DTC B1446/46: Air Mix Damper Control Servo Motor Circuit (Driver Side): Description

The air mix control servo motor sends pulse signals to indicate the damper position to the air conditioning amplifier. The air conditioning amplifier activates the motor (normal or reverse) based on these signals to move the air mix damper (driver side) to the appropriate position. This adjusts the amount of air passing through the heater core after passing the evaporator and controls the temperature of the blown air.

HINT: 

Confirm that there are no mechanical problems because this DTC can be set if either a damper link or damper is mechanically locked.