System Description

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Manual Air Conditioning System): SYSTEM DESCRIPTION

1. GENERAL

(a) The air conditioning system has the following controls.





* *: without DEF, FOOT/DEF mode

2. MODE POSITION AND DAMPER OPERATION





Function of Main Damper





3. AIR OUTLETS AND AIRFLOW VOLUME









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

4. A/C LOCK SENSOR

The A/C lock sensor sends A/C pulley speed signals to the air conditioning amplifier assembly. The air conditioning amplifier assembly determines whether the A/C compressor is locked or not by using those signals and engine speed signals.

5. No. 1 COOLER THERMISTOR

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

6. BLOWER WITH FAN MOTOR SUB-ASSEMBLY

The blower with fan motor sub-assembly has a built-in blower controller, and is controlled by the air conditioning amplifier assembly using duty control.

7. AIR CONDITIONING HARNESS ASSEMBLY (BUS CONNECTOR)

(a) A BUS connector is used in the wire harness that connects the servo motor to the air conditioning amplifier assembly.









(b) 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.





8. SERVO MOTOR

(a) 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.





9. QUICK HEATER ASSEMBLY (w/ PTC Heater)

(a) General

(1) The PTC heater is located above the heater core in the air conditioner unit.

(2) 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.





(b) PTC Heater Operating Conditions

(1) 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.





10. COOLER THERMISTOR (AMBIENT TEMPERATURE SENSOR)

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