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A/C System Description - Components
Outside Air Temperature Sensor
The outside air temperature sensor is installed on the front side of the vehicle, behind the front bumper. The outside air temperature sensor uses a sensor that decreases resistance when temperature rises. The climate control unit calculates the outside air temperature based on the information received from the outside air temperature sensor. NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model. A/C Condenser
The condenser and receiver/dryer are integrated. The main A/C condenser changes the high pressure and temperature refrigerant vapor from the electric A/C compressor into a high pressure and temperature liquid. This allows the refrigerant to release heat to the outside air. The receiver/dryer acts as a reservoir of liquid refrigerant for the expansion valve. It also removes debris and moisture from the refrigerant. The sub A/C condenser cools the high pressure and temperature liquid refrigerant even further to improve A/C performance. NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model. Sub Cool Cycle Condenser System
A/C Pressure Sensor
The A/C pressure sensor is attached to the receiver line on the outlet side of the A/C condenser. The sensor's output voltage changes in response to changes in A/C discharge pressure. The PCM receives the voltage signal and is used to drive the A/C compressor. The PCM also controls the radiator fan and A/C condenser fan. When the A/C system pressure rises to the upper limit, or decreases to the lower limit, the PCM stops the A/C compressor to protect the system.
NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model. A/C Compressor
The A/C compressor is a pump that compresses refrigerant. It is driven by the engine accessory drive belt. When the compressor clutch is OFF, the pulley and armature plate are disconnected and the A/C compressor does not operate. When the compressor clutch is ON, the field coil is energized, creating a strong magnetic field. This magnetic field locks the pulley and armature plate together, driving the compressor. The compressed refrigerant becomes a high pressure and temperature vapor that is sent to the A/C condenser. The A/C compressor has a mechanical relief valve, and the valve opens when refrigerant pressure exceeds the rated value. It cannot be reused, and should be replaced. Variable Capacity Control (1.5 L Engine)
The climate control unit operates the variable capacity control solenoid on the A/C compressor. The solenoid controls the cooling capacity by adjusting the flow of refrigerant pumped through the A/C system. The climate control unit determines the solenoid circuit's current flow based on the outside air temperature sensor, the in-car temperature sensor, and solar radiation values. NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model. Sunlight Sensor
The sunlight sensor is attached to the upper face of the dashboard. The sunlight sensor uses a photodiode-type optical sensor which changes current in proportion to the sunlight intensity. The climate control unit reads the information of the sunlight sensor. NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model. Evaporator Temperature Sensor
The evaporator temperature sensor is a clip-type thermistor, with a sensing element that is directly mounted to the evaporator core fins. The sensor is connected to the climate control unit and constantly monitors the evaporator temperature. The A/C compressor and fans are cycled off briefly if the temperature approaches the freezing point of water. If the evaporator temperature goes too low, the moisture condensing on its cold surfaces will freeze, causing restricted evaporator airflow and poor A/C performance. NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model. In-Car Temperature Sensor
The in-car temperature sensor is attached to the center face of the dashboard and reads in-car temperature. The sensor uses a chip type thermistor-type temperature sensor that decreases resistance when temperature rises and increases resistance when temperature is drops. The climate control unit reads the resistance fluctuation in response to changes in in-car temperature and control the A/C. NOTE: This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model. |
