Toyota Lexusc Owner's Handbook Manual page 73

SWITCHES
Twist the knob to the second clickstop to turn on the headlights
to full intensity for driving at night.
When setting the knob to the third clickstop ("AUTO"), the
headlights will automatically adjust to full intensity and/or turn
on the other lights depending on the darkness of the
surroundings. Likewise, as the surroundings become brighter,
the headlights will turn to reduced intensity, ultimately turning
off the other lights.
NOTICE
To prevent the battery from being discharged, do not
leave the lights on longer than necessary when the
engine is not running.
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