Traction control is one of the most important safety features fitted to modern vehicles. It helps your car maintain grip on the road, supports safe driving and prevents the wheels from spinning when driving on slippery surfaces.

The traction control system in modern cars works alongside the braking system and engine management to keep the vehicle stable in poor driving conditions.

What is traction control?

Traction control is an active safety system designed to prevent wheel spin and improve vehicle stability.

It works by monitoring the speed of each wheel and adjusting braking or engine power when one wheel loses grip.

The main purpose of traction control for slippery roads is to help drivers maintain control when driving on surfaces such as:

• Ice
  
  
• Snow
  
  
• Wet roads
  
  
• Mud
  
  
• Sand
  
  
• Loose gravel

What does traction control do?

Your vehicle's traction control system helps maintain drive power and prevent your wheels slipping on mud, ice, sand, or dirt, by sensing the acceleration of each wheel.

The traction control system can also help reduce or eliminate slipping/skidding while cornering.

How does traction control work?

If three wheels are moving as expected but one is slipping, traction control works with the ABS system to brake the slipping wheel, so that the vehicle can proceed safely.

The system pulses the brakes to slow down the slipping wheel, providing more overall traction on the road surface.

How to use traction control: Should you use traction control all of the time?

Traction control is undeniably a highly effective safety feature, but it might not be suitable to have switched on all the time.

Example of when traction control is not suitable

If you are stuck on a patch of mud or snow, you may need to rock the vehicle back and forth in order to gain traction. However, with traction control turned on, this is not possible.

This issue is further discussed below.

How do you switch traction control on and off?

Your traction control system is operated with a button with an icon of a car above wavy wheel tracks.

What does ‘TC’ mean on a car?

On some vehicles, the traction control on/off switch may simply be marked with a ‘TC’.

Most switches also feature a traction control light to show when the traction control system is in operation.

How to turn off traction control?

Simply press the traction control button so that it pops out and the light goes off.

If you are in any doubt as to the operation of your vehicle's traction control system, check the manual.

If you have lost the manual, you should be able to download a digital PDF version from the manufacturer.

Traction control history

The original, if primitive, version of the traction control system was the ‘limited slip differential’, which was introduced in the 1960s. However, this system could not completely eliminate wheel slippage.

Then the Buick Car Company introduced a more sophisticated computer-managed system that detected wheel slips and modulated engine power accordingly - way back in 1971.

Later, in 1979, a "traction monitoring system" was introduced by Cadillac.

Traction Control and the ABS System

Traction control is closely related to the ABS system, and many vehicles use shared components.

Understanding the difference between ABS and traction control helps explain how both systems improve safety.

• ABS (Anti-lock Braking System) prevents wheels from locking during braking.
  
  
• Traction control prevents wheels from spinning during acceleration.
  
  

Both systems work together to maximise tyre grip and maintain vehicle control.

How does the traction control system work in modern vehicles?

In modern vehicles, the ABS and the traction control are considered part of the same system.

The wheel speed sensors detect the speed of the wheel and communicate this to the ECU.

If the system determines that one wheel is spinning faster than the others, the ECU takes over the hydraulic control unit, then applies the brakes intermittently to control the slipping wheel. This then gives the vehicle more overall traction on slippery surfaces.

Wheel speed sensors on two-wheel-drive vehicles

In the case of two-wheel-drive vehicles, wheel speed sensors are usually only connected to the wheels receiving power.

Managing slippage with engine power

In some vehicles, the traction control system can manage wheel spin by reducing engine power. This can be effected either by:

● Retarding the ignition timing
● Reducing the fuel supply to the cylinders
● Closing the throttle

When any of the above happen, the driver may sense some pulsing vibrations through the acceleration pedal.

Improved cornering with traction control

Traction control systems can also help maintain control around corners.

How does traction control help improve cornering?

When cornering, the outer wheels spin faster than the inner wheels, because they have to cover more distance in the same time frame.

Without traction control, when the driver applies more throttle while cornering, the wheels may slide. However with traction control on, slipping wheels are controlled, preventing the vehicle from slipping/skidding.

When is traction control activate when cornering?

Traction control is activated when the speed of the wheels is mismatched with the overall acceleration of the vehicle.

When traction control is undesirable?

Standing starts

There are certain scenarios where traction control is not desirable. For example, if your vehicle is at a standstill on a slippery surface, traction control may reduce engine power to the degree that it is difficult to gain enough traction to move off.

In such circumstances, you can turn off the traction control.

What if I cannot turn off my traction control?

In some vehicles traction control cannot be completely deactivated, but it may permit an increase in wheelspin under such conditions as a standing start.

When to use traction control?

Wondering, should traction control should be on or off?

Whether or not you decide to use traction control may depend on your driving style, as well as:

● The weather conditions
● The quality of the road surface
● Type of tyres
● Whether you have front-wheel-drive, rear-wheel-drive, or all-wheel-drive

However, if in doubt, try moving off with traction control switched on.

Wheel spin: Front, rear and all-wheel-drive

In general, front-wheel-drive vehicles experience a higher degree of wheel spin than those with rear-wheel-drive (unless the rear-wheel-drive system in question has a high torque engine).

Vehicles with all-wheel-drive and traction control can get better traction on slippery surfaces.

Service traction control/traction control warning light

The ‘service traction control’ warning light will come on if the car detects a fault with any of the TCS apparatus - such as a damaged wheel speed sensor, or a problem with the ABS.

What happens if there is a fault in the traction control apparatus?

If any of these components are not working properly, the car’s traction control may not work properly - potentially putting you, your passengers and other road users in danger.

Launch control systems

Some premium vehicles feature launch control systems, which support a controlled, safe launch from standstill. However, these are normally only found in high performance/race/rally cars.

Electronic Stability Control and StabiliTrak

Traction control is also closely related to Electronic Stability Control (ESC) systems.

These systems help prevent loss of control during sudden manoeuvres.

For example:

• StabiliTrak, developed by General Motors
  
  
• ESP (Electronic Stability Program) used by Audi
  
  
• AdvanceTrac used by Ford
  
  

ESC systems use additional sensors such as:

• Steering angle sensors
  
  
• Vehicle rotation sensors
  
  
• Lateral acceleration sensors
  
  

These sensors allow the system to detect when a car begins to skid and apply corrective braking.

Need Help on the Road?

Even the safest cars can break down unexpectedly. If you experience problems with your ABS system, traction control, or other safety features, having breakdown cover can provide peace of mind.