Thatcham -- Skoda Yeti -- PASS Thatcham is testing cars according to a global regulation to assess their Electronic Stability Control (ESC) systems. ESC automatically controls the vehicle by comparing the steering actions carried out by the driver to what the vehicle is actually doing. If the ESC senses that the vehicle is veering from the required course -- a skid -- it automatically brakes selected wheels to bring the car back into line. The test is a sine with dwell manoeuvre at 50mph and comprises a sinusoidal steer in one direction, followed by a steer in the opposite direction, with a dwell of 500 milliseconds at the second peak. It is controlled by a steering robot to give a precise and repeatable steering input, and the runs build up to a steering wheel angle of 270 degrees. ESC is often sold with different names: ESP, VSA, DSTC and others. For more information on ESC including Thatcham's dynamic testing and fitment information, please see www.thatcham.org/esc.