Air Mix Valve Position

The proper air mix valve position is determined by the heater and A/C programmer. In order to provide the proper mix of warm and cool air, the heater and A/C programmer monitors the following variables:
^ The set temperature
^ The coolant temperature
^ The ambient air temperature
^ The air delivery mode
^ The inside air temperature
^ The engine revolutions per minute (RPM)
^ The low side temperature
^ The blower speed
^ The sun load sensor
^ The mix motor feedback

The heater and A/C programmer position the air mix valve for the appropriate blend of air through the evaporator core and the heater core, depending upon the current program number.