Lexus 2012 RX450h Owner's Manual page 282

2-3. Operating the lights and windshield wipers
■
Rain-sensing windshield wipers
When
the sensor detects falling rain. The system automatically adjusts
wiper timing in accordance with rain volume and vehicle speed.
When
follows by turning the switch ring:
Type A
282
is selected, the wipers will operate automatically when
is selected, the sensor sensitivity can be adjusted as
Off
Rain-sensing wiper
operation
Low speed wiper
operation
High speed wiper
operation
Temporary operation