What is traction, and what does traction control do on my car while I drive?
Traction is the grip that your cars tires have on the road, which is needed to accelerate, turn and brake. If your car, or more specifically, your tires have little or no grip; your car will not accelerate, turn or brake and will skid. Traction control devices in the car will help prevent this loss of grip so your tires will have traction to accelerate, turn and brake.
As marketed by most automakers, but related to ABS, is Traction Control. Traction Control is used to prevent the drive wheels from losing grip when accelerating. Spinning tires during hard acceleration may be dramatic, but it is the slowest way to get to your desired speed. Using the cars ABS speed sensors at the wheels, the Traction Control computer compares the drive wheels speed to the cars road speed. If there is a loss of grip event during acceleration, there are a number of ways that the Traction Control slows the drive wheels so they can regain grip. The most common method is to use the braking system. When the drive wheels lose grip, the ABS computer can apply the brake to the wheel that has lost grip to slow it down so it can regain grip. Another method for slowing the slipping wheels is to reduce the amount of power applied to them. The computer will electronically modify the amount of fuel entering the engine and/or use the transmission to slow the drive wheels so they can regain grip.
The latest traction control technology introduced to motor vehicles is Stability Control. While ABS and Traction Control help manage the grip of the tires for braking and accelerating, Stability Control helps prevent a car from sliding sideways. Using the same components in the ABS and Traction Control systems, Stability Control adds other sensors. These include; steering wheel angle sensor and yaw rate sensor. Yaw is defined as, "the movement of an object turning on its vertical axis. Stability Control is used to manage the amount of understeer a vehicle will exhibit if the driver used too much steering or entering a turn too fast. It will also manage oversteer if the driver uses too much or too little throttle while turning. Much like the other technologies of traction control, Stability Control will apply the brakes and/or throttle to a wheel or a number of wheels, independently, so the driver can regain control.
How does Stability Control help to regain control of the car? The foundation of ABS and Traction Control were already in place when Bosch pioneered Stability Control with their Electronic Stability Program (ESP) in the Mercedes Benz E Class in 1995.
