What is Accessory Mode on a Car?

February 6, 2024

The most common question we see regarding accessory mode is: “Does it drain your battery?” Essentially, the answer to this depends on your vehicle and how long you leave it in accessory mode. Typically, the accessory mode (which powers all electronics except for the engine) will turn off automatically once the battery is fully drained. However, if you don’t have the battery charged before using the accessory mode, you may risk damaging your car’s electronics and possibly ruining its battery.

To activate the accessory mode on your car, first press the start button without stepping on the brake pedal for auto transmission vehicles or with your brake pedal and the start button for manual transmission cars. You should hear 2 clicks — the first click turns on the accessories, while the second click shuts off the accessories. Then, you can press the start button again to start your engine.

Depending on how much you use the accessory mode, it can be a good way to stay entertained while waiting in a parking lot or even charge your phone. However, it’s recommended to limit your time in accessory mode to two hours maximum, as it can drain the battery.

What is Accessory Mode?

A car, or automobile, is a wheeled motor vehicle for the transport of people. It can seat one to eight people, and is usually propelled by a four-stroke gasoline or diesel engine. Other alternative fuels include electric power, hydrogen, and natural gas. The word car derives from the Latin “carrus” or “carro,” which means wagon. The term has also been used to describe a railway carriage that carries passengers, such as the French train de fer.


Traffic Dave is on a mission to help traffic engineers, transportation planners, and other transportation professionals improve our world.
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram