Air Mix Door Motor Circuit

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

Inspection Flow:

SYSTEM DESCRIPTION

Component Parts
Air mix door control system components are:
- Auto amp.
- Air mix door motor (LCU)
- In-vehicle sensor
- Ambient sensor
- Sunload sensor
- Intake sensor




System Operation
The auto amplifier receives data from each of the sensors. The amplifier sends air mix door, mode door and intake door motor opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor LCU.

The air mix door motor, mode door motor and intake door motor read their respective signals according to the address signal. Opening angle indication signals received from the auto amplifier and each of the motor position sensors are compared by the LCUs in each motor with the existing decision and opening angles. Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the auto amplifier.




Air Mix Door Control Specification

COMPONENT DESCRIPTION




Air Mix Door Motor
The air mix door motor is attached to the heater and cooling unit. It rotates so that the air mix door is opened or closed to a position set by the auto amplifier. Motor rotation is then conveyed through a shaft and the air mix door position is then fed back to the auto amplifier by PBR built-in air mix door motor.

DIAGNOSTIC PROCEDURE
SYMPTOM: Discharge air temperature does not change.
Perform diagnostic procedure for LAN system circuit. Refer to "LAN System Circuit".

AIR MIX DOOR




1. Install air mix door motor on heater unit and connect it to main harness.
2. Set up code No. 41 in Self-diagnosis STEP 4. Refer to "Self-diagnosis".
3. Move air mix door lever by hand and hold it in full cold position.
4. Attach air mix door lever to side link.




5. Make sure air mix door operates properly when changing from code No. 41 to 46 by pushing DEF switch.