Component Description
HVAC Control Module - Dual Automatic Temperature Control (DATC)
For vehicles equipped with Sony® sound, the Dual Automatic Temperature Control (DATC) system uses voice commands or the touchscreen to control the system. For vehicles without Sony® sound, the HVAC control module is the only control interface. For details on the HVAC control module communication, refer to Control System Logic .
Blower Motor
The blower motor pulls air from the air inlet and forces it into the heater core and evaporator core housing and the plenum chamber where it is mixed and distributed.
Blower Motor Speed Control
The blower motor speed control uses a PWM signal from the HVAC control module to determine the desired blower speed and varies the ground feed for the blower motor to control the speed.
Exhaust Manifold and Catalytic Converter Assembly with Coolant Passages
HEV is equipped with an Exhaust Manifold and Catalytic Converter Assembly with coolant passages to heat engine coolant more rapidly, speeding up passenger compartment heating in cold temperatures. For engine cooling flow diagrams, Refer to: ENGINE COOLING - COMPONENT LOCATION .
Evaporator Core
The evaporator core is an aluminum plate/fin type and is located in the heater core and evaporator core housing. A mixture of liquid refrigerant and oil enters the bottom of the evaporator core through the evaporator core inlet tube and continues out of the evaporator core through the evaporator core outlet tube as a vapor. During A/C electric compressor operation, airflow from the blower motor is cooled and dehumidified as it flows through the evaporator core fins.
Heater Core
The heater core consists of fins and tubes arranged to extract heat from the engine coolant and transfer it to air passing through the heater core.
Heater Core and Evaporator Core Housing
The heater core and evaporator core housing directs airflow from the blower motor through the evaporator core and heater core. All airflow from the blower motor passes through the evaporator core. The airflow is then directed through or around the heater core by the temperature door(s). After passing through the heater core, the airflow is distributed to the selected outlet by the airflow mode doors.
Door Actuator - Air Inlet
The air inlet door actuator is a stepper motor style actuator. The HVAC control module monitors the position of the door by counting the motor steps as it rotates. The HVAC control module drives the actuator motor in the direction necessary to move the door to the position set by the recirculation button and the in-vehicle temperature and humidity sensor information.
Temperature Door Actuator - Driver Side
The driver side temperature door actuator is a stepper motor style actuator. The HVAC control module monitors the position of the temperature door by counting the motor steps as it rotates. The HVAC control module drives the temperature door actuator motor in the direction necessary to move the temperature door to the position set by the vehicle occupant.
Temperature Door Actuator - Passenger Side
The passenger side temperature door actuator is a stepper motor style actuator. The HVAC control module monitors the position of the temperature door by counting the motor steps as it rotates. The HVAC control module drives the temperature door actuator motor in the direction necessary to move the temperature door to the position set by the vehicle occupant.
Door Actuator - Footwell Vent
The footwell vent door actuator is a stepper motor style actuator. The HVAC control module monitors the position of the door by counting the motor steps as it rotates. The HVAC control module drives the actuator motor in the direction necessary to move the doors to the position set by the vehicle occupants.
Door Actuator - Defrost/Vent Register
The defrost/vent door actuator is a stepper motor style actuator. The HVAC control module monitors the position of the door by counting the motor steps as it rotates. The HVAC control module drives the actuator motor in the direction necessary to move the doors to the position set by the vehicle occupants.
Air Conditioning (A/C) Pressure Transducer
The PCM monitors the discharge pressure measured by the A/C pressure transducer. As the refrigerant pressure changes, the resistance of the A/C pressure transducer changes. It is not necessary to recover the refrigerant before removing the A/C pressure transducer.
In-Vehicle Temperature And Humidity Sensor
The in-vehicle temperature and humidity sensor contains a thermistor and a sensing element which separately measures the in-vehicle air temperature and the humidity, then sends those readings to the HVAC control module to adjust the actuator doors. The in-vehicle temperature and humidity sensor has an electric fan within the sensor that draws in-vehicle air across the two sensing elements. If the vehicle cabin becomes too humid the HVAC control module adjusts the air inlet door to allow more fresh air. When the humidity level drops, it adjusts back to recirculated air.
Sunload Sensor
The sunload sensor supplies information to the HVAC control module indicating the intensity of the sun on the vehicle.
