1. Prius PHV
Air Conditioning
Toyota Motor Europe

2. Overview : Available —: Not Available Items PRIUS Plug-in PRIUS
Heater Control Panel
Automatic A/C 
A/C Unit
Some of air is always re-circulated
Plasmacluster Generator (-A Only) —
Heater
SFA (Straight Flow Aluminum) -II Heater Core
PTC Heater
165 W x 3
280 W x 3
Heat Pump System
Electric Water Pump (for Heater and Engine Cooling)
Compressor
Scroll Type Compressor with Motor
(A/C Inverter integrated)
ES14
ES27
Compressor Oil: ND-OIL11
Compressor capacity is increased to reduce compressor speed and noise.

3. Overview : Available —: Not Available Items PRIUS Plug-in PRIUS
Condenser
MF-IV Sub-cool Condenser
in Engine Compartment 
in A/C Unit —
Evaporator
ECS (Ejector Cycle System) Evaporator
Servo Motor
Pulse Detection Type Servo Motor with Bus Connector
Blower
Brushless Motor
Models with Solar Power Ventilation System
for All Models
Clean Air Filter
Pollen Removal Type
Sensor
Humidity Sensor
Refrigerant
HFC134a
Control
Solar Ventilation System Control
Remote Air Conditioning System Control
Cooling Operation
Heating Operation
Eco Mode Control

4. Heat Pump System Plug-in Hybrid with Heat Pump System
Start
Goal
Heater ON
EV Driving
Plug-in Hybrid with Heat Pump System
The heat pump system (electric energy) is used when the engine is cold
Engine is warmed-up only for the heating operation
(It lowers fuel economy)
EV Driving
Plug-in Hybrid without Heat Pump System

5. Heat Pump System System Diagram Dehumidification Magnetic Valve
High Pressure Magnetic Valve
Heating 3-way Valve
Accumulator
Refrigerant Outlet Temp. Sensor
Orifice
A/C Pressure Sensor
Heat Exchanger Shut Valve
Low Pressure Magnetic Valve
Engine M H C
Condenser C E
Refrigerant Inlet Temp. Sensor
Heater Core
The accumulator functions as gas-liquid separator.
Condenser
Air Mix Damper
Compressor with Motor
ECS Evaporator
Expansion Valve
Electric Water Pump
A/C Unit

6. Heat Pump System Parts location A/C Unit (RHD Model) PTC Heater
Condenser
Heater Core
ECS Evaporator
Blower Motor
A/C Unit (RHD Model)

7. Heat Pump System Parts location Refrigerant Outlet Temp. Sensor
A/C Unit
A/C Pressure Sensor
Expansion Valve
Compressor with Motor
Dehumidification Magnetic Valve
Heating 3-way Valve
Accumulator
Condenser
High Pressure Magnetic Valve
Low Pressure Magnetic Valve
Heat Exchanger Shut Valve
Refrigerant Inlet Temp. Sensor

8. Heat Pump System Refrigerant line (All) E H M M H C E: Evaporator
C: Condenser
H: Heater Core
M: Compressor with Motor C E A
Condenser
A/C Unit
View from A

9. Refrigerant Outlet Temp. Sensor
Heat Pump System
Refrigerant line (1/3) E C H M M H C
A/C Pressure Sensor
E: Evaporator
C: Condenser
H: Heater Core
M: Compressor with Motor C E
Refrigerant Outlet Temp. Sensor
Compressor with Motor
Heating 3-way Valve

10. Heat Pump System Refrigerant line (2/3) E H M H C M E: Evaporator
C: Condenser
H: Heater Core
M: Compressor with Motor C E
Expansion Valve
Heat Exchanger Shut Valve
Dehumidification Magnetic Valve
High Pressure Magnetic Valve

11. Heat Pump System Refrigerant line (3/3) E H M H C M E: Evaporator
C: Condenser
H: Heater Core
M: Compressor with Motor C E
Refrigerant Inlet Temp. Sensor
Accumulator
Low Pressure Magnetic Valve

