AIR CONDITIONING SYSTEM


  1. FUNCTION OF MAIN COMPONENTS


    1. The air conditioning system consists of the following parts:

      Models with Manual Air Conditioning System
      Component Function
      Air Conditioning Control Assembly Allows operation and adjustment of the air conditioning system via switches.
      Air Conditioning Amplifier Assembly Transmits and receives data between the switches and sensors.
      Compressor with Pulley Assembly Performs suction, compression and discharge of refrigerant gas.
      Blower Motor with Fan Sub-assembly High magnetic force magnets and ball bearings are used to achieve a compact and lightweight assembly.
      Cooler Condenser Assembly A condenser is used to improve heat exchange efficiency.
      Heater Radiator Unit Sub-assembly A Straight Flow Aluminum (SFA)-II heater radiator is used for compactness and high performance.

      No. 1 Air Conditioning Radiator Damper Servo Sub-assembly


      • Damper Servo (Mode Switching)

      • Damper Servo (Air Mix)


      • Controlled by the air conditioning amplifier assembly to move the mode control damper and switch the registers.

      • Controlled by the air conditioning amplifier assembly to move the air mix control damper.

      No. 2 Air Conditioning Radiator Damper Servo Sub-assembly


      • Damper Servo (Rear Mode Switching)

      Driven by the air conditioning amplifier assembly to move the rear mode control damper.

      No. 1 Blower Damper Servo Sub-assembly


      • Damper Servo (Fresh/Recirculation)

      Driven by the air conditioning amplifier assembly to move the fresh/recirculation damper.
      Evaporator Temperature Sensor (No. 1 Cooler Thermistor) Detects the temperature of the cool air past the No. 1 cooler evaporator sub-assembly and transmits the data to the air conditioning amplifier assembly.
      Ambient Temperature Sensor (Thermistor Assembly) Detects ambient temperature and outputs it to the air conditioning amplifier assembly.
      Air Conditioner Pressure Sensor Detects the refrigerant pressure and outputs data to the air conditioning amplifier assembly.
      ECM Receives the signals from the engine coolant temperature sensor and transmits them to the air conditioning amplifier assembly.
      Main Body ECU (Multiplex Network Body ECU) Receives the signals from the automatic light control sensor and transmits them to the air conditioning amplifier assembly.
      Models with Automatic Air Conditioning System
      Component Function
      Radio and Display Receiver Assembly Allows operation and adjustment of the air conditioning system via switches.
      Cooler Control Switch Assembly*1
      Air Conditioning Amplifier Assembly Transmits and receives data between the switches and sensors.
      Compressor with Pulley Assembly Performs suction, compression and discharge of refrigerant gas.
      Blower Motor with Fan Sub-assembly High magnetic force magnets and ball bearings are used to achieve a compact and lightweight assembly.
      Cooler Condenser Assembly A condenser is used to improve heat exchange efficiency.
      Heater Radiator Unit Sub-assembly A Straight Flow Aluminum (SFA)-II heater radiator is used for compactness and high performance.

      No. 1 Air Conditioning Radiator Damper Servo Sub-assembly


      • Damper Servo (Mode Switching)

      • Damper Servo (Driver Seat Air Mix)

      • Damper Servo (Front Passenger Seat Air Mix)


      • Controlled by the air conditioning amplifier assembly to move the mode control damper and switch the registers.

      • Controlled by the air conditioning amplifier assembly to move the driver seat air mix control damper.

      • Controlled by the air conditioning amplifier assembly to move the front passenger seat air mix control damper.

      No. 2 Air Conditioning Radiator Damper Servo Sub-assembly


      • Damper Servo (Rear Mode Switching)

      Driven by the air conditioning amplifier assembly to move the rear mode control damper.

      No. 3 Air Conditioning Radiator Damper Servo Sub-assembly*1


      • Damper Servo (Rear Air Mix)

      Controlled by the air conditioning amplifier assembly to move the rear air mix control damper.

      No. 1 Blower Damper Servo Sub-assembly


      • Damper Servo (Fresh/Recirculation)

      Driven by the air conditioning amplifier assembly to move the fresh/recirculation damper.
      Evaporator Temperature Sensor (No. 1 Cooler Thermistor) Detects the temperature of the cool air past the No. 1 cooler evaporator sub-assembly and transmits the data to the air conditioning amplifier assembly.
      Ambient Temperature Sensor (Thermistor Assembly) Detects ambient temperature and outputs it to the air conditioning amplifier assembly.
      Cooler (Room Temperature Sensor) Thermistor Detects room temperature and outputs it to the air conditioning amplifier assembly.
      Automatic Light Control Sensor Detects the changes in the amount of solar energy and outputs them to the air conditioning amplifier assembly via the main body ECU (multiplex network body ECU).
      Air Conditioner Pressure Sensor Detects the refrigerant pressure and outputs data to the air conditioning amplifier assembly.

      Electric Parking Brake Switch Assembly*2


      • ECO Switch

      Transmits the ECO switch on signal to the air conditioning amplifier assembly.
      ECM Receives the signals from the engine coolant temperature sensor and transmits them to the air conditioning amplifier assembly.
      Combination Meter Assembly Transmits the vehicle speed signal and front passenger presence signal to the air conditioning amplifier assembly.
      Airbag Sensor Assembly Transmits the front passenger seat occupant status signal to the air conditioning amplifier assembly.
      Main Body ECU (Multiplex Network Body ECU) Receives the signals from the automatic light control sensor and transmits them to the air conditioning amplifier assembly.

