2010 Toyota Highlander Owners Manual - Page 251

2-4. Using other driving systems When the VSC/TRAC systems are operating If the vehicle is in danger of slipping, rolling backwards when starting on an incline, or the four wheels spin, the indicator flashes to indicate that the VSC/TRAC systems have been engaged. ● ABS: The slip indicator light flashes when ABS is operating. ● VSC: A buzzer (intermittent) sounds to indicate that VSC is operating.