2010 Toyota Highlander Owners Manual - Page 1455

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