See also:

How to use the back button
Press the BACK button to return to the previous screen. ...

Clearing the programmed information
Individual buttons cannot be cleared, however to clear all programming, push and hold the two outside buttons and release when the indicator light begins to flash (in approximately 20 seconds) ...

Uniform tire quality grading
DOT (Department Of Transportation) Quality Grades: All passenger car tires must conform to federal safety requirements in addition to these grades. Quality grades can be found where applicable ...