Toyota CH-R Service Manual: System Description

SYSTEM DESCRIPTION

GENERAL

The air conditioning system has the following controls.

NEURAL NETWORK CONTROL

MODE POSITION AND DAMPER OPERATION

Mode Position and Damper Operation

Control Damper	Operation Position	Damper Position	Operation
Air Inlet Control Damper	FRESH	A1	Allows fresh air to enter.
	RECIRCULATION	A2	Causes internal air to recirculate.
Air Mix Control Damper	HI - LO	B1 - B2	Varies the driver side mixture ratio of cool air and hot air in order to regulate the temperature continuously from HI to LO.
		C2 - C1	Varies the front passenger side mixture ratio of cool air and hot air in order to regulate the temperature continuously from HI to LO.
Air Outlet Control Damper	DEF	E, G, J	Defrosts the windshield through the center defroster, side defrosters and side registers.
	FOOT/DEF	E, G, I to J	Defrosts the windshield through the center defroster, side defrosters and side registers, while air is also blown out from the front footwell register ducts.
	FOOT	D, (D to E), G, I	Air blows out of the front footwell register ducts and side registers. In addition, air blows out slightly from the center defroster and side defrosters.
	B/L	D, F to H, I to J	Air blows out of the center registers, side registers and front footwell register ducts.
	FACE	D, F, J	Air blows out of the center registers and side registers.

AIR OUTLETS AND AIRFLOW VOLUME

The size of each circle ○ indicates the ratio of airflow volume.

(a) Air Outlets and Airflow Volume.

Mode	FACE		FOOT		DEF
	Center	Side	Front	Rear*1	Center	Side
	A	B	C	D	E	F
FACE
B/L
FOOT
FOOT/DEF
DEF

FRESH AIR INTRODUCTION WHILE PARKING CONTROL

When 60 seconds have elapsed since the ignition switch has been turned off, the air conditioning amplifier assembly uses control logic which automatically changes the air inlet to FRESH mode to purge undesired odors from the air conditioning unit.

This logic will therefore reduce undesired odors upon starting the air conditioning system.

COMPRESSOR

(a) General:

(1) The compressor is a continuously variable capacity type in which its capacity can be varied in accordance with the cooling load of the air conditioning system.

(b) Solenoid Valve Operation:

(1) The crank chamber is connected to the suction passage. A solenoid valve is provided between the suction passage (low pressure) and the discharge passage (high pressure).

(2) The solenoid valve operates under duty cycle control in accordance with the signals from the air conditioning amplifier assembly.

(3) When the solenoid 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 swash plate. As a result, the piston stroke increases and the discharge capacity also increases.

(4) When the solenoid 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 swash plate. As a result, there is no piston stroke, and the discharge capacity is reduced.

(c) CS Valve Operation:

(1) The CS valve consists of passage A and passage B. If the vehicle is left parked for a long period, refrigerant may accumulate in the crank chamber due to the heat capacity difference.

(2) The solenoid control valve is controlled by the air conditioning amplifier assembly. While the compressor is operating, the solenoid control valve pushes down the CS valve rod and opens passage A.

(3) Under the above condition, only if the refrigerant accumulates in the crank chamber, the crank chamber pressure will become high. As a result, the bellows will contract because of the pressure difference with its internal pressure (vacuum), and opens passage B.

(4) This causes the accumulated refrigerant to be drawn in via passage A and passage B, clearing the accumulated refrigerant earlier and ensuring a more immediate cooling effect.

ION GENERATOR SUB-ASSEMBLY (w/ Ion Generator)

(a) The ion generator sub-assembly operates when the blower switch are on.

(b) The ion generator sub-assembly emits "nanoe" ions that are electrically charged and encapsulated with water. The ions are discharged into the cabin through the side register (front passenger side) to provide skin-friendly clean air.*

CAUTION:

Do not attempt to disassemble or repair the ion generator sub-assembly because it contains high voltage parts.

NOTICE:

Do not insert anything into the side register (front passenger side), attach anything to it, or use sprays around it. Doing so may cause the ion generator sub-assembly to not work properly.

HINT:

"nanoe" is a trademark of Panasonic Co., Ltd.

NO. 1 COOLER THERMISTOR (EVAPORATOR TEMPERATURE SENSOR)

The No. 1 cooler thermistor (evaporator temperature sensor) detects the temperature of the cool air immediately after the evaporator in the form of resistance changes, and outputs it to the air conditioning amplifier assembly.

BLOWER MOTOR WITH FAN SUB-ASSEMBLY

The blower motor is controlled using duty control performed via the blower resistor from the air conditioning amplifier assembly.

BLOWER RESISTOR

The blower resistor controls the blower motor with fan sub-assembly based on changes in the signal sent by the air conditioning amplifier assembly.

SERVO MOTOR

Servo motor, uses a step motor type. The motor inside of four coils have always added the battery voltage. An air conditioning amplifier assembly is as many times as necessary until the position of the target, move the voltage of each of the coil to the position of the target repeat the ON and OFF in order.

QUICK HEATER ASSEMBLY (w/ PTC Heater)

(a) General

(1) The quick heater assembly is located above the heater core in the air conditioning radiator assembly.

(2) The quick heater assembly 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.

(b) Quick Heater Assembly Operating Conditions

(1) The quick heater assembly is turned on and off by the air conditioning amplifier assembly in accordance with the engine coolant temperature, ambient temperature, temperature setting, and electrical load (generator power ratio).

COOLER THERMISTOR (ROOM TEMPERATURE SENSOR)

The cooler thermistor (room temperature sensor) detects the cabin temperature based on changes in the resistance of its built-in thermistor and sends a signal to the air conditioning amplifier assembly.

THERMISTOR ASSEMBLY

The thermistor assembly detects the outside temperature based on changes in the resistance of its built-in thermistor and sends a signal to the combination meter assembly and via CAN communication, it sends the outside temperature information to air conditioning amplifier assembly.

AUTOMATIC LIGHT CONTROL SENSOR

The automatic light control 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 and outputs these sunlight strength signals to the air conditioning amplifier assembly.

AIR CONDITIONER PRESSURE SENSOR

The air conditioner pressure sensor detects the refrigerant pressure and outputs it to the air conditioning amplifier assembly in the form of voltage changes.