12. Heat Pump System Cooler cycle Close Open OFF Open Close Engine M H C E
Cooled Air C
[Cooler Cycle]
Evaporator: Heat-absorbing
Condenser (in Engine Compartment): Heat Dissipation
Condenser (in A/C Unit): Heat Dissipation
High Pressure Magnetic Valve: Open (OFF)
Low Pressure Magnetic Valve: Close (OFF)
Dehumidification Magnetic Valve: Close (OFF)
Heat Exchanger Shut Valve: Open (OFF)
Heating 3-way Valve: OFF
NOTE: In the cooler cycle, all magnetic valves are OFF.
E: Evaporator
C: Condenser
H: Heater Core
M: Compressor with Motor
A/C Unit

13. Heat Pump System Heat Pump Cycle Close Close ON Open Open Warmed Air
Engine M H C C E
[Heat Pump Cycle] Dehumidification Valve
Evaporator: Nonfunctional
Condenser (in Engine Compartment): Heat-absorbing
Condenser (in A/C Unit): Heat Dissipation
High Pressure Magnetic Valve: Close (ON)
Low Pressure Magnetic Valve: Open (ON)
Dehumidification Magnetic Valve: Close (OFF)
Heat Exchanger Shut Valve: Open (OFF)
Heating 3-way Valve: ON
E: Evaporator
C: Condenser
H: Heater Core
M: Compressor with Motor
A/C Unit

14. Warmed and Dehumidified Air
Heat Pump System
Heat Pump Cycle (With dehumidification) [A]
Open
Close ON
Close
Close
Warmed and Dehumidified Air
Engine M H C C E
[Heat Pump Cycle (with Dehumidification) [A]]
Evaporator: Heat-absorbing
Condenser (in Engine Compartment): Nonfunctional
Condenser (in A/C Unit): Heat Dissipation
High Pressure Magnetic Valve: Close (ON)
Low Pressure Magnetic Valve: Close (OFF)
Dehumidification Magnetic Valve: Open (ON)
Heat Exchanger Shut Valve: Close (ON)
Heating 3-way Valve: ON
E: Evaporator
C: Condenser
H: Heater Core
M: Compressor with Motor
A/C Unit

15. Warmed and Dehumidified Air
Heat Pump System
Heat Pump Cycle (With dehumidification) [B]
Open
Close ON
Open
Open
Warmed and Dehumidified Air
Engine M H C C E
[Heat Pump Cycle (with Dehumidification) [B]]
Evaporator: Heat-absorbing
Condenser (in Engine Compartment): Heat-absorbing
Condenser (in A/C Unit): Heat Dissipation
High Pressure Magnetic Valve: Close (ON)
Low Pressure Magnetic Valve: Open (ON)
Dehumidification Magnetic Valve: Open (ON)
Heat Exchanger Shut Valve: Open (OFF)
Heating 3-way Valve: ON
E: Evaporator
C: Condenser
H: Heater Core
M: Compressor with Motor
A/C Unit

16. Heat Pump System Heating operation by engine coolant Close Open OFF
Warmed Air
Engine M H C C E
[Heating Operation by Engine Coolant]
Heater Core: Heat Dissipation
Evaporator: Nonfunctional
Condenser (in Engine Compartment): Nonfunctional
Condenser (in A/C Unit): Nonfunctional
High Pressure Magnetic Valve: Open (OFF)
Low Pressure Magnetic Valve: Close (OFF)
Dehumidification Magnetic Valve: Close (OFF)
Heat Exchanger Shut Valve: Open (OFF)
Heating 3-way Valve: OFF
NOTE: A/C system is cooler cycle when heating by engine coolant.
E: Evaporator
C: Condenser
H: Heater Core
M: Compressor with Motor
Electric Water Pump
A/C Unit

