2012 Toyota Yaris Owners Manual - Page 143

2-4. Using other driving systems When the TRAC/VSC systems are operating The slip indicator light flashes to indicate that the TRAC/VSC systems have been engaged. 2 When driving Disabling the TRAC/VSC systems If the vehicle gets stuck in fresh snow or mud, TRAC/VSC systems may reduce power from the engine to the wheels. You may need to turn the system off to enable you to rock the vehicle in order to free it.