Evaporator Temperature Sensor
The evaporator temperature sensor contains a thermistor. The sensor varies its resistance with the temperature. As the temperature rises, the resistance falls. As the temperature falls, the resistance rises. The evaporator temperature sensor is an input to the BCM and the information is relayed over the CAN. If the temperature is below a predetermined value, the SOBDMC does not allow the A/C electric compressor to operate.
Internal Heat Exchanger (IHX)
The Evaporator inlet and outlet manifold incorporates the Internal Heat Exchanger (IHX) and is serviced as an assembly. The Internal Heat Exchanger (IHX) combines a section of the A/C suction and liquid refrigerant lines into one component. It uses the cold vapor from the evaporator to cool the hot liquid from the condenser before it enters the Thermostatic Expansion Valve (TXV). After the Thermostatic Expansion Valve (TXV), more liquid refrigerant is available for absorbing heat in the evaporator. The result is an increase in cooling and operating efficiency of the HVAC system.
A/C Electric Compressor
Refer to: Refrigerant Oil Adding .
The variable-speed A/C electric compressor and the ACCM are powered by the high-voltage battery system. The ACCM is an integral part of the A/C electric compressor and cannot be removed from or serviced separately. The A/C electric compressor allows for A/C operation to continue even when the vehicle is in full electric mode and the gasoline engine is not running.
Thermostatic Expansion Valve (TXV)
The Thermostatic Expansion Valve (TXV) is located at the evaporator core inlet and outlet tubes at the center rear of the engine compartment. The TXV provides a restriction to the refrigerant flow and separates the low-pressure and high-pressure sides of the refrigerant system. Refrigerant entering and exiting the evaporator core passes through the TXV through 2 separate flow paths. An internal temperature sensing bulb senses the temperature of the refrigerant flowing out of the evaporator core and adjusts an internal pin-type valve to meter the refrigerant flow into the evaporator core. The internal pin-type valve decreases the amount of refrigerant entering the evaporator core at lower temperatures and increases the amount of refrigerant entering the evaporator core at higher temperatures.
Air Conditioning (A/C) Condenser
The A/C condenser is an aluminum fin-and-tube design heat exchanger. It cools compressed refrigerant gas by allowing air to pass over fins and tubes to extract heat, and condenses gas to liquid refrigerant as it is cooled.
Receiver Drier
The receiver drier stores high-pressure liquid and the desiccant bag mounted inside the receiver drier removes any retained moisture from the refrigerant.
The receiver drier element is incorporated onto the LH side of the A/C condenser. The receiver drier element can be separately removed and installed with the A/C condenser removed from the vehicle.
Service Gauge Port Valves
| Item | Description | Torque |
|---|---|---|
| 1 | Low-pressure service gauge port valve cap | 0.8 Nm (7 lb-in) |
| 2 | Low-pressure service gauge port valve | - |
| 3 | Low-pressure Schrader-type valve | 2.26 Nm (20 lb-in) |
| 4 | High-pressure Schrader-type valve | 3.4 Nm (30 lb-in) |
| 5 | High-pressure service gauge port valve | - |
| 6 | High-pressure service gauge port valve cap | 0.8 Nm (7 lb-in) |
The service gauge port valve is an integral part of the refrigerant line or component.
- Prior to leak testing, blow air over service gauge port valves to insure an accurate test.
- Special couplings are required for both the high-side and low-side service gauge ports.
- A very small amount of leakage around the Schrader-type valve with the service gauge port valve cap removed is considered normal. Install a new Schrader-type valve core if the seal leaks excessively.
- The A/C service gauge port valve caps are used as primary seals in the refrigerant system to prevent leakage through the Schrader-type valves from reaching the atmosphere. Always install and tighten the A/C service gauge port valve caps to the correct torque after they are removed.
- Follow the procedure and the notes for electronic leak testing. Refer to: Electronic Leak Detection .
Refrigerant System Dye
A fluorescent refrigerant system dye wafer is added to the receiver drier desiccant bag at the factory to assist in refrigerant system leak diagnosis. This fluorescent dye wafer dissolves after about 30 minutes of continuous A/C operation. It is not necessary to add additional dye to the refrigerant system before diagnosing leaks, even if a significant amount of refrigerant has been removed from the system. Refer to: Fluorescent Dye Leak Detection .