17. with Dehumidification
Heat Pump System
Heat Pump Operating Conditions
Heat Pump
The heating performance by the current coolant temp. is lower than the target heating performance
Heat Pump Cycle
Windshield glass is hard to fog up
A/C switch indicator is turned off by pressing A/C switch
Windshield glass is easy to fog up (with A/C switch indicator ON)
Engine Coolant
The heating performance by the current coolant temp. is higher than the target heating performance
Front DEF switch is pressed (with windshield glass is easy to fog up)
Temp. setting is MAX HOT
Ambient temp. is approx. –2 °C (28.4 °F) or less
Frost is detected at the condenser (in the engine compartment)
with Dehumidification
Heat Pump Cycle
(with Dehumidification) [A]
A humidity sensor is used in order to calculate the easiness of the windshield glass fog up.
In the heat pump cycle, there is a possibility that the condenser (in the engine compartment) frosts under the subfreezing temperature. This causes the decrease of the heat transfer efficiency and an enough heating performance cannot be secured. Therefore, the heat pump cannot be used when the ambient temp. is approx. –2 °C (28.4 °F) or less.
[Dehumidification [A] and [B]]
Dehumidification [A] and [B] are switched in accordance with the evaporator temperature. At first, the dehumidification [A] is used. When the heating load becomes high, it is necessary to raise the discharge pressure of the compressor to increase heating performance. At this time, refrigerant flow volume in the evaporator increases. As a result, the evaporator temp. decreases below zero and the frost is formed at evaporator. In order to prevent this, the heat pump cycle is changed to the dehumidification [B] when the evaporator temp. decreases. In the dehumidification [B], the refrigerant flow to the condenser (in the engine compartment) is added and the flow volume in the evaporator decreases. Therefore, the decrease in the temperature of the evaporator can be suppressed.
Less than 2.5 °C (36.5 °F)
2.5 °C (36.5 °F) or more
Evaporator temp.
Heat Pump Cycle
(with Dehumidification) [B]

18. Heat Pump System Automatic Defrosting Operation A/C Amplifier
Refrigerant Inlet Temp. Sensor Signal
Approx. –15 °C (5 °F) or less continues for 30 sec.
Heat Pump Cycle
Start request
Engine
Judges that the condenser (in the engine compartment) is frosted
Warmed up
Heating operation is changed from heat pump type to engine coolant type
Changes to cooler cycle in order to defrost the condenser (for 20 min.)
When the condition that the refrigerant inlet temp. is approx. –15 °C (5 °F) or less continues for 30 sec. or more, the A/C amplifier judges that the condenser (in the engine compartment) is frosted. At this time, engine is started. After the engine is warmed up, A/C cycle is changed to cooler cycle to defrost the frosted condenser (in the engine compartment). This defrosting operation is performed for 20 min. During this time, the heating operation is performed by the warmed engine coolant.
Required Flow Volume of the Electric Water Pump
Cooler Cycle

19. [with dehumidification] [without dehumidification]
Heat Pump System
A/C switch indicator
A/C Switch Indicator
A/C System
Cooler Cycle
Heat Pump Cycle ON
Compressor ON
[with dehumidification]
(Automatically dehumidified if necessary)
OFF
Compressor OFF
[without dehumidification]
During cooler cycle, ON/OFF condition of the A/C switch indicator shows the compressor ON/OFF condition.
During heat pump cycle, ON/OFF condition of the A/C switch indicator shows the system condition whether the dehumidification operation is possible.
ON: The dehumidification operation is automatically performed when it is necessary.
OFF: The dehumidification operation is not performed even if the windshield glass is easy to fog up.
NOTE: ON/OFF condition of the A/C switch indicator (= system condition whether the dehumidification operation is possible or not) can be changed by pressing the A/C switch.
A/C Switch

20. Easiness of the windshield glass fog up
Heat Pump System
Humidity Sensor
Glass Humidity
Glass Temp.
Glass Surroundings Temp.
A/C Amplifier
Easiness of the windshield glass fog up
Controls A/C system
Humidity Sensor
Glass Humidity Sensor
Glass Temp. Sensor
Glass Surroundings Temp. Sensor
A newly developed humidity sensor consists of the glass humidity sensor, glass temp. sensor and glass surroundings temp. sensor. The output signal of these sensors is used for the calculation of the easiness of the windshield glass fog up.
Energy loss reduced
Prevents windshield glass from fogging up

21. Heat Pump System Humidity sensor controls Air Inlet Mode Control
Easiness of the windshield glass fog up
Air Inlet Mode Control
Air Outlet Mode Control
Airflow Volume Control
Hard to fog up
Easy to fog up
FRE 100%
Increase FER Air
Keep REC/FRE ratio
Increase REC Air
FOOT/DFF Mode
Normal Control +5
[Air Inlet Mode Control]
Increase circulated air volume in the range where the windshield glass does not fog up to reduce the energy loss.
When the windshield glass is easy to fog up, the system increases fresh air volume to prevent windshield glass from fogging up.
[Air Outlet Mode Control]
When the windshield glass is easy to fog up, the system changes the air outlet mode to FOOT/DEF mode to prevent windshield glass from fogging up.
[Airflow Volume Control]
When the windshield glass is easy to fog up, the system increases airflow volume to prevent windshield glass from fogging up.
Blower Level +1 ±0

