Lexus GS430 User Manual page 472

STARTING AND DRIVING
CAUTION
Do not push the reset switch without first adjusting the
tire inflation pressure to the specified level. Otherwise,
the tire pressure warning light may not come on even if
the tire inflation pressure is low, or it may come on when
the tire inflation pressure is actually normal.
448
Tire pressure warning select switch
G31005a
" 1 Main position
2 2nd position
2 sets of tire pressure warning valve and transmitter ID codes
can be registered.
Once a second set of tires is registered at "2nd", you can switch
between tire set settings simply by pressing the tire pressure
warning select switch.
There are 2 settings
"MAIN" position: The ID code of the tire pressure warning valve
and transmitter on the tires originally installed on the vehicle is
registered.
" 2nd " position: The code is not registered. When you replace
a new set of tires, purchase tire pressure warning valves and
transmitters from your Lexus dealer and have the new ID code
registered by your Lexus dealer.