Lexus GS430 User Manual page 291

To prevent fogging up of the windshield, the air intake mode
may change automatically to the OUTSIDE AIR mode
depending on the condition of the air conditioning system.
For example, when the ambient temperature is low, the air
intake mode may change automatically to the OUTSIDE AIR
mode. This is not a malfunction.
When the air conditioning is on, if the engine coolant
temperature becomes extremely high, the RECIRCULATED
AIR mode is automatically selected. This is not a malfunction.
When the engine coolant temperature is lowered, the previous
mode resumes.
Turning off the air conditioning manually will cancel the
EXHAUST GAS AUTOMATIC mode. If you select the "AUTO"
mode during fan operating, the air conditioning turns on and
the EXHAUST GAS AUTOMATIC mode will operate.
For normal use, it is best to keep the air intake control button
set to OUTSIDE AIR mode. If recirculated air is used during
heating, the windows will fog up more easily.
To change the sensitivity of the sensor switching between
the RECIRCULATED AIR and OUTSIDE AIR in the
AUTOMATIC mode, push the air intake control button and
hold it for a few seconds. The display changes to the one
illustrated below.
The sensitivity of the sensor can be adjusted only while the
vehicle has been stopped.
G21023
The sensitivity of the switches is set to be higher toward "HI"
and lower toward "LO".
Touch the desired switch on the screen.
When you push any button except the air intake control button,
the above screen goes off.
AIR CONDITIONING
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