What Is Traction Control and What Does It Do?

Doing doughnuts in an empty parking lot used to be a rite of passage for many new drivers. Front-wheel-drive cars made that more complicated but still possible. But now, thanks to traction control, those maneuvers are all but gone. What does traction control do? Why is it so prevalent in cars today? It’s more than just a buzzkill—this system can save your life.

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What is traction control?

Traction control prevents your tires from over-spinning as you accelerate. Using speed sensor data, the system detects when one wheel spins faster than the other and rapidly pulses the brake to slow the wheel rotation.

Bosch, an auto technology developer and manufacturer, invented traction control in 1985 to prevent avoidable accidents, making driving safer.

Before that, some rear-wheel-drive vehicles had mechanical systems that served a similar function, albeit in a rudimentary way. A limited-slip differential used a clutch system in the rear axle to split power between the rear wheels when one wheel started slipping.

What does traction control do?

The traction control module monitors input from speed sensors in the wheels, the differential, and/or the transmission and compares them. If the value from one or more sensors is faster than the car is physically traveling, the module identifies lost traction.

The traction control module works with the anti-lock brake system system and hydraulic brakes to rapidly pulse the brakes as many as 15 times per second. The module keeps working until you either let off the gas or your tires stop slipping.

Some vehicle systems will actually decrease the engine’s power to the slipping drive wheels to help you regain traction.

What can’t traction control do?

Traction control isn’t a cure-all for the things that can make you lose control. When engaged, the system only limits wheel spin. It does not improve road conditions, tire tread depth or inexperienced driving.

If you’re driving faster than the road conditions allow, traction control can’t suddenly cut through black ice or fix washboard gravel roads. Those outside conditions can still cause you to lose control and slide off the road, but you will do so in a straight line rather than spinning like a top.

Likewise, if you’re on ice with summer tires or bald tires, traction control won’t help you grip the surface. That’s why having the right set of tires is critical to driving your vehicle safely.

Traction control also can’t overcome inexperienced driving habits like hitting the throttle too hard or slamming on the brakes. While cars with traction control typically have anti-lock brakes, the traction control won’t help if your car is sliding.

Can you turn traction control on or off?

In most vehicles, there’s a button to toggle traction control on or off, or there might be a setting in the driver’s information display. When you cycle the ignition off and on, the traction control will be turned back on. Get to know your car’s features from the owner’s manual because there might be more than one setting for the traction control button.

For some cars, a single press turns traction control off. For others, you need to press and hold the button. Sometimes, a quick press turns off traction control while holding the button for a few seconds will turn off electronic stability control.

Reasons to turn traction control off

Although traction control can help you get traction in a straight line while you drive, it can’t help you much in other conditions.

If you get your car stuck in a snowdrift or loose sandy soil, traction control will keep your tires from spinning. That’s a problem if you’re trying to rock your car back and forth a few inches at a time to get out of a slippery situation. Turning the system off can be beneficial here.

If you’re driving up a steep hill or driveway when the surface isn’t ideal, you could lose momentum if your traction control kicks in. Pushing hard on the throttle with spinning tires could be the only way to get down the path without getting stuck.

You’ll also need to turn it off for activities like drifting, racing and just cranking doughnuts in a parking lot. Those activities require letting your tires break loose. These activities are also dangerous and not recommended without professional instruction and back-up safety mechanisms in place .

Is it safe to drive without traction control?

Yes, just less so. Most drivers over 40 recall driving a car without traction control. Most people would likely argue they drove safely.

Traction control is meant to assist the driver in safe operation on the road, and it definitely can help. For instance, have traction control on if:

• The roads are icy. Again, you can’t pulse the brakes on your own nearly as fast as the system can for you.
• You’re towing a heavy load uphill. If you’re pulling a trailer up a steep road or embankment, spinning tires can get you stuck.
• Your car is powerful. If your tires chirp every time you accelerate from a stop, traction control can help reduce tire wear.

Why is the traction control light on?

The traction control light usually comes on when the system is activated on a slippery surface. The light will also pop up with the other dashboard lights upon ignition, but it should go out a couple seconds later.

A traction control warning indicator that stays on signifies the system isn’t working as it should. Typical issues are faulty wheel speed sensors or damaged or worn-out wheel hubs with an integrated sensor. The system could also be broken or pinched—or have a corroded wire or a faulty computer module.

If your traction control light comes on and stays on, the system won’t work. Your wheels will spin as if the car isn’t equipped with the system. Stability control and ABS braking may not work, either. Driving a short while is probably fine if the conditions aren’t too bad, but you should have a mechanic diagnose and fix the issue before you get into trouble on the road.