      *1: Models with 3-zone control

      *2: Models with drive mode select switch

  2. SYSTEM CONTROL


    1. Control List

      Control Outline Type
      Automatic Air Conditioning Manual Air Conditioning
      Neural Network Control This control is capable of effecting complex control by artificially simulating the information processing method of the nervous system of living organisms in order to establish a complex input/output relationship that is similar to a human brain. -
      Outlet Air Temperature Control In compliance with the temperature set at the temperature setting switch, the neural network control calculates the outlet temperature based on the input signals from various sensors. In addition, corrections in accordance with the signals from the evaporator temperature sensor (No. 1 cooler thermistor) and the engine coolant temperature sensor are added to control the outlet air temperature. -
      Left and Right Independent Control The temperature setting for the driver and front passenger is controlled independently in order to provide a separate vehicle interior temperature for the right and left sides of the vehicle. Thus, air conditioning control that accommodates different occupant preferences has been realized. -
      3-zone Control*1 The temperature setting for the driver, front passenger and rear passengers is controlled independently in order to provide 3 vehicle interior temperature zones, one each for the driver, front passenger and rear passengers. Thus, air conditioning control that accommodates different occupant preferences has been realized. -
      Blower Control Controls the blower motor with fan sub-assembly in accordance with the airflow volume that has been calculated by the neural network control based on the input signals from various sensors. -
      Blower Customization Control*2 During automatic air conditioning operation, the air volume can be adjusted in 3 levels using the air conditioning control assembly (FAST/ECO switch): NORMAL → ECO (small air volume) → FAST (large air volume). -
      Air Outlet Control Automatically switches the outlets in accordance with the outlet mode ratio that has been calculated by the neural network control based on the input signals from various sensors. -
      Air Inlet Control Automatically controls the air inlet control damper in accordance with the airflow volume that has been calculated by neural network control. -
      Refrigerant Volume Detection Control Judges a shortage of refrigerant volume based on signals from each sensor and informs the user by turning off the indicator light of the A/C switch.
      Variable Capacity Compressor Control Controls the compressor with pulley assembly, by turning it on or off, and the discharge capacity based on the signals from various sensors.
      Parking Fresh Control By automatically switching to fresh air mode when the vehicle is parked. Ventilation of the parked vehicle is facilitated and outside air is introduced into the air conditioner unit assembly.
      ECO Drive Mode Control*3 When set to ECO drive mode, the air conditioning amplifier assembly decreases the blower speed. -

      ○: Equipped

      -: Not equipped

      *1: Models with 3-zone control

      *2: Models with FAST/ECO switch

      *3: Models with drive mode select switch

    2. Neural Network Control


      1. In the previous automatic air conditioning system, the air conditioning amplifier assembly determined the required outlet air temperature and blower air volume in accordance with a calculation formula that had been obtained based on information received from the sensors. However, because the senses of a person are rather complex, a given temperature is sensed differently depending on the environment in which the person is situated. For example, a given amount of solar radiation can feel comfortably warm in a cold climate, but extremely uncomfortable in a hot climate. Therefore, as a technique for performing a high level of control, a neural network is used in the automatic air conditioning system. With this technique, the data that has been collected under varying environmental conditions is stored in the air conditioning amplifier assembly, which effects control to provide enhanced air conditioning comfort.

      2. The neural network control consists of neurons in an input layer, an intermediate layer, and an output layer. The input layer neurons process the input data of the ambient temperature, the amount of sunlight and the room temperature based on the signals of the switches and sensors, and output them to the intermediate layer neurons. Based on this data, the intermediate layer neurons adjust the strength of the links among the neurons. The sum of this data is then calculated by the output layer neurons in the form of the required outlet temperature, solar correction, target airflow volume and outlet mode control volume. Accordingly, the air conditioning amplifier assembly controls the servo motors and blower motor with fan sub-assembly in accordance with the control volumes that have been calculated by neural network control.

        B00831XE01
    3. ECO Drive Mode Control


      1. During ECO drive mode, the air conditioning amplifier assembly restricts air conditioning system performance under specified conditions, thus improving fuel economy.

      2. The ECO drive mode control is activated when the ECO switch (electric parking brake switch assembly) is operated, and then restricts air conditioning system performance as described below:

        Control Outline
        Inside/Outside Air Switch Control Automatically switches the air inlet port to the internal air circulation mode when the outside air temperature is equal to or higher than a predetermined temperature, reducing the power consumption.
        Blower Level Control Sets the blower level in AUTO mode lower than normal, and suppresses the power consumption.
    4. Refrigerant Volume Detection Control


      1. The air conditioning amplifier assembly judges the volume of refrigerant from the ambient temperature, refrigerant pressure and the temperature of the cool air just past the No. 1 cooler evaporator sub-assembly. When the air conditioning amplifier assembly judges that there is a refrigerant shortage, it turns off the indicator light of the A/C switch. At that time, the compressor with pulley assembly stops operating.

    5. Parking Fresh Control


      1. While parking, fresh air introduction mode is automatically selected to enhance ventilation and reduce any odor remaining in the air conditioning unit, thus odor during engine start-up is minimized.

        B0082XSE12
  3. DIAGNOSIS


    1. The air conditioning amplifier assembly has a self-diagnosis function. It stores any operation malfunctions in the air conditioning system or heater system in memory in the form of Diagnostic Trouble Codes (DTCs). For details, refer to the Repair Manual.