Traction Control System (TCS): Design & Working explained

What is the Traction Control System (TCS)?

TCS is an abbreviated of Traction Control System. As the name suggests, this system deals with controlling the traction of the drive wheels of the vehicle. The main purpose of employing this system is to control wheel slip occurring during acceleration on slippery roads. Traction Control System is always coupled with ABS and uses the hardware of ABS to function.

Hardware of TCS
Figure 1-Hardware of TCS(

Usually, it is experienced that the wheels of a vehicle spin on the same location without moving forward when accelerated on slippery roads like ice covered roads. This happens due to the reduced friction. In such a case, if the speed of rotation of that wheel lowers, then the wheel achieves its desired tractive force and can move forward under control. Thus, the role of the TCS begins here.

How the Traction Control System (TCS) works in a car?

Electronic Control Unit (ECU) having the module of Traction Control System in it; compares the rotational speeds of drive wheels of the vehicle with the help of the wheel speed sensors of ABS. If any of the drive wheels is rotating with exceptionally high speeds, then the TCS considers it as spinning of the corresponding wheel.

Working of traction control system
Figure 2- Working of traction control system (Courtesy- St. Louis RV)


The TCS, then, immediately sends a signal to apply brakes to that particular wheel. Thus, the traction control system avoids the wheel-slip; allowing the driver to accelerate under control.  There are some other ways also by which Traction Control System can avoid wheel spinning such as reducing the engine power delivered to the spinning wheel or cutting off the fuel supply to some engine cylinders etc.

A common misconception about the traction control system is that it prevents the wheel from sticking in the snow. But this is not true as the TCS does not have the ability to increase the wheel traction above its normal range. However, the use of TCS is especially useful for people driving on the snow-covered roads regularly.

Watch Mazda Traction Control system (TCS) in action:

Read on: How Electronic Stability Program works in a car?>>

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