Air Flow Control
DESCRIPTION
- A/C amp. changes duty ratio of front blower motor control signal and controls air flow continuously. When air flow is increased, duty ratio of front 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 blower speed control at door motor operation and fan speed control at voice recognition.
AUTOMATIC AIR FLOW CONTROL
- A/C amp. decides target air flow depending on target air mix door opening angle.
- A/C amp. changes duty ratio of front blower motor control signal and controls 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 FAN SPEED CONTROL
When front blower motor is activated, A/C amp. gradually increases voltage of front blower motor to prevent a sudden increase in discharge air flow. (T1 – T2 = approximately 8 seconds)
note | Do not perform the starting air flow control when the air outlet is set to DEF. |
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 amp. suspends front blower motor activation for the maximum 150 seconds depending on target air mix door opening angle. After this, voltage of front blower motor is increased gradually, and front blower motor is activated.
HIGH IN-VEHICLE TEMPERATURE STARTING CONTROL
When evaporator temperature is high [intake sensor value is 35°C (95°F) or more], to prevent a hot discharged air flow, A/C amp. suspends front blower motor activation for approximately 3 seconds so that evaporator is cooled by refrigerant.
FAN SPEED CONTROL AT DOOR MOTOR OPERATION
When mode door motor is activated while air flow is more than the specified value, A/C amp. reduces temporarily fan speed so that mode door moves smoothly.
FAN SPEED CONTROL AT VOICE RECOGNITION
When the voice control (voice command) switch is operated during air flow automatic control, A/C amp. decreases the air flow of the front blower motor once and controls the air flow so as not to disturb the voice recognition function. This control continues while voice recognition function is operating.