the system. Keeping it healthy and fitting the correct type at replacement keeps everything operating as intended.
Is it fine to leave stop/start switched off?
Yes — with it off the engine simply idles at stops, exactly as cars without the feature always have, with no mechanical downside. You’ll use marginally more fuel in slow traffic, but nothing is harmed. Many owners switch it off in queues or for engine-bay work and leave the default on for open-road driving where it barely activates.
If a warning light came on with the fault, decode it on autodtcs.com.
Independent guide — not affiliated with Porsche. Always follow your official service manual and safety precautions. Read our full disclaimer.