Climate Control System Description
Climate Control System Description
The air conditioning (A/C) system removes heat from the passenger compartment by transferring heat from the ambient air to the evaporator. The A/C system refrigerant expands in the evaporator, and the evaporator becomes very cold and absorbs the heat from the ambient air. The blower fan pushes air across the evaporator where the heat is absorbed, and then it blows the cool air into the passenger compartment.
This vehicle uses HFC-134a (R-134a) refrigerant, which does not contain chlorofluorocarbons. Pay attention to the following service items:
- Use only the recommended polyalkyleneglycol (PAG) refrigerant oil (DENSO ND-OIL 8) designed for the R-134a A/C compressor. Intermixing the recommended (PAG) refrigerant oil with any other refrigerant oil will result in A/C compressor failure.
- All A/C system parts (A/C compressor, discharge line, suction line, evaporator, A/C condenser, receiver/dryer, expansion valve, O-rings for joints) are designed for refrigerant R-134a.
- Use a halogen gas leak detector designed for refrigerant R-134a.
- Use only a recovery/recycling/charging station that is U.L.-listed and is certified to meet the requirements of SAE J2788 to service the R-134a air conditioning systems.
- Always recover refrigerant R-134a with an approved recovery/recycling/charging station before disconnecting any A/C fitting.
Humidity/In-Car Temperature Sensor
The humidity sensor consists of two sensors. One sensor is for humidity detection, and the other is for in-car temperature detection. When the climate control unit receives signals about the in-car condition from the humidity sensor, and judges that the humidity in the vehicle is very low, the climate control unit reduces the A/C compressor runtime. Engine power loss is kept to a minimum, and fuel economy is increased.
Humidity/In-Car Temperature Sensor Quality
The capacitance of the humidity sensor changes by the adsorption and the evaporation of moisture. The resistance change of the humidity sensor changes the output voltage.
A/C Pressure Sensor
The A/C pressure sensor converts A/C pressure into electrical signals to the PCM.
The response of the A/C pressure sensor is shown in the graph.
NOTE: When the refrigerant is below 196 kPa (2.00 kgf/cm2, 28.4 psi) or above 3,138 kPa (32.00 kgf/cm2, 455.1 psi), the PCM turns the A/C compressor clutch relay off to protect the A/C compressor. When the refrigerant pressure is above 1,670 kPa (17.03 kgf/cm2, 242.2 psi), the PCM switches the radiator and the A/C condenser fans to high speed.
Climate Control Door Positions
Dual Air Mix Control System
i-Dual Zone and i-Tri Zone Climate Control System (With navigation)
The i-Dual zone climate control system automatically controls the temperature and the vent mode of the air direction to the driver's and passenger's side, depending on the angle of the sun, and the direction of the vehicle. It calculates information such as date, time, longitude, and latitude from the navigation system, as well as the radiant strength of the sun from the sunlight sensor, to determine the appropriate mode position and temperature to be directed to each side. The i-Tri zone climate control system is an addition of the automatic controls with the temperature and the vent mode of the air direction to the rear section to the i-Dual zone climate control system.
In the event that the navigation system malfunctions, or when driving in areas where the navigation system cannot determine the vehicle position (non-coverage areas, tunnels, etc.), the climate control system will operate the same as a vehicle without a navigation.
Cool Box
The cool box is located in the center console, and is connected to the evaporator side of the heater unit with a duct. The evaporator side of the heater unit has a cool box control motor and a shut valve. The shut valve allows cool air to flow from the evaporator into the cool box. The shut valve is driven by the cool box control motor which is controlled by the climate control unit.
Cool Box Control Switch OFF Operation
When the cool box switch is off, the shut valve closes preventing air from entering into the cool box.
Cool Box Control Switch ON Operation
When the cool box switch is on, the shut valve opens and the indicator light in the switch comes on. If the A/C compressor is not currently operating, the shut valve remains open to allow cool air to enter the cool box.
Cool Box State Memory
The climate control unit receives its power supply from the battery all the time to memorize the state of the cool box before turning the ignition switch to LOCK (0) and reproduce the same state when turning the ignition switch to ON (II) within one hour.
Seat Heater Switch
The driver's seat heater switch and front passenger's seat heater switch is in the climate control unit. The climate control unit sends a seat heater switch signal on/off to the seat heater control unit using the B-CAN line.
Climate Control Unit Inputs and Outputs
CONNECTOR A
Climate Control Unit Inputs and Outputs
CONNECTOR A
Climate Control Unit Inputs and Outputs
CONNECTOR B
