Traction Control And Stability Control: What's The Difference?

by Cobus F. Potgieter /

4.5

(183)

It's all about keeping your grip - but they're not the same thing.

Read in this article:

What Is Electronic Stability Control, Or ESC, On A Car?
Stability Control vs Traction Control
What Is An ESP System - or ESC, DSC, VSA, or VSC?
Pros And Cons Of TCS And ESC
Conclusion
FAQs

What Is Electronic Stability Control, Or ESC, On A Car?

ESC stands for Electronic Stability Control - a generic term widely used in the industry and the default term we will use for all types of stability control in this article. But what is ESC - or electronic stability control - on a car? It is a control system reading inputs such as vehicle speed, steering angle, yaw, and individual wheel speed received from various sensors. If the inputs suggest that the driver is losing directional control of the vehicle and may skid - in other words, not go in the direction they want to go and in which the steering wheel is pointed - it can intervene to get the car back on course.

The most common types of loss of directional control are:

Wheel lockup. In a car without ABS, the wheels lock up under braking, causing the car to skid in the direction its momentum is taking it, regardless of steering input. The ABS system pulses the braking system rapidly to keep the wheels rotating just shy of lockup to retain some steering control.
Understeer. While going around a corner, the car plows straight on, the front wheels slipping instead of turning in as sharply as the driver had intended. ESC brakes the inside rear wheel, which pulls the nose into the corner and reduces the understeer.
Oversteer. The rear of the car skids outward and the vehicle turns in sharper than the driver intended, the nose pointing to the inside of the curve instead of down the road. ESC brakes the outside front wheel to prevent the car from rotating, arresting the oversteer.

Various combinations of these three scenarios can occur. Sometimes ABS intervention is all that's needed to prevent a skid under braking and sometimes the ESC must also intervene to maintain directional stability around a corner. These systems work seamlessly and in tandem to keep the vehicle stable. Simpler ESC systems control the brakes only and more advanced ones can also reduce the engine's torque to take excess power away from the drive wheels for a finer measure of control.

Stability Control vs Traction Control

You might have heard of a traction control system (TCS) and think it's the same as stability control. It isn't. When it comes to a comparison of traction control vs stability control, TCS is a far simpler system. But what does TCS mean on a car? And what does traction control actually do? It uses the ABS system in reverse to check whether a wheel is spinning under power, causing a loss of accelerative traction. If it identifies a spinning wheel, it brakes that wheel to restore its traction. It cannot detect yaw, oversteer, or understeer, as ESC can, only wheelspin.

Because it is a far more basic system, many older cars have it, even if they don't have ESC. The converse isn't true and it is basically a given that, if a car has ESC, traction control will be present too. Therefore, saying your car has ESC or ESP while meaning TCS is usually correct, but the opposite isn't.

What Is An ESP System - or ESC, DSC, VSA, or VSC?

These are synonyms for ESC. So what is ESP and what does ESP stand for? It stands for Electronic Stability Program, just another name for stability control. The car industry and different automakers give their branded versions or types of ESC/ESP systems different names.

Here are a few examples used over the years:

ESC means Electronic Stability Control (widespread generic term)
ESP means Electronic Stability Program (often, not always, the Bosch-based version)
DSC means Dynamic Stability Control (typically BMW's Bosch/Teves system)
VSA means Vehicle Stability Assist (Acura/Honda)
VSC means Vehicle Stability Control (Toyota/Lexus)
VDC means Vehicle Dynamic Control (Alfa Romeo, Infiniti)
DSTC means Dynamic Stability and Traction Control (Volvo)
MSP means Maserati Stability Program
PSM means Porsche Stability Management
StabiliTrak (GM/Delphi)
AdvanceTrac (Ford/Lincoln)

Pros And Cons Of TCS And ESC

Consider the main advantages of TCS and ESC:

Maintaining vehicle control
Preventing accidents
Reducing the severity of accidents when they happen
Fewer accidents mean less property damage
Saving the lives of pedestrians and cyclists thanks to better avoidance
Reducing tire wear and tear

These systems have very few disadvantages:

They will not improve the track times of skilled drivers
They can sometimes interfere with off-road driving
They increase the prices of new cars, but economies of scale minimize the effect

Conclusion

All new cars sold in the US since 2012 must be fitted with ESC as standard. NHTSA data has shown that ESC saves thousands of lives on American roads every year and it is often lauded as the biggest advancement in automotive safety after the three-point seatbelt and crumple zones. Next time you feel the brakes subtly tugging on your car around a corner or the ESC light winking at you in the instrument panel, spare a moment to realize that, 20 years ago, that moment could have ended in a crash.

Just remember that these systems cannot overcome the laws of physics and safe driving is first and foremost the driver's responsibility. Vehicle maintenance is also important and worn suspension components or tired shocks may cause a loss of control regardless and may cause these systems to cut in more frequently to keep you on the road, eroding your margin for error.

FAQs

What is the traction control light’s meaning?

If the traction control's light flickers momentarily while driving, it means that the system has activated and stopped a wheel from spinning. If the light stays on all the time, it means that there is something wrong with the system and it needs to be repaired. A good example is the VSA light remaining on in certain Honda Accord models.

What does Service Traction Control mean and how do I fix the traction control light?

If the Service Traction Control message comes up, the warning light will illuminate as an indicator and reminder that the system has developed a fault, may not work, and has to be repaired. The only way to make the light go away is to have the system fixed by an authorized mechanic, preferably at one of your OEM's dealers. They will diagnose the problem, replace the necessary parts, and reset the light so that it stays off. Don't ignore an illuminated traction or stability control light.

If something is wrong with it, can you tell me how to fix my traction control system?

There are virtually no serviceable parts that normal vehicle owners are qualified to work on in a traction control system. You can have a look at the fuses and replace a blown one if that is the problem. If an ABS wheel-speed sensor has become dirty, it might disable the traction control and ABS and sometimes a thorough hosing down of the wheels and brakes can clear it. This is about as much as you can do. It's best to just leave these systems' diagnosis and repairs to the professionals.

Can I turn my car’s ESP off?

On some vehicles, the ESP can be turned off. In most cases, these are sports cars such as the Toyota Supra or GR 86. Owners of such specialist cars want to take their cars to the limits on a race track and don't want electronic systems interfering with the handling, since they are trying to improve their own car-control skills. Such cars usually have a button on the dash to turn the ESC off, and this will typically permanently illuminate the ESC OFF light to remind the driver that the system is disabled. This illuminated icon varies by car and may be a warning triangle or a graphic of a vehicle skidding - or both. Keep in mind that driving on a race track or turning off your ESC may invalidate your insurance.

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