A/C System Description - Components

Outside Air Temperature Sensor 

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.

Courtesy of HONDA, U.S.A., INC.

A/C Condenser 

Sub Cool Cycle Condenser System 

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 high 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 high 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.

Courtesy of HONDA, U.S.A., INC.

Electric A/C Compressor 

The electric A/C compressor is pump driven by a built-in motor to compress the A/C refrigerant. The compressed refrigerant from the electric A/C compressor turns into high temperature and high pressure gas that is sent to a condenser. The electric A/C compressor has a mechanical relief valve, and the valve opens when pressure exceeds the rated value. It cannot be reused, and should be replaced. When the high voltage battery's state of charge is significantly low (below level "L" as shown on state of charge (SOC) analog meter at the gauge control module), operation of the electric A/C compressor will be limited and/or stop in order to divert the remaining electricity to vehicle propulsion.

NOTE:  This illustration is an example only. The appearance and structure of the actual parts may vary depending on the model.

Courtesy of HONDA, U.S.A., INC.

A/C Pressure Sensor 

The A/C pressure 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 electric A/C compressor. When the A/C system pressure rises to the upper limit, or decreases to the lower limit, the PCM stops the electric A/C compressor to protect the system.

• Upper limit: 2, 950 kPa (30.08 kgf/cm 2, 427.9 psi)
• Lower limit: 196 kPa (2.00 kgf/cm 2, 28.4 psi)

NOTE:  This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model.

Courtesy of HONDA, U.S.A., INC.

Electric Heater Coolant Pump 

The electric heater coolant pump circulates the engine coolant through the heater core. The climate control unit drives the electric heater coolant pump based on the setting temperature and information that is received from each sensor.

Courtesy of HONDA, U.S.A., INC.

Sunlight Sensor 

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.

Courtesy of HONDA, U.S.A., INC.

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 electric A/C compressor and fans are cycled off briefly if the temperature approaches the freezing point of water. If the evaporator temperature gets 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.

Courtesy of HONDA, U.S.A., INC.

Humidity/In-Car Temperature Sensor 

The humidity/in-car temperature sensor has a humidity sensor and an in-car temperature sensor. The climate control unit receives humidity information from the sensor to help control the electric A/C compressor operation. When it is humid, the climate control unit operates the electric A/C compressor to prevent a windshield from being fogged. When the humidity is low enough, the climate control unit reduces the operating time for the electric A/C compressor. A flexible hose connects the sensor case to an aspirator on the HVAC unit to detect the accuracy of temperature and humidity.

NOTE:  This illustration is an example only. Appearance and structure of the actual parts may vary depending on the model.

Courtesy of HONDA, U.S.A., INC.

PTC Heater 

When the engine coolant temperature is low, the heating performance is not available due to low engine coolant temperature. The climate control unit turns on the electric heater in the PTC heater core and secures heating performance. The climate control unit drives PTC heater relays and turns on the electric heater and secures heater performance. If heater core temperature rises enough, the climate control unit turns off the PTC heater relay and the power supply to the PTC heater.

PTC: Positive Temperature Coefficient

NOTE:  This illustration is an example only. Appearance, structure of the actual parts and a portion of usable PTC heater circuit may vary depending on the model.

Courtesy of HONDA, U.S.A., INC.