When the VSC/TRAC or Active TRAC/hill-start assist control systems are operating
If the vehicle is in danger of slip- ping or rolling backward when starting on an incline, or if any of the drive wheels spins, the slip indi- cator light flashes to indicate that the VSC/TRAC or Active TRAC/ hill-start assist control systems are operating.
A buzzer (intermittent) sounds to indicate that VSC is operating.
The stop lights and high mounted stoplight turn on when the hill-start assist control system is operating.

See also:
Additional Coverage
After your roadside assistance coverage expires, you may join a motor club created
exclusively for Lexus owners. Benefits include roadside assistance coverage, a trip-planning
service and discount ...
Front passenger occupant classification system
Your vehicle is equipped with a front passenger occupant classification system.
This system detects the conditions of the front passenger seat and activates
or deactivates the devices for the front ...
Tires and wheels
...
