Air Conditioning System (For Automatic Air Conditioning System) -- System Description |
| GENERAL |
The air conditioning system has the following controls.
Control Outline Neural Network Control This control is capable of performing 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 similar to that of a human brain. Outlet Air Temperature Control Based on the temperature set by the temperature control dial, neural network control calculates outlet air temperature based on input signals from various sensors. Pollen Removal Mode Control - When the pollen removal mode switch is pressed, pollen removal mode control is activated and the air vent is switched to the FACE mode.
- Sends air, which is filtered by the clean air filter to remove pollen, to the area around the upper parts of the bodies of the driver and front passenger.
Left and Right Independent Control The temperature settings for the driver and front passenger are controlled independently in order to provide separate vehicle interior temperatures for the right and left sides of the vehicle. Blower Control Controls the blower motor in accordance with the airflow volume that has been calculated by neural network control based on the input signals from various sensors. Air Outlet Control Automatically switches the air outlets in accordance with the outlet mode that has been calculated by neural network control. In accordance with the engine coolant temperature, ambient air temperature, amount of sunlight, required blower speed, outlet temperature and vehicle speed conditions, this control automatically switches the blower outlet to foot and defroster mode to prevent the windows from becoming fogged up when the ambient air temperature is low. Air Inlet Control Automatically controls the air inlet control damper to help achieve the calculated outlet air temperature that is required. Drives the air inlet control servo motor according to the operation of the air inlet control switch and moves the dampers to the fresh or recirculation position. Compressor Control The air conditioning amplifier assembly compares the A/C pulley speed signals, which are transmitted by the ECM (crankshaft position sensor). When the air conditioning amplifier assembly determines that the A/C pulley is locked, it turns off the magnet clutch assembly. Defroster Control Defroster control logic is used to improve defroster performance. Rear Defogger Control When the ignition switch is ON and the rear defogger switch is pushed, the system is activated to keep the defogger heater on for approx. 15 minutes. However, the operating time of the rear defogger can be extended up to approx. 255 minutes when both of the following requirements are met: - Ambient Temperature: -3°C (26.6°F) or less
- Vehicle Speed: 50 km/h (31.1 mph) or more
Diagnosis A Diagnostic Trouble Code (DTC) is stored in memory when the air conditioning amplifier assembly detects a problem with the air conditioning system. - When the pollen removal mode switch is pressed, pollen removal mode control is activated and the air vent is switched to the FACE mode.
| NEURAL NETWORK CONTROL |
- Neural network control collects data under varying environmental conditions and stores it in the air conditioning amplifier assembly. Neural network control uses this data to enhance air conditioning control.
- Neural network control consists of neurons organized into an input layer, intermediate layer and output layer. The input layer neurons process the input data received from the switches and sensors, which includes the outside temperature, amount of sunlight and room temperature, and outputs this data to the intermediate layer neurons. Based on this data, the intermediate layer neurons adjust the strength of the links among the neurons. The result 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. The air conditioning amplifier assembly then controls the servo motors and blower motor in accordance with the control volumes that have been calculated by neural network control.
| POLLEN REMOVAL MODE CONTROL |
When the pollen removal mode switch is pressed, the pollen removal mode control is activated. Then, the air vent is switched to the FACE mode and recirculated pollen free air flows in the area around the upper parts of the bodies of the driver and front passenger.
When the pollen removal mode switch signal is input to the air conditioning amplifier assembly, the air conditioning amplifier assembly controls the magnet clutch assembly, recirculation damper servo sub-assembly, damper servo sub-assembly (mode damper servo) and blower with fan motor sub-assembly as shown in the timing chart.
This control usually operates for approximately 3 minutes.
After this control stops operating, the air conditioning amplifier assembly automatically returns to the mode it was in just before the pollen removal mode switch was pressed.
| MODE POSITION AND DAMPER OPERATION |
Mode Position and Damper Operation
Front Air Conditioning Unit
Function of Main Damper Control Damper Operation Position Damper Position Operation Air Inlet Control Damper Fresh A Brings in fresh air. Recirculation B Recirculates internal air. Air Mix Control Damper MAX COOL to MAX HOT E - D - C
E' - D' - C'Varies the mixture of cold air and hot air in order to regulate the temperature continuously from hot to cool. MAX COOL Damper MAX COOL V Open in the MAX COOL position. Except MAX COOL W Close in all position except MAX COOL position. MAX HOT Damper MAX HOT Y Open in the MAX HOT position. Except MAX HOT X Closed in all position except MAX HOT position. Mode Control Damper 
FaceF, I, N, T, X (FACE 1)
F, J, N, T, X (FACE 2)Air blows out of the front center registers, side registers and rear face registers. (FACE 1)
Air blows out of the front center registers, side registers and rear face registers. In addition, air blows out slightly from the front and rear footwell register ducts. (FACE 2)
Bi-levelG, L, N, T, X Air blows out of the front center registers, side registers, rear face registers and front and rear footwell register ducts. 
FootH, M, P, T, W, Y (MAX HOT position)
H, M, O, T, X (Except MAX HOT Position)Air blows out of the front and rear footwell register ducts.