22. Remote Air Conditioning System
Activation
Press and Hold
Electric power supplied through the plug-in function
Major Difference From PRIUS
[Following precautions are the same as PRIUS]
Vehicles with the remote air conditioning system have the following risks that it is necessary to be aware of when performing repairs. Therefore, make sure to take care of the key (electrical transmitter) carefully so that the remote air conditioning system is not operated unexpectedly.
[Risks]
- The electrical fan and other items in the engine compartment may operate resulting in various hazards.
- The wipers may operate if the wiper switch is in the on position when the remote air conditioning system is activated. If this occurs, there is the potential for damage to the glass, wipers or injury.
- When the light control switch is in the tail, head or AUTO position, the headlights may turn on.
- Short circuits may occur if electrical inspections are being performed when the remote air conditioning system is turned on, because the IG circuit is powered at this time.
Model
PRIUS Plug-in
PRIUS
Operation
Cooling and Heating
Cooling only
Operating Condition
While plug-in charging
While power mode OFF
Power Supply
Supplied through the plug-in function
HV Battery
Solar Ventilation System
N.A.
Equipped

23. Remote Air Conditioning System
System Diagram
Battery Charger
Battery Charger Inlet
HV Battery (Sub 1, 2)
Charger Relay
HV Battery (Main)
High-voltage Wire Harness
Boost Converter (Sub)
HV Battery Assembly
Power Switch
Shift Position Sensor
Stop Light Switch
Boost Converter (Main)
DC-DC Converter
Inverter Assembly
IG1, IG2 Relays
Compressor with Motor
Room Temp. Sensor
Power Management Control ECU
Ambient Temp. Sensor
Door Control Receiver
Certification ECU
Power Management Bus
V Bus No.1
Solar Sensor
A/C Amplifier
Main Body ECU
Blower Motor
Remote Air Conditioning Switch
Servo Motors
Door Courtesy Light Switch
Door Lock Position Switch
Hood Courtesy Switch
PTC Heater

24. Remote Air Conditioning System
Operating Conditions
Operation Start Condition
Press and hold the remote air conditioning switch for 0.8 sec or more when all the following conditions are satisfied
Power mode is OFF
Power switch is not pressed
Shift position is in P
All the doors are closed and locked
Engine hood is closed
Brake pedal is not depressed
Theft deterrent system is not in alarm state
While plug-in charging
Cooling or heating operating conditions meet the set temperature
[Following operations are the same as PRIUS]
When the remote air conditioning system is activated, the wireless door lock is also activated, blinking the hazard lights once and sounding the wireless door lock buzzer once, thus improving anti-theft performance and informing the user of the operating state.
When the remote air conditioning system is deactivated by the remote air conditioning switch, the hazard lights blink twice and the wireless door lock buzzer sounds twice, informing the user of the operating state.
Operation Stop Condition [OR]
When the operation start condition are not met
Approx. 30 min. have elapsed
When the remote air conditioning switch is pressed twice within 3 sec.

25. Remote Air Conditioning System
Operation
Operation start conditions are satisfied
A/C system operates in accordance with the set temp.
Heating Operation
Cooling Operation
Ambient Temp.
-2 °C (28.4 °F) or more
Less than
-2 °C (28.4 °F)
During operation, the set temperature before the power mode off is used for the A/C operation.
Because there is a possibility that the condenser (in the engine compartment) frosts under the subfreezing temperature during the heat pump cycle, the PTC heater is used when the ambient temp. is less than –2 °C (28.4 °F).
Heat Pump
(Heating Cycle)
PTC
Heater
Maximally 3 PTC heaters (280 W x 3) are operated in accordance with the max. permissible power

26. Air Conditioning System
Refrigerant
PRIUS Plug-in: 670 g (23.6 oz.)
PRIUS: 470 g (16.6 oz.)
Standard Refrigerant Amount
100 g
(3.53 oz.)
High Pressure
Overcharged
+/- 50 g
(+/ oz.)
Point where bubbles disappear
Refrigerant Amount