What is the A symbol on the dashboard?
On most modern cars, the A icon inside a circular arrow marks the Auto Start-Stop system. It signals that the engine can automatically shut off when the car is idle to save fuel, and restart when you’re ready to move again.
What the A symbol indicates in practice
This indicator is a status light for the Auto Start-Stop feature. Its appearance and color can vary by manufacturer, but the core idea is the same: the engine may shut off during short stops (like at traffic lights) and automatically restart when needed.
Before exploring the details, note that some vehicles show variations of the symbol or use different wording. The general concept remains the same: the car is using, or available to use, automatic engine shut-off to improve efficiency.
- When the system is active, the engine may shut off automatically at complete stops and restart when you press the accelerator or release the brake, depending on the model.
- The indicator may be green or white while the system is operating smoothly. An amber or yellow light often means the system is temporarily unavailable due to conditions like battery state, temperature, or electrical load.
- Some cars show “A OFF” or a similar cue to indicate the feature has been manually disabled by the driver or is currently inactive.
- Auto Start-Stop can be less noticeable in hybrids or plug-in hybrids, where electric motors may handle propulsion at stops, or where the system behaves differently due to battery management.
- Environmental and safety factors (e.g., air conditioning load, battery health, engine temperature) can prevent automatic shut-off even when the symbol is visible.
In addition to the list above, remember that how the A symbol behaves can differ between makes and models. Always consult your owner’s manual for the exact meaning on your vehicle.
When the A system engages or does not engage
The Auto Start-Stop system is designed to balance fuel savings with comfort and safety. It typically engages when the car is stationary, the transmission is in drive, and other conditions are suitable. It may not engage if the battery is low, the climate control requires extra power, or the engine is too cold or too hot.
- Common engagement conditions include idle at a complete stop with safe restarting conditions.
- Common reasons it won’t engage include a low battery, high electrical demand (air conditioning at max heat/defrost), or a request from the driver to keep the engine running (manual override active).
- Some vehicles automatically re-enable the system after a restart, while others retain the last setting until you manually change it.
The exact behavior varies by vehicle, so it’s possible to see the symbol lit and still feel the engine staying on in certain scenarios, or to see the symbol off even when the car is capable of stopping the engine at idle.
How to control the Auto Start-Stop system
Most cars provide a dedicated control for Auto Start-Stop near the gear selector or on the dashboard. Here’s how owners typically manage it:
- Look for a button labeled with an A and a circular arrow or a clearly marked “Auto Start-Stop” control. Press it to toggle the feature on or off.
- Some vehicles allow a temporary override by pressing and holding the brake pedal; the system will remain off until you restart the engine or certain conditions are met.
- If you prefer to keep it off, use the control to disable it; note that in many cars the system may re-enable after the engine is restarted or after a set period, depending on the model and conditions.
- Driving habits or frequent short trips can influence how often the system engages; consult the manual for any model-specific nuances.
When in doubt, check the owner’s manual or contact the dealership for model-specific guidance. Some manufacturers also provide on-screen tutorials or help prompts in the vehicle’s infotainment system.
Brand-specific variations
Common representations across brands
The A symbol can appear in slightly different forms. Some brands show a simple A inside a circular arrow, others display “A OFF” when disabled, and color cues (green, white, amber) help convey status. Climate control settings, battery health, and driving conditions can influence whether the system engages, so appearances can vary even within the same vehicle family.
In practice, the concept remains consistent: Auto Start-Stop is a fuel-saving feature that optimizes engine usage at stops. If you notice unexpected behavior, or the symbol behaves differently than you expect, your dealer or service manual can explain the specifics for your car.
Summary
The A symbol on a dashboard most commonly denotes the Auto Start-Stop system, which can shut off the engine at idle to conserve fuel and automatically restart when needed. Its exact appearance, color, and behavior vary by manufacturer and model. You can typically control it with a dedicated switch, and it may be temporarily overridden by the driver or automatically disabled under certain conditions. For precise guidance, refer to your vehicle’s owner’s manual.
What does the A with a circle mean on a Mercedes?
Frequently Asked Questions. What does the “A” in a circle mean on a Mercedes dashboard? A circle with “ABS” indicates a fault in the ABS. An “A” surrounded by a clockwise arrow refers to the ECO Start/Stop function. Press the button to toggle it.
What does the A off symbol mean in a car?
The "A OFF" symbol in a car's dashboard means you have disabled the automatic engine start/stop system, which is designed to save fuel and reduce emissions by turning the engine off when the car is stationary. When the symbol is illuminated, the engine will not automatically shut off when you stop, and will only turn off again if you press the button to reactivate the system.
What the symbol means
- "A" with a circular arrow: This symbol typically represents the automatic start/stop system.
- "OFF" illuminated: The light is on to show that the system is currently deactivated. The engine will continue to run while you are stopped.
- Pressing the button again: You can press the button again to reactivate the system, which will then automatically turn the engine off and on as needed.
Reasons you might turn it off
- Personal preference: Some drivers find the frequent start-stop cycles to be inconvenient.
- Extreme weather: In very hot or cold weather, you may want the engine to stay on to keep the climate control working efficiently.
- Specific conditions: The system may also not engage if certain conditions are not met, such as if the battery is low or the cabin temperature hasn't been reached.
What is the a in a circle symbol on a car?
The "A" with a circle around it in a car is the Auto Start/Stop system, which turns the engine off when the vehicle is stationary to save fuel and reduce emissions. This button allows the driver to disable the feature, and the symbol on the dashboard may change color to indicate its status (e.g., green/blue for active, amber for disabled).
You can watch this video to learn what the A with a circle around it button does: 59sXJLuxuryYouTube · Mar 17, 2014
Function and usage
- Auto Start/Stop system: The system automatically shuts off the engine when you come to a complete stop (like at a traffic light) and restarts it as soon as you lift your foot off the brake pedal.
- Disabling the system: Pressing the button with the "A" in a circle will turn off the system, and the button will light up or the dashboard indicator will change, often to an amber color, to show it's off.
- Re-enabling the system: The system typically re-enables itself the next time you start the vehicle, though some systems may have to be manually turned back on.
Dashboard light
- System status: The symbol on the dashboard may appear as a solid "A" inside a circle with a green or blue light to show the system is working correctly.
- Fault or malfunction: If the light turns amber or shows an exclamation point, it may indicate a system malfunction or that the battery is low, as explained in this Reddit thread and this JustAnswer thread.
What is the light symbol with an A in it?
The engine stop-start light is typically an "A" surrounded by a circular arrow, and it can indicate a few different things. It may illuminate in a green or blue color to show that the system is active, or in an amber color to show that the system has been disabled.
