Air Flow Control

SYSTEM

REAR AUTOMATIC AIR CONDITIONING SYSTEM : Air Flow Control


DESCRIPTION

- A/C auto amp. changes duty ratio of rear blower motor drive signal and controls air flow continuously. When air flow is increased, duty ratio of rear blower motor control signal gradually increases to prevent a sudden increase in air flow.
- In addition to manual control and automatic control, air flow control is compose of starting fan speed control, low coolant temperature starting control, high in-vehicle temperature starting control and fan speed control at door motor operation

AUTOMATIC AIR FLOW CONTROL

- A/C auto amp. decides target air flow depending on target rear air mix door opening angle.
- A/C auto amp. changes duty ratio of rear blower motor control signal and controls the air flow continuously so that air flow matches to target air flow.





- When air outlet is VENT or B/L, the minimum air flow is changed depending on sunload.

STARTING AIR FLOW CONTROL






- When rear blower motor is activated, A/C auto amp. gradually increases duty ratio of rear blower motor control signal to prevent a sudden increase in discharge air flow.
- It takes approximately 8 seconds for air flow to reach HI from LOW.

LOW COOLANT TEMPERATURE STARTING CONTROL






If the engine coolant temperature is 56�C (133�F) or less, to prevent a cold discharged air flow, A/C auto amp. suspends rear blower motor activation for the maximum 150 seconds depending on target rear air mix door opening angle. After this, rear blower motor control signal is increased gradually, and rear blower motor is activated.

HIGH IN-VEHICLE TEMPERATURE STARTING CONTROL

When front evaporator fin temperature is high [intake sensor value is 35�C (95�F) or more], to prevent a hot discharged air flow, A/C auto amp. suspends rear blower motor activation for approximately 3 seconds so that rear evaporator is cooled by refrigerant.

FAN SPEED CONTROL AT DOOR MOTOR OPERATION

When rear mode door motor is activated while air flow is more than the specified value, A/C auto amp.
reduces temporarily fan speed so that rear mode door moves smoothly.