In addition, air blows out slightly from the front defroster, side registers, front center registers and rear face registers.
Foot/DefH, K, R, T, W, Y (MAX HOT position)
H, M, Q, T, X (Except MAX HOT Position)Defrosts the windshield through the front defroster and side registers while air is also blown out from the front and rear footwell register ducts.
In addition, air blows out slightly from the front center registers and rear face registers.
DefH, I, S, U, X Defrosts the windshield through the front defrosters. Rear Air Conditioning Unit (w/ Rear Air Conditioning System)
Function of Main Damper Control Damper Operation Position Damper Position Operation Mode Control Damper
FaceA Air blows out from the rear roof registers.
Bi-levelB Air blows out from the rear roof registers and rear side registers.
FootC Air blows out from the rear side registers. Air Mix Control Damper MAX COLD to MAX HOT Temperature Setting D, E Varies the mixture of cold air and hot air in order to regulate the temperature continuously from hot to cold.
| AIR OUTLETS AND AIRFLOW VOLUME |
Air Outlets and Airflow Volume
for Front Registers
Indication
(Mode)Front Center Register Side Register Front Footwell Register Rear Face Register* Rear Footwell Register Front Defroster A B C D E F
Face 1
- 
- -
Face 2
-
Bi-level
-
Foot
Foot/Def
Def- - - - - - *: w/o Rear Air Conditioning System
- HINT:
- The size of the circle indicates the proportion of airflow volume.
- The same system is used for LHD and RHD vehicles.
- *: w/o Rear Air Conditioning System
for Rear Registers (w/ Rear Air Conditioning System)
Indication
(Mode)Rear Roof Register Rear Side Register A B
Face-
Bi-level
Foot- - HINT:
- The size of the circle ○ indicates the ratio of airflow volume.
| A/C LOCK SENSOR |
| No. 1 COOLER THERMISTOR |
| BLOWER WITH FAN MOTOR SUB-ASSEMBLY |
| AIR CONDITIONING HARNESS ASSEMBLY (BUS CONNECTOR) |
A BUS connector is used in the wire harness that connects the servo motor to the air conditioning amplifier assembly.
Connector Type Connected to *1: Bus connector Damper servo sub-assembly LH (driver side air mix damper servo) *2: Bus connector Damper servo sub-assembly LH (mode damper servo) *3: Bus connector Damper servo sub-assembly RH (front passenger side air mix damper servo) *4: Bus connector Recirculation damper servo sub-assembly *5: Connector Air conditioning amplifier assembly *6: Connector No. 1 cooler thermistor *7: Bus connector Damper servo sub-assembly RH (driver side air mix damper servo) *8: Bus connector Damper servo sub-assembly LH (front passenger side air mix damper servo) Each BUS connector has a built-in communication/driver IC which communicates with each servo motor connector, actuates the servo motor, and has a position detection function.
| SERVO MOTOR |
The pulse pattern type servo motor detects the relative position using 2-bit on/off signals.
The forward and reverse revolutions of this motor are detected using two signals, A and B, which output four types of patterns. The air conditioning amplifier assembly counts the number of pulse patterns in order to determine the stopped position.
| QUICK HEATER ASSEMBLY (w/ PTC Heater) |
General
The PTC heater is located above the heater core in the air conditioner unit.
The PTC heater consists of a PTC element, aluminum fins and brass plates. When current is applied to the PTC element, it generates heat to warm the air that passes through the unit.
PTC Heater Operating Conditions
The on/off operation of the PTC heater is controlled by the air conditioning amplifier assembly in accordance with the engine coolant temperature, ambient temperature, engine speed, air mix setting and electrical load (generator power ratio).
For example, the number of operating PTC heaters varies according to engine coolant temperature as shown in the graph below.
| VISCOUS WITH MAGNET CLUTCH HEATER ASSEMBLY (w/ Viscous Heater) |
The viscous with magnet clutch heater assembly, which is located on top of the engine, is driven by a drive belt. Pressing the heater switch assembly provided in the instrument panel engages the magnetic clutch, causing the rotor in the viscous with magnet clutch heater assembly to rotate and the silicon oil to mix. The shear heat that is thus generated heats the coolant.
The viscous with magnet clutch heater assembly is controlled in accordance with the engine speed, coolant temperature and ambient temperature. While the power heater is engaged, the engine idling speed is raised to a predetermined value whenever the shift lever is in N or D.
| COOLER THERMISTOR (ROOM TEMPERATURE SENSOR) |
| COOLER THERMISTOR (AMBIENT TEMPERATURE SENSOR) |
| AUTOMATIC LIGHT CONTROL SENSOR (SOLAR SENSOR) |
The automatic light control sensor (solar sensor) consists of a photo diode, 2 amplifier circuits for the solar sensor and a frequency converter circuit for the light control sensor.
The automatic light control sensor (solar sensor) detects (in the form of changes in the current that flows through the built-in photo diode) the changes in the amount of sunlight from the LH and RH sides (2 directions) and outputs these sunlight intensity signals to the air conditioning amplifier assembly.
