AIR CONDITIONING SYSTEM

Quick Heater Control

1. 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, and electrical load (generator power ratio).

2. For example, the heating value of the operating quick heater assemblies varies depending on the engine coolant temperature as shown in the graph below:

   

Air Conditioning Unit

1. The air conditioning unit consists of a No. 1 cooler evaporator sub-assembly, heater radiator unit sub-assembly, servomotors, front No. 1 cooler thermistor, quick heater assembly* and blower with fan motor sub-assembly.

   
   

   • *: Models with quick heater assembly

2. A semi-central location air conditioning unit, in which the No. 1 cooler evaporator sub-assembly and heater radiator unit sub-assembly are placed in the vehicle's longitudinal direction, is used.

   

   Text in Illustration

   *1	No. 1 Cooler Evaporator Sub-assembly	*2	Heater Radiator Unit Sub-assembly
   	Front	-	-

No. 1 Cooler Evaporator Sub-assembly

1. A Revolutionary super-slim Structure (RS) evaporator is used. By placing the tanks at the top and the bottom of the No. 1 cooler evaporator sub-assembly and by using a micropore tube construction, the following effects have been achieved:

   
   

   • Heat exchanging efficiency is ensured.

   • The temperature distribution is made uniform.

   • The No. 1 cooler evaporator sub-assembly has been made thinner.

   

   Text in Illustration

   *1	Tank	*2	Micropore Tube
   *3	Cooling Fin	-	-

Servomotor

1. In contrast to the previous type that detects the position by way of a potentiometer voltage, the pulse pattern type servomotor detects the relative position by way of the 2-bit on/off signals.

2. The forward and reverse revolutions of this motor are detected by way of 2 phases, A and B, which output 4 types of patterns. The air conditioning amplifier assembly counts the number of pulse patterns in order to determine the stopped position.

   

Quick Heater Assembly

1. The quick heater assembly is located above the heater radiator unit sub-assembly in the air conditioning unit.

2. The quick heater assembly consists of a PTC element, an aluminum fin, and a brass plate. When current is applied to the PTC element, it generates heat to warm the air that passes through the unit.

   

   Text in Illustration

   *1	Brass Plate	*2	PTC Element
   *3	Aluminum Fin	-	-

Combustion Type Power Heater Assembly

1. The combustion type power heater assembly consists mainly of a heater exchanger, a glow plug, a motor, an air fan, an ECU, an engine coolant temperature sensor, an overheating prevention sensor, a flame sensor, an intake pipe, an exhaust pipe and a fuel pump.

2. This heater is installed between the engine and heater radiator unit sub-assembly. The engine coolant from the engine flows through the spiral passage around the heat exchanger and flows into the heater radiator unit sub-assembly. At this time, the glow plug ignites the air and fuel in the combustion chamber of the heat exchanger, and the resultant heat of combustion heats the engine coolant.

   

   

Clean Air Filter

1. A pollen removal type clean air filter is used to remove dust, pollen, and other micron particles from air entering from outside the vehicle to provide a comfortable cabin of clean air. The clean air filter is installed in the upper section of the blower fan.

   

   *1

   Clean Air Filter

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Condenser Assembly

1. A sub-cool condenser is used. This is a multi-flow condenser consisting of 3 portions: a condensing portion, a super-cooling portion and a gas-liquid separator (modulator) all integrated together. This condenser assembly uses a sub-cool cycle for its cooling cycle system to improve heat-exchanging efficiency.

2. In the sub-cool cycle, after the refrigerant passes through the condensing portion of the condenser assembly, both the liquid refrigerant and the gaseous refrigerant that could not be liquefied are cooled again in the super-cooling portion. Thus, the refrigerant is sent to the No. 1 cooler evaporator sub-assembly in an almost completely liquefied state.

   

   Text in Illustration

   *1	Condensing Portion	*2	Modulator
   *3	Desiccant	*4	Filter
   *5	Super-cooling Portion	-	-
   	Gaseous Refrigerant		Liquid Refrigerant

   Tech Tips

   The point at which the air bubbles disappear in the refrigerant of the sub-cool cycle is lower than the proper amount of refrigerant with which the system must be filled. Therefore, if the system is recharged with refrigerant based on the point at which the air bubbles disappear, the amount of refrigerant would be insufficient. As a result, the cooling performance of the system will be affected. If the system is overcharged with refrigerant, this will also lead to reduced performance. For the proper method of verifying the amount of the refrigerant and to recharge the system with refrigerant, refer to the Repair Manual.

   

   *1	Properly Recharged Amount
   *2	High Pressure
   *3	Point at which Bubbles Disappear
   *4	Amount of Refrigerant

Cooler Compressor Assembly (Except Models with 1GD-FTV Engine or 2TR-FE Engine)

1. A compact, lightweight, and low-noise 10-cylinder swash plate type cooler compressor (10S17C) is used.

   

Cooler Compressor Assembly (Models with 2TR-FE Engine or 1GD-FTV Engine)

1. A fixed capacity swash plate type 10SRE18C compressor is used.

2. A rotary valve that intakes refrigerant directly into the cylinder is used, achieving a reduction in refrigerant intake loss.

