Air Mix Door Motor Circuit
Air Mix Door Motor CircuitSYMPTOM:
- Discharge air temperature does not change.
- Air mix door motor does not operate.
Step 1-8:
Step 8 (Continued)-12:
INSPECTION FLOW
SYSTEM DESCRIPTION
Component Parts
Air mix door control system components are:
- Unified meter and A/C amp.
- Air mix door motor (LCU)
- A/C LAN system (PBR built-into mode door motor, intake door motor and air mix door motor)
- In-vehicle sensor
- Ambient sensor
- Sunload sensor
- Intake sensor
System Operation
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp. 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 unified meter and A/C amp. 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 unified meter and A/C amp.
Air Mix Door Control Specification
COMPONENT DESCRIPTION
Air Mix Door Motor
The air mix door motor is attached to the heater and cooling unit assembly. It rotates so that the air mix door is opened or closed to a position set by the unified meter and A/C amp. Motor rotation is then conveyed through a shaft and the air mix door position is then fed back to the unified meter and A/C amp. by PBR built-in air mix door motor.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
Perform diagnostic procedure for LAN circuit. Refer to ATC-45, "LAN System Circuit". LAN System Circuit