AIR CONDITIONING SYSTEM

The air conditioning system uses the following controls:

Control	Outline
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 that of a human brain.
Automatic Recirculation Control	Automatically changes the air inlet mode to fresh air or recirculate mode in accordance with the level of harmful elements in the outside air, cabin temperature and outside temperature.
Automatic Recirculation Control	Changes the sensitivity of the smog ventilation sensor.
Pollen Removal Mode Control	Activated by the pollen removal mode switch operation, switches the air outlet to the FACE mode and sends air which has passed through the clean air filter to the area around the upper part of the bodies of the driver and front passenger. This air is filtered by the clean air filter in order to remove pollen.
Outlet Air Temperature Control	Based on the temperature set at the temperature control switch, the neural network control calculates the outlet air temperature based on the input signals from various sensors.
Outlet Air Temperature Control	The temperature settings for the driver and front passenger are controlled independently in order to provide a separate vehicle interior temperature for the right and left sides of the vehicle. As a result, air conditioning control that accommodates occupant preferences has been achieved.
Blower Control	Controls the blower motor in accordance with the airflow volume that has been calculated by the neural network control based on the input signals from various sensors.
Blower Control	Automatically increases the blower level when the defroster is on.
Air Outlet Control	Automatically switches the air outlets in accordance with the outlet mode 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 the neural network control.
Air Inlet Control	Automatically switches between fresh air mode and recirculation mode in conjunction with the set temperature while the automatic air conditioning is operating.
Cooler Compressor Control	Controls the blower motor in accordance with the airflow volume that has been calculated by the neural network control based on the input signals from various sensors.
Memory Call Control	Memorizes the last front and rear air conditioning settings when the engine switch is turned from on (IG) to off in accordance with the ID code of the key that is used to operate the vehicle. The memory call control then recalls the settings if the key is used when the engine switch is turned on (IG). This function operates when both of the following conditions are met: The inside of the outside door handle is touched or the driver door is unlocked using the unlock button, and then the driver door is opened. Engine switch is turned on (IG).
Heated Windshield Defroster Control	The heated windshield defroster system is activated when the engine switch is turned on (IG) and the deicer and defroster switch is pushed. The air conditioning amplifier assembly performs timer control of the heated windshield defroster system in accordance with the ambient temperature as follows. Tech Tips The maximum possible operation time is used for timer control. (Example: when the ambient temperature is -19°C, the operation time will be 840 seconds.)
Rear Window Defogger Control	Switches the rear defogger and outer rear view mirror heaters on for 15 minutes when the rear defogger button is pressed. Switches them off if the button is pressed while they are operating.
Self-diagnosis	Checks the sensors in accordance with the operation of the air conditioning switches, and then displays a Diagnosis Trouble Code (DTC) on the clock to indicate if there is a malfunction or not (sensor check function).
Customization	Some functions can be customized. For details, refer to the Repair Manual.

Neural Network Control

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 the calculation formula that had been obtained based on information received from the sensors. However, because the sensors 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 effecting 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.
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 outputs 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 with fan motor sub-assembly in accordance with the control volumes that have been calculated by the neural network control.

Automatic Recirculation Control

When the automatic recirculation control is operating, the air conditioning amplifier assembly automatically changes air inlet mode to fresh air or recirculate air mode based on signals from the smog ventilation sensor, outside temperature and room temperature sensors when AUTO air inlet mode is selected.
- The air conditioning amplifier assembly detects harmful elements (CO, HC and NOx) based on smog ventilation sensor signals and automatically switches air inlet mode to recirculate air mode to prevent such harmful elements from entering the cabin.
- The air conditioning amplifier assembly detects the room temperature based on signals from the room temperature sensor and automatically switches air inlet mode to recirculate air mode to cool the room quickly.
- The air conditioning amplifier assembly detects outside temperature based on an ambient temperature sensor signal and automatically switches air inlet mode to fresh air mode to prevent the windshield from fogging up.
Tech Tips

The smog ventilation sensor cannot detect elements such as smoke from a bonfire or factory exhaust, foul or animal odors, and dirt or dust particles. Therefore, air inlet mode is not switched in accordance with those elements. Depending on the direction of the wind, the smog ventilation sensor might not be able to detect the undesirable elements (CO, HC and NOx), allowing them to enter the cabin.

Memory Call Control

The air conditioning amplifier assembly stores the front and rear air conditioning settings for each memory number when the engine switch is turned off.
The main body ECU converts the key ID code into a memory number, stores it and sends the converted signal to the air conditioning amplifier assembly.
The air conditioning amplifier assembly stores the memory number and air conditioning settings.
When the doors are unlocked, the certification ECU recognizes the key ID code and sends it to the main body ECU.
Upon receiving the key ID code signal, the main body ECU converts the signal into a memory number signal and sends it to the air conditioning amplifier assembly.
The air conditioning amplifier assembly then recalls the stored air conditioning settings based on the memory number signal when the engine switch is turned on (IG).

The following air conditioning system settings can be memorized:

Setting		Condition
Air Conditioning Switch		On or Off
AUTO Switch		On or Off
Temperature Setting	Driver	LO, 16°C to 32°C (65°F to 85°F) or HI
Temperature Setting	Front Passenger	LO, 16°C to 32°C (65°F to 85°F) or HI
Blower Fan Speed		Level 1 to 7
Air Inlet Mode		Fresh or Recirculate
Air Outlet Mode		Face, Bi-Level, Foot, Foot and Defroster or Defroster
Dual Switch		On or Off

The following rear air conditioning system settings can be memorized:

Setting	Condition
Air Conditioning Switch	On or Off
AUTO Switch	On or Off
Temperature Setting	LO, 16°C to 32°C (65°F to 85°F) or HI
Blower Fan Speed	Level 1 to 7

Tech Tips

Memory call control of the air conditioning system can be canceled or re-enabled using an intelligent tester II.
The main body ECU can store a maximum of 3 memory numbers.
The memory call function recalls the key ID that was recognized when the door was unlocked. This happens even when the user brings 2 keys or more, or the user uses different keys to unlock the door and turn the engine switch on (IG).
Using the intelligent tester II, the main body ECU can be made to convert the ID numbers of different key to a desired memory number. Therefore, all key IDs can be converted to an identical memory number, or 2 memory numbers can be divided among 3 keys.
For details of key ID code registration, refer to the Repair Manual.

Pollen Removal Mode Control

When the pollen removal mode switch is pressed, the pollen removal mode control is activated. Then, the air outlet is switched to the FACE mode and recirculated pollen-free air flows in the area around the upper part 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 cooler compressor assembly, recirculation damper servo sub-assembly, mode damper servo sub-assembly and blower with fan motor sub-assembly as shown in the timing chart below.
- This control usually operates for approximately 3 minutes. However, when the ambient temperature is low [5°C (41°F) maximum], it will operate for approximately 1 minute.
- 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.

Quick Heater Control

The on/off function of the quick heater assembly is controlled by the air conditioning amplifier assembly in accordance with the engine coolant temperature, engine speed, air mix setting cooler (ambient temperature sensor) thermistor and electrical load (generator power ratio).
For example, the heating value of the operating quick heater assemblies varies depending on the engine coolant temperature, as shown in the graph below:

Cool Box Control

On models for G.C.C. countries, when the cool box is turned on while the air conditioning system is off and when the air conditioning system is turned off while the cool box is on, the blower motor will be in Lo mode, the outlet will be in DEF mode and the set temperature will be 25°C (77°F). As a result, the cool box can now be turned on whether the air conditioning system is on or off.