2010 Toyota Matrix Owners Manual - Page 163

2-4. Using other driving systems When VSC and TRAC are operating If the vehicle is in danger of slipping or the front wheels (2WD), or 4 wheels (AWD) spin, the indicator flashes to indicate that VSC/TRAC have been engaged. A buzzer (intermittent) sounds to indicate that VSC is operating. 2 When driving To disable TRAC and/or VSC If the vehicle gets stuck in fresh snow or mud, TRAC and VSC 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.