What Auto Start-Stop Does and Why You Might Disable It

Auto start-stop is a feature that automatically shuts off your engine when the car comes to a complete stop — at a red light, in traffic, or at a parking lot entrance — and restarts it when you press the accelerator or release the brake. The system is designed to reduce fuel consumption and emissions by eliminating the fuel burned during idle time.

Most cars built after 2015 come with this feature standard or as an option. Manufacturers including Ford, General Motors, BMW, Audi, Hyundai, and Toyota have all integrated versions into their lineups. The feature typically saves 3 to 5 percent on fuel economy in stop-and-go driving, though the actual savings depend on how much time you spend idling.

Some drivers disable it because they find the repeated engine shutdowns jarring, because they worry about starter wear, because the system drains the battery faster in certain conditions, or straightforward because they prefer the feel of a continuously running engine. The good news is that disabling it is usually straightforward and does not void your warranty or damage the vehicle.

Key Takeaways

  • Most vehicles let you turn off auto start-stop using a dashboard button, infotainment menu, or both, and the setting usually resets when you restart the car unless you save it as a preference.
  • The button is often labeled with a circular arrow or "A/S" symbol and sits on the dashboard, steering wheel, or center console depending on the make and model.
  • Some vehicles require you to navigate through the infotainment screen settings to disable the feature permanently, while others offer both a quick button and a menu option.
  • Disabling auto start-stop does not damage the engine, void the warranty, or trigger warning lights in most modern vehicles.
  • If your car does not have a visible button or menu option, the feature may be hardwired into the system and cannot be disabled without a dealer visit or aftermarket software.

Finding the Auto Start-Stop Button on Your Dashboard

The quickest way to disable auto start-stop is to locate the physical button. On most vehicles, this button sits on the dashboard to the left of the steering wheel, on the steering wheel itself, or on the center console near the gear shift. The button is typically marked with a circular arrow icon, sometimes with an "A" and "S" inside it, or labeled straightforward "A/S" or "Auto Stop."

Press the button once to turn off the feature. The dashboard will usually display a message confirming the change, and an indicator light will appear — often a green light next to the button or a message on the instrument cluster saying "Auto Start-Stop Off" or "A/S Disabled." This visual confirmation tells you the system is no longer active.

Keep in mind that on many vehicles, this setting does not persist after you turn off the engine. The next time you start the car, auto start-stop will be on again by default. If you want the setting to stay off every time you drive, you will need to save it as a preference through the infotainment menu instead.

Saving the Setting Through Your Infotainment Menu

To make the auto start-stop disable permanent, you usually need to access the vehicle settings menu on your infotainment screen. The exact path varies by manufacturer, but the general process is similar across most brands.

Start by pressing the "Menu" or "Settings" button on your infotainment system. Look for a submenu labeled "Vehicle Settings," "Driver Preferences," "Comfort Settings," or "Engine Settings." Once inside, search for an option called "Auto Start-Stop," "Start-Stop System," "Idle Stop," or "Engine Auto Off." Select it and choose "Disable" or "Off."

After you save the change, the system should remember your preference even after you turn off the car. Some vehicles also let you set different preferences for different driver profiles, so if multiple people drive the car, each person can have their own setting. Check your owner's manual for the exact menu path for your specific year, make, and model, since the naming and location of these menus differ significantly between manufacturers.

Manufacturer-Specific Steps for Common Brands

Ford vehicles typically have an A/S button on the dashboard or steering wheel. Press it to toggle the feature off. To save the setting permanently, go to Settings > Vehicle > Driver information > Auto Start-Stop and select Off.

General Motors vehicles (Chevrolet, GMC, Cadillac) usually display an A/S button on the instrument cluster or steering wheel. Press it to disable for that drive. To save it, navigate to Settings > Vehicle > Engine > Auto Start-Stop and turn it off.

BMW and Audi vehicles have the button on the center console or steering wheel. Press it to turn off the feature temporarily. To disable it permanently, access the iDrive or MMI menu, go to Vehicle Settings > Engine > Auto Start-Stop, and select Off.

Hyundai and Kia vehicles place the button on the dashboard or steering wheel. To save the setting, enter the infotainment menu, find Settings > Vehicle > Engine Management > Auto Start-Stop, and toggle it off.

Toyota vehicles typically have a button labeled "ECO" or "A/S" on the dashboard. Press it to disable the feature. Some Toyota models require you to access Settings > Vehicle > Engine > Idle Stop and select Off to make it permanent.

What Happens When You Disable Auto Start-Stop

Disabling auto start-stop does not trigger any warning lights, error codes, or dashboard alerts on modern vehicles. The system straightforward stops activating, and your engine will continue running normally at every stop, just as it did before auto start-stop became standard.

Your fuel economy will decrease slightly — typically by 2 to 5 percent in city driving — because the engine will now burn fuel during idle periods instead of shutting down. On the highway or in steady-state driving, you will see no difference in fuel consumption.

The starter motor will experience less wear because it will not be cycling on and off repeatedly throughout your drive. Some drivers report that disabling the feature also reduces strain on the battery, though modern vehicles are designed to handle the repeated starts without issue. Your warranty remains fully intact; disabling auto start-stop is an approved feature, not a modification.

When You Cannot Disable Auto Start-Stop

Some vehicles, particularly older models or certain trim levels, do not offer a way to disable auto start-stop through the dashboard or infotainment menu. In these cases, the feature is hardwired into the engine control module and cannot be turned off without professional intervention.

If you find yourself in this situation, your options are limited. You can visit a dealership and ask whether they can disable the feature through a software update or reprogramming, though this may cost between $100 and $300 depending on the manufacturer. Some independent mechanics and specialty shops also offer this service, sometimes at a lower cost.

Aftermarket solutions exist — devices that can be installed to trick the system into thinking the conditions for auto start-stop are not met — but these are not recommended because they can interfere with other engine management systems and may affect your warranty or emissions compliance.

Frequently Asked Questions

Will disabling auto start-stop damage my engine or starter?

No. Modern starters are engineered to handle thousands of starts, and disabling auto start-stop straightforward returns your engine to the way it operated before the feature became standard. Your starter will actually experience less wear because it will not cycle as frequently.

Does turning off auto start-stop void my warranty?

No. Disabling auto start-stop is an approved feature on every vehicle that offers it. Manufacturers expect some drivers to turn it off, and doing so does not void any part of your warranty.

Why does my auto start-stop setting reset every time I start the car?

Your vehicle is likely set to use the temporary disable button rather than a saved preference. Access your infotainment menu and look for a permanent disable option in the vehicle settings or driver preferences section. This will keep the feature off even after you restart the engine.

Can I disable auto start-stop on an older car that has it?

If your car has a physical button or infotainment menu option, yes. If it does not, you will need to visit a dealership or specialist shop to have it disabled through software reprogramming, which typically costs $100 to $300.

Does disabling auto start-stop affect my emissions or fuel economy significantly?

Your fuel economy will drop by 2 to 5 percent in city driving where you spend time idling, but highway fuel economy will remain unchanged. Emissions will increase slightly during idle periods, but the difference is minimal and does not affect your vehicle's emissions compliance.