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:
What types of decisions are rendered, and how do I know if Lexus will abide
by the decision of the arbitrator(s)?
Arbitrated decisions are based on what the arbitrator(s) believe to be fair and
equitable after applying the appropriate legal standards. Remedies include but are
not limited to repairs; reimburse ...
If You Need Assistance
Both Lexus and your Lexus dealer are dedicated to serving your automotive needs.
Your complete satisfaction is our first priority. Should you have a problem or concern,
please take the following s ...
Vehicle customization
Vehicle settings can be changed.
1. Push the “SETUP” button.
2. Touch “Vehicle” on the “Setup” screen.
3. Touch “Vehicle Customization”.
4. Select the setting to be changed.
V ...