3. A shaft oil separator that separates compressor oil from the refrigerant is used.

   
   

   • Compressor oil, which has been mixed with the refrigerant and circulated in the air conditioning cycle, is separated by the shaft oil separator built into the shaft and accumulated in the compressor.

   • For the shaft oil separator, an oil return passage is located between the cylinder and the lug plate, and refrigerant gas in which a small amount of oil is mixed is sent to the intake chamber. As a result, the oil circulation amount in the air conditioning cycle is reduced.

   

   Text in Illustration

   *1	Piston	*2	Rotary Valve
   *3	Shaft	*4	Oil Separator
   *5	Swash Plate	-	-
   *a	The illustrations shown are example only.	-	-

4. Rotary Valve

   
   

   • The rotary valve has a structure where refrigerant passing through the center of the hollow shaft is taken into the compression areas within the cylinder. The intake of refrigerant occurs when the openings of the shaft and cylinder overlap.

   

   Text in Illustration

   *1	Cylinder	*2	Piston
   *3	Shaft	-	-
   *a	Rotary Valve Intake	*b	Position where Rotary Valve Intake and Cylinder Intake Passage Align
   *c	Cylinder Intake Passage	*d	Flow of Refrigerant

Cool Box

1. The cool box consists primarily of a cool box amplifier, an evaporator (for cool box), a cool box blower motor, a cool box switch, and an expansion valve. The connected refrigerant circuit of the front air conditioning cools the cool box.

   

   Text in Illustration

   *1	Condenser Assembly	*2	Cooler Compressor Assembly
   *3	Check Valve	*4	No. 1 Cooler Evaporator Sub-assembly
   *5	No. 1 Cooler Evaporator Sub-assembly No.2	*6	Cool Box
   *7	Magnetic Valve	*8	Cooler Expansion Valve

Front Air Conditioning Mode Position and Damper Operation

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 Temp. Setting		E - D - C (E' - D' - C')		Varies the mixture ratio of the cold air and the hot air in order to regulate the temperature continuously from HOT to COLD.
Max Cool Damper	Max Cool		V		Open in the MAX COOL position
	Except Max Cool		W		Closed 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		DEF	H, I, S, U, X		Defrosts the windshield through the center defroster, and side defroster.
		FOOT/DEF	Max Hot Position	H, K, R, T, W, Y	Defrosts the windshield through the center defroster, side defroster, front and rear footwell register ducts while air is also blown out from the front and rear center registers and side register.
			Except Max Hot Position	H, M, Q, T, X
		FOOT	Max Hot Position	H, M, P, T, W, Y	Air blows out of the front and rear footwell register duct. In addition, air blows out slightly from the center register, side register, rear center register*, center defroster and side defroster.
			Except Max Hot Position	H, M, O, T, X
		BI-LEVEL	Max Hot Position	G, L, N, W, Y	Air blows out of the front and rear center registers*, side register, and front and rear footwell register ducts.
			Except Max Hot Position	G, L, N, T, X
		FACE	Auto Mode	F, J, N, T, X	Air blows out of the front and rear center registers*, and side register.
			Manual Mode	F, I, N, T, X

• *: Models with single air conditioning

Rear Air Conditioning Mode Position and Damper Operation

Control Damper	Operation Position		Damper Position	Operation
Mode Control Door		FACE	A	Air blows out of the rear roof side register.
		BI-LEVEL	B	Air blows out of the rear roof side register and the rear footwell register.
		FOOT	C	Air blows out of the rear footwell register.
Air Mix Control Damper	MAX COLD to MAX HOT Temp. Setting		D - E	Varies the mixture ratio of the cold air and the hot air in order to regulate the temperature continuously from HOT to COLD.

Front Air Outlets and Airflow Volume (Models with Automatic Air Conditioning)

Indication	Mode	Section		A	B	C	D	E	F
		Auto	Manual	Center	Side	Front Footwell	Rear Face*1	Rear Footwell	Defroster
	FACE-U	●	●			-		-	-
	FACE-L*2	●	-						-
	BI-LEVEL	●	●						-
	FOOT	●	●
	FOOT/DEF	●	●
	DEF	-	●	-	-	-	-	-

Front Air Outlets and Airflow Volume (Models with Manual Air Conditioning or Manual Heater)

Indication	Mode	A	B	C	D	E	F
		Center	Side	Front Footwell	Rear Face*	Rear Footwell	Defroster
	FACE			-		-	-
	BI-LEVEL						-
	FOOT
	FOOT/DEF
	DEF	-	-	-	-	-

Rear Air Outlets and Airflow Volume

Indication	Mode	A	B
	FACE		-
	BI-LEVEL
	FOOT	-