How Does ESC Work?

Watch the 2 videos of ESC use / not used in a dangerous avoidance scenario (1 minute)


The ESC (Electronic Stability Control) system is controlled by an on-board computer that detects when the car is not taking the path that the driver intended, for example during oversteer and understeer. On board sensors measure the speed, steering wheel angle, direction of travel and lateral acceleration of the vehicle. If the calculated path of travel is different to that dictated by the steering wheel position, the stability control computer will make a correction. The brakes on individual wheels are automatically applied, just enough to correct this deviation but not enough to alert the driver. The computer decides which brakes to apply to make the most effective combination, all independent of the driver. In some cases, the stability control program may also reduce the engine power. When the ESC system is intervening a warning light on the dashboard — normally orange in colour, will illuminate momentarily. It will not stay on permanently.

The majority of cars are fitted with an ESC switch, which can be used to switch the ESC off when certain unusual road conditions are encountered - like moving off in deep snow. ESC is by default switched ON when you start your vehicle, so it does not require switching on. ESC is a major safety feature and could save your life. Do not touch your ESC button, unless those specific conditions are encountered. For further information, please consult your vehicle handbook.