System Description

The air conditioning system has the following controls:

1. Mode Position and Damper Operation
   Fig 1: Mode Position And Damper Operation Diagram

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002© TOYOTA, LICENSE AGREEMENT TMS1002© TOYOTA, LICENSE AGREEMENT TMS1002© TOYOTA, LICENSE AGREEMENT TMS1002© TOYOTA, LICENSE AGREEMENT TMS1002© TOYOTA, LICENSE AGREEMENT TMS1002
   FUNCTIONS OF MAIN DAMPERS:
   
   

   Control Damper	Operation Position	Damper Position	Operation
   Air Inlet Control Damper	FRESH	A	Brings in fresh air.
   	RECIRC	B	Recirculates internal air.
   Air Mix Control Damper	MAX COLD to MAX HOT Temperature Setting 16°C (61°F) to 30°C (86°F)	C - D - E	Varies the mixture ratio of the fresh air and the recirculation air in order to regulate the temperature continuously from HOT to COLD.
   Mode Control Damper	DEF Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	H, K	Defrosts the windshield through the front defroster and side register.
   	FOOT / DEF Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	H, J	Defrosts the windshield through the front defroster and side register, while air is also blown out from the front and rear footwell register ducts.
   	FOOT Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	H, I	Air blows out of the footwell register duct, rear footwell duct, and side register. In addition, air blows out slightly from the front defroster.
   	BI-LEVEL Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	F, I	Air blows out of the center register, side register, and front and rear footwell register ducts.
   	FACE Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	F, K	Air blows out of the center register, and side register.

1. Air Outlets and Airflow Volume
   Fig 2: Identifying Air Outlets And Airflow Volume

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   INDICATION (MODE)	CTR	SIDE	FOOTWELL	DEFROSTER
   	A	B	C	D
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002 FACE	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002 BI-LEVEL	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002 FOOT	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002 FOOT/DEF	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002 DEF	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   The size of the circle ◦ indicates the proportion of airflow volume.

1. General
   1. An A/C compressor is a continuously variable capacity type in which its capacity varies in accordance with the cooling load of the air conditioner.
   2. This compressor consists of the shaft, lug plate, piston, shoe, crank chamber, cylinder, and solenoid control valve.
   3. The solenoid control valve that adjusts the suction pressure so that the suction pressure can be controlled as desired is provided.
   4. The plastic DL (Damper Limiter) type A/C pulley is used.
      Fig 3: Exploded View Of A/C Compressor

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2. Operation
   1. The crank chamber is connected to the suction passage. A solenoid control valve is provided between the suction passage (low pressure) and the discharge passage (high pressure).
   2. The solenoid control valve operates under duty cycle control in accordance with the signals from the air conditioning amplifier.
      Fig 4: A/C Compressor Operation Diagram

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   3. When the solenoid control valve closes (solenoid coil is energized), a difference in pressure is created and the pressure in the crank chamber decreases. Then, the pressure that is applied to the right side of the piston becomes greater than the pressure that is applied to the left side of the piston. This compresses the spring and tilts the lug plate. As a result, the piston stroke increases and the discharge capacity increases.
      Fig 5: A/C Compressor Operation Diagram (solenoid Coil Is Energized)

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   4. When the solenoid control valve opens (solenoid coil is not energized), the difference in pressure disappears. Then, the pressure that is applied to the left side of the piston becomes the same as the pressure that is applied to the right side of the piston. Thus, the spring elongates and eliminates the tilt of the lug plate. As a result, there is small piston stroke and the discharge capacity decreases.
      Fig 6: A/C Compressor Operation Diagram (Solenoid Coil Is Not Energized)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

The ambient temperature sensor detects the outside temperature based on changes in the resistance of its built-in thermistor and sends a signal to the A/C amplifier.

The evaporator temperature sensor detects the temperature of the cool air immediately past the evaporator in the form of resistance changes, and outputs it to the A/C amplifier.

The A/C pressure sensor detects the refrigerant pressure and outputs it to the A/C amplifier in the form of voltage changes.