Toyota Lexusc Owner's Handbook Manual page 298

"DUAL" button —
This switch is used to set the temperatures independently for
the driver's seat and front passenger seat.
Pushing the button changes the mode from independent and
linked.
D Independent
mode: Temperatures
independently for the driver's seat and front passenger's
seat. The indicator light will illuminate to show that the
independent mode has been selected. The indicator light
will come on to show that the independent mode has been
selected.
D Linked mode: The same temperature is set for the driver's
seat and front passenger's seat. The indicator light will turn
off to show that the simultaneous temperature setting mode
has been selected.
When the temperature for the front passenger's seat is
changed in linked mode, the mode is changed automatically to
can be set independent mode.
AIR CONDITIONING
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