ELECTRONIC STABILITY CONTROL (ESC)
Electronic Stability Control puts safety first in all critical situations by automatically applying the brakes on individual wheels to keep the vehicle heading in the right direction. (In fact, ESC is a function of the ABS control unit—more on that below.) Whether it's an elk in the middle of the road or some other unforeseen event, ESC helps you to maintain better control and stay on track when you are forced to make an evasive manoeuvre.
ESC builds on other electronic systems, such as the anti-lock braking system (ABS) and ASR traction control system. It takes driving safety a step further—controlling lateral dynamics and helping to prevent oversteering or understeering by applying corrective forces to each of the wheels.
These braking interventions are performed almost instantly and last only a fraction of a second. The brain controlling the interventions is the system computer that receives information from a yaw rate sensor on whether and how the vehicle is rotating about its vertical axis. Other sensors also supply important data to the computer: a steering angle sensor, a lateral acceleration sensor and four wheel sensors. Using the data from these sensors, the system computer detects any differences between target values and actual values, and acts as an electronic guardian angel, initiating the necessary
TRACTION CONTROL (ASR)
For high-torque engines, traction control offers more comfort and safety, particularly when driving on slippery roads or surfaces with differing degrees of grip. The traction control system facilitates smooth starting and acceleration over the entire speed range, without wheelspin or fishtailing.
The traction control system operates in tandem with the electronic accelerator (EGas) and uses the wheel speed sensors of the anti-lock braking system (ABS). If a sudden increase in speed is detected at one of the drive wheels, the traction control intervenes in the engine management system to counter this effect by throttling back engine power.
Traction control assures good traction and directional stability in the acceleration phase across the entire speed range, and thus promotes active safety. In addition, it reduces tire wear. Traction control also incorporates the electronic differential lock (EDL) and makes up part of the electronic stabilization program (ESP).