Air Mix Door Motor Circuit

Air Mix Door Motor Circuit

SYMPTOM:
- Discharge air temperature does not change.
- Air mix door motor does not operate.

Inspection Flow:

INSPECTION FLOW

SYSTEM DESCRIPTION

Component Parts
Air mix door control system components are:
- Front air control.
- Air mix door motors (Driver, Passenger, and rear)
- PBR (built-into air mix door motors)
- In-vehicle sensor
- Ambient sensor
- Optical sensor
- Intake sensor

System Operation

The front air control receives data from the temperature selected by the driver side, passenger side, and rear. The front air control then applies a voltage to one circuit of the appropriate air mix door motor, while ground is applied to the other circuit, causing the appropriate air mix door motor to rotate. The direction of rotation is determined by which circuit has voltage applied to it, and which one has ground applied to it. The front air control monitors the air mix door positions by measuring the voltage signal on the PBR circuits of each door.

In AUTO mode the air mix, intake, mode door, and defrost door positions are set by the front air control which determines the proper position based on inputs from the in-vehicle sensor, ambient sensor, optical sensor, intake sensor, and the temperature selected by the driver and front and rear passengers.

Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new door position data is returned to the front air control.

Air Mix Door Control Specification:

Air Mix Door Control Specification

COMPONENT DESCRIPTION

Air Mix Door Motors

The driver and front passenger air mix door motors are attached to the front heater & cooling unit assembly. The rear air mix door motor is attached to the rear heater & cooling unit. These motors rotate so that the air mix door is opened or closed to a position set by the front (or rear) air control. Motor rotation is then conveyed through a shaft and the air mix door position is then fed back to the front air control by the PBR built into the air mix door motors.