Lexus GS430 User Manual page 462

To initialize the system, perform the following:
1. Park the vehicle at a safe place and apply the parking brake.
Stop the engine.
2. Adjust the pressure of all the installed tires to the specified
level. (See "Tires and wheels" on pages 534 and 537.)
3. Start the engine.
4. Push and hold the reset switch until the low tire pressure
warning light blinks three times, and the message
"PRESSURE INITIAL" appears on the multi−information
display.
Do not turn the engine off for about 20 minutes until
initialization is complete.
STARTING AND DRIVING
G31007
When initializing the system, make sure the low tire pressure
warning light blinks three times and the message "PRESSURE
INITIAL" appears on the multi−information display. If the
warning light does not blink three times and the message does
not appear on the multi−information display, initialization failed
and the tire pressure warning system will not function properly.
In this case, initialize the system again.
Do not push the reset switch without adjusting the tire inflation
pressure to the specified level. Otherwise, the low 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.
If you push the reset switch while the vehicle is moving,
initialization is not performed.
If the low tire pressure warning light does not blink and the
message does not appear on the multi−information display
when you push and hold the reset switch, have the tire
pressure warning system checked at your Lexus dealer.
441