If you look around the dash of almost every modern vehicle, you will find a button that looks like a little car with skid lines trailing behind it. This is a button you never want to push.
Why? Hold it for a few seconds and it disengages electronic stability control - or ESC as it is commonly known. ESC is arguably the most important piece of safety technology to make its way into vehicles since the airbag.
ESC is a system that helps drivers keep control of their vehicle when it begins to lose traction, and since July 2015 has been mandatory on all new vehicles sold in New Zealand.
It is becoming progressively required on all used imports as well.
ESC is known by other names across vehicle brands - including automatic stability control, dynamic stability control, electronic stability control, vehicle dynamic control, vehicle stability control and vehicle skid control.
How does ESC work?
ESC uses a range of sensors in the vehicle to identify when it is not doing what the driver wants it to do, and assists in bringing the car back into line with where it thinks it should be going.
The three key sensors are steering wheel input, which tells the car where you intend it to go, a yaw sensor, which tells the car which direction it is actually going, and wheel speed sensors, which tell the car which wheels have traction on the road surface.
If the car’s computer calculates that any of those inputs are not correlating with the others, it will work to get things right again.
The systems can brake individual wheels to bring the car back into line. If for example the driver is turning left, but the car is going right, the system may slow selected wheels of the car to encourage it in the required direction. If the tail of a car is braking traction due to the application of too much power, it may reduce engine output.
Does ESC improve safety?
Massively. The NZ Transport Agency says international research shows the technology can reduce ‘loss-of-control’ accidents by 20-30%.
The amount of suffering the agency expects the technology to save is huge. Making it compulsory on cars is forecast to prevent 410 deaths and 1890 serious injuries over the next two decades. A further 22 lives will be saved, and 102 people spared from serious injury by making it compulsory on light commercials.
How can I tell if my car has ESC?
When buying a car, ask. It is often listed in the Trade Me Motors listing as well.
You can check your car for the aforementioned button, pictured in this story. Also when you turn on your car the same symbol should show on your dashboard, and switch off when the car is running. If it stays lit, it means there may be an error.
Should I ever turn ESC off?
On the road there is no good reason ever to turn ESC off. If you are using your car on a track then you may choose to give it a go, but the journalists here at Trade Me Motors keep it switched on unless we are in controlled conditions deliberately trying to lose traction.
Some sports-focussed vehicles have systems that will reduce the level at which ESC will intervene, but even these settings are best left for controlled conditions.