What Is The ACC Mode On Your Car's Ignition Switch?

Picture this — you're sitting in the airport parking lot waiting for a friend or loved one, fuming about all the gas you're wasting. Perhaps you're a new driver, or maybe you just never bothered to learn what the ACC mode is, but if you had, you'd be saving yourself a bit of frustration and a few dollars in gas money.

ACC stands for "Accessory Mode," and it's a function found in most modern cars. It allows drivers to use some ancillary services in their vehicle on battery power without actually turning on the ignition. For those of you that remember driving before push-button start, ACC mode is comparable to turning the key one click instead of two, or pushing the key to the left instead of the right.

In most modern cars with push-button start, you activate ACC mode by pressing on the start button without putting your foot on the brake pedal. You may have done this by accident and wondered why some functions lit up on your dashboard. ACC mode is not something you deploy when your vehicle is running, but it can be handy if you're stuck in your car with a long wait and don't want to be bored.

ACC Mode does not give you access to every function in your car. It has a limited scope, which unfortunately does not typically include air conditioning or heat, though it usually allows you to turn on the blower to circulate air. It typically gives you access to your power windows, your stereo, windshield wipers, and other peripheral components.

Open windows and some music can help make a long wait more comfortable, and you may even be able to charge your phone or set up your navigation while you wait. It's more environmentally-friendly and easier on your pocket than sitting with your engine idling, but the main disadvantage lies with extended use of ACC Mode, which can drain your battery. 

This won't happen immediately, and you're typically safe to use accessories via ACC Mode for a couple of hours. It's hard to imagine a situation where you'd want or need to use ACC Mode for longer than that, but just be aware that if you do, you may drain your battery to the point that your car may not start.

Most contemporary gasoline-powered cars have ACC Mode, but perhaps you're thinking about buying an electric vehicle or even a motorcycle. There does not seem to be a standard when it comes to accessory mode for EVs; some have them, some don't. In theory, an EV does not need accessory mode because everything already runs off on battery power. However, some models like the Kia EV6 still offer this tool.

Many motorcycles also offer an ACC Mode, including some Harley-Davidson models. This is an often-overlooked feature on Harley-Davidson bikes, and can be just as useful. It allows riders to keep the instruments on with the headlamp off to conserve battery power. Accessory mode on a Harley also allows the display of fuel information.

Whether you're driving a car or a motorcycle, an idling engine can drain your gas tank and cost you more than just a few pennies. The next time you're on pickup duty, ACC Mode may just make that wait a bit more bearable.