AIR CONDITIONING SYSTEM

FUNCTION OF MAIN COMPONENTS

Component	Function
Air Conditioning Amplifier Assembly	Transmits and receives data to and from the switches and sensors, and controls the air conditioning system, seat heater system1, rear seat heater system2 climate control seat system3, rear climate control seat system4 and steering wheel heater system*5.
Cooler Thermistor (Room Temp. Sensor)	Detects the internal temperature inside the cabin and outputs that data to the air conditioning amplifier assembly.
Rear Room Temperature Sensor (Cooler Thermistor)*6
Ambient Temperature Sensor (Thermistor Assembly)	Detects the ambient temperature and outputs it to the air conditioning amplifier assembly.
Solar Sensor (Automatic Light Control Sensor)	Detects the changes in the amount of solar energy and outputs them to the main body ECU (multiplex network body ECU).
Cooler Thermistor (Solar Sensor)*6	Detects the changes in the amount of solar energy and outputs them to the air conditioning amplifier assembly.
Multi-display	Displays the settings screen.
Radio Receiver Assembly	Sends function customization information from the multi-display setting screen to the air conditioning amplifier assembly.
Main Body ECU (Multiplex Network Body ECU)	Sends solar energy level difference, signals to the air conditioning amplifier assembly.
Seat Heater Control Sub-assembly RH (Front)*1	Controls the seat heater according to signals from the air conditioning amplifier assembly.
Seat Heater Control Sub-assembly LH (Front)*1
Seat Heater Control Sub-assembly LH (Rear)*2
Seat Heater Control Sub-assembly RH (Rear)*2
Seat Cushion Climate Control Blower Assembly LH (Front)*3	Operates the blower according to signals from the air conditioning amplifier assembly and supplies air to the seat cushion. Sends operation signals to the seatback climate control blower assembly.
Seat Cushion Climate Control Blower Assembly RH (Front)*3
Seat Back Climate Control Blower Assembly LH (Front)*3	Operates the blower according to signals from the seat cushion climate control blower assembly and supplies air to the seatback.
Seat Back Climate Control Blower Assembly RH (Front)*3
Seat Cushion Climate Control Blower Assembly LH (Rear)*4	Operates the blower according to signals from the seat cushion climate control blower assembly and supplies air to the seatback. Operates the blower according to signals from the seat cushion climate control blower assembly and supplies air to the seatback.
Seat Cushion Climate Control Blower Assembly RH (Rear)*4
Seat Back Climate Control Blower Assembly LH (Rear)*4	Operates the blower according to signals from the rear seat cushion climate control blower assembly and supplies air to the seat back.
Seat Back Climate Control Blower Assembly RH (Rear)*4
Steering Vibration and Heater ECU*5	Controls the steering wheel heater according to signals from the air conditioning amplifier assembly and the thermistor built into the steering wheel assembly.
Air Conditioning Control Assembly	Allows operation and adjustment of the air conditioning via switches.
Combination Meter Assembly	Sends the passenger side occupant detection signal to the air conditioning amplifier assembly.
Rear Multiplex network Door ECU LH	Sends internal temperature inside the cabin, signals to the air conditioning amplifier assembly.
Rear Multiplex network Door ECU RH
Central Gateway ECU (Multiplex Network Body ECU)	Relays the signal between the CAN communication lines.

*1: Models with seat heater system

*2: Models with rear seat heater system

*3: Models with climate control seat system

*4: Models with Rear climate control seat system

*5: Models with Steering wheel heater system

*6: Models with multi-zone (4-ZONE) climate control

SYSTEM CONTROL
1. Seat Heater System and Climate Control Seat System Operation (Models with Seat Heater System or Climate Control Seat System)
  1. With Lexus Climate Concierge control, the seat heater level and climate control seat level are changed in steps based on the ambient temperature and target output temperature for the driver side and front passenger side so that the levels are optimized constantly.
  2. Lexus Climate Concierge control is performed in 9 steps: 5 steps for the seat heater level (Lo1, Lo2, Medium1, Medium2 and Hi), 3 steps for the climate control seat system and 1 step for OFF.
  3. For the front passenger side, the seat heater system and climate control seat system perform automatic operations when a passenger is detected by the occupant detection system. The seat heater system and climate control seat system stop the AUTO operation when the occupant detection system judges that there is no passenger in the front passenger seat. The AUTO operation is resumed when the occupant detection system is operated again and judges that there is a passenger.*
    
    Tech Tips
    
    *: Occupant detection system is not performed if the seat heater system and climate control seat system perform automatic operations with the AUTO switch on the SEAT/STEERING screen.
2. Steering Wheel Heater System Operation (Models with Steering Wheel Heater System)
  1. With Lexus Climate Concierge control, the steering wheel heater level is changed in steps based on the ambient temperature and target output temperature of the driver side so that the level is optimized constantly.
  2. Lexus Climate Concierge control adjusts the steering wheel heater level in 3 steps (Hi, Lo and OFF).

FUNCTION

When the air conditioning system, seat heater system*1, rear seat heater system*2 climate control seat system*3, rear climate control seat system*4 and steering wheel heater system*5 are operating in AUTO mode, the air conditioning amplifier assembly comprehensively controls the systems to achieve a comfortable space in the cabin.
When the system is in heater mode, the air conditioning amplifier assembly operates the seat heater system*1, rear seat heater system*2 and steering wheel heater system*5, and when the system is in cooler mode, the air conditioning amplifier assembly operates the climate control seat system*3 and rear climate control seat system*4. The air conditioning amplifier assembly operates the systems according to the ambient temperature and cabin temperature. Also, the seat heater system*1, rear seat heater system*2, climate control seat system*3 and rear climate control seat system*4 are combined to reduce the load on the air conditioning system, improving fuel economy without sacrificing passenger comfort.
A Lexus Climate Concierge monitor is used, making it possible to check the operation conditions of the air conditioning system, seat heater system*1, rear seat heater system *2, climate control seat system*3, rear climate control seat system*4 and steering wheel heater system*5.

A Lexus Climate Concierge switch is positioned on the Lexus Climate Concierge monitor and used to make it possible to set the air conditioning system, seat heater system*1, rear seat heater system*2, climate control seat system*3, rear climate control seat system*4 and steering wheel heater system*5 to AUTO mode*6 all at once.

Tech Tips

*1: Models with seat heater system

*2: Models with rear seat heater system

*3: Models with climate seat control system

*4: Models with rear climate seat control system

*5: Models with steering wheel heater system

*6: AUTO mode can be set individually for each system.

Figure 1. Lexus Climate Concierge Monitor

*A	Lexus Climate Concierge Monitor (Front)	*B	Lexus Climate Concierge Monitor (Rear)
*C	Models with Rear Seat Heater System or Rear Climate Control Seat System	-	-
*1	Lexus Climate Concierge (LCC) Switch	-	-
*a	The illustration shown are example only.	-	-

Figure 2. Option Display and Setting Display

*A	Option Display	*B	Setting Display
*1	Lexus Climate Concierge (LCC) Switch	-	-
*a	The illustration shown are example only.	-	-