cooling LEXUS RX450h 2015 Owners Manual

331-1. Hybrid system
1
Before driving ■
Sounds and vibrations specific to a hybrid vehicle
There may be no engine sounds or vibration even though the vehicle is able to
move. Always shift the shift lever to P when parked.
The following sounds or vibrations may o ccur when the hybrid system is operating,
and are not a malfunction: ●
Motor sounds may be heard fr om the engine compartment.●
Sounds may be heard from the hybrid battery (traction battery) under the rear
seat when the hybrid system starts or stops.●
Sounds from the hybrid system may be heard when the back door is open.●
Sounds may be heard from the hybrid transmission when the engine is started
or stopped, or while the engine is idling.●
Engine sounds may be heard when accelerating sharply.●
Sounds may be heard due to regenerative braking when the brake pedal is
depressed and accelerator is loosened.●
Vibration may be felt when the gasoline engine starts or stops.●
Cooling fan sounds may be heard from th e air intake vents un der the rear seat.■
Vehicle Proximity Notification System
In the following cases, the Vehicle Proximit y Notification System sound may be diffi-
cult for pedestrians, people riding bicycles or other peop le and vehicles in the sur-
rounding area to hear: ●
When there is a lot of noise in the vicinity ●
When it is raining or during strong winds●
When in the area surrounding the rear of the vehicle, rather than in front of the
vehicle■
Maintenance, repair, recycling, and disposal
Contact your Lexus dealer regarding main tenance, repair, recycling and disposal.
Do not dispose of the vehicle yourself.

351-1. Hybrid system
1
Before driving Hybrid battery air vents
There are air intake vents under
the rear seats for the purpose of
cooling the hybrid battery (traction
battery). If the vents become
blocked, the hybrid battery may
overheat, leading to a reduction in
hybrid battery output.
Emergency shut off system
When a certain level of impact is detected by the impact sensor, the
emergency shut off system blocks off the high voltage current and stops
the fuel pump to minimize the risk of electrocution and fuel leakage. If the
emergency shut off system activates, your vehicle will not restart. To
restart the hybrid system, contact your Lexus dealer.
Hybrid warning message
A message is automatically displayed when a malfunction occurs in the
hybrid system or an impr oper operation is attempted.
If a warning message is shown on
the multi-information display, read
the message and follow the
instructions. ( 
P. 743)

1872-1. Driving procedures
2
When driving ■ Selecting Eco drive mode
When the vehicle is driven in Eco drive mode, vehicle driving force
and operation of the air condit ioning system (heating/cooling) is
controlled to improve fuel efficiency.
Press the menu switch. The multi-information display
will change modes to electronic
features control mode.
Press the “  ” or “  ” switch
until “ECO MODE” appears.
Press the “ENTER” switch to
change to “ON”.
The “ECO MODE” indicator
will be displayed. Each pressing of the switch
turns Eco drive mode on and off.
Press the menu switch to
change to the normal display.STEP 1
STEP 2

1902-1. Driving procedures
Changing shift ranges in S mode
When the shift lever is in the S position, the shift lever can be operated as
follows:
Upshifting
Downshifting
The initial shift range in S mode is set automatically to “5” or “4” accord-
ing to vehicle speed.
■ Shift ranges and their functions
● You can choose from 6 levels of engine braking force.
● A lower shift range will provide gr eater engine braking force than a
higher shift range, and the engi ne speed will also increase.■
Operation of the air conditioning system in Eco drive mode
Eco drive mode controls the heating/cooling operations and fan speed of the air
conditioning system to enhance fuel efficiency. (  P. 342, 350) To improve air con-
ditioning performance, adjust the fa n speed or turn off Eco drive mode. ■
Automatic return to normal driving mode
If snow mode or sport mode is selected , the driving mode will automatically return
to normal mode when the hybrid system is turned off.
■
S mode
●
When the shift range is “5” or lower, holding the shift lever toward “+” sets the
shift range to “6”.
●
To prevent the engine from over-revving, upshifting may automatically occur.

3433-2. Using the air conditio ning system and defogger
3
Interior features
Using the automatic air conditioning system
Press .
The air conditioning system begins to operate. Air outlets and fan
speed are automatically adjusted according to the temperature
setting.
Press or select of the “TEMP” to increase the tempera-
ture and or to decrease the temperature.
When is selected (the indicator on is on) or the pas-
senger’s side temperature control bu tton is pressed, the temperature
for the driver and passenger seat s can be adjusted separately.
■ Automatic mode indicator
If fan speed setting or air flow modes are operated, the automatic
mode indicator goes off. However, automatic mode for functions other
than that operated are maintained.■ Automatic air conditioning system control screen
Adjusting driver’s side tem-
perature setting
Adjusting passenger’s side
temperature setting
Adjusting the fan speed
Selecting air outlet mode
Cooling and dehumidifica-
tion function on/off
Dual mode on/off
Windshield wiper de-icer on/
offSTEP 1
STEP 2

3473-2. Using the air conditio ning system and defogger
3
Interior features Front side outlets
Direct air flow to the left or right,
up or down.
Turn the knob to open or close
the vent.
Rear outlets
Direct air flow to the left or right,
up or down.
Turn the knob to open or close
the vent.
■
Operation of the air conditioning system in Eco drive mode
In Eco drive mode, the air conditioning syst em is controlled as follows to prioritize
fuel efficiency: ●
Engine speed and compressor operation controlled to restrict heating/cooling
capacity●
Fan speed restricted when automatic mode is selected
To improve air conditioning performanc e, perform the following operations:●
Adjust the fan speed
●
Turn off Eco drive mode
■
Customization
The air conditioning control of Eco drive mode can be changed to the same setting
as that used in normal drive mode.
(Customizable features  P. 825)

3493-2. Using the air conditio ning system and defogger
3
Interior features ■
When outside air temperature is below 32  F (0  C)
The cooling and dehumidification function may not operate even when
is
on.■
Ventilation and air conditioning odors ●
To let fresh air in, set the air conditioning system to the outside air mode.●
During use, various odors from inside and outside the vehicle may enter into
and accumulate in the air conditioning sy stem. This may then cause odor to be
emitted from the vents.●
To reduce potential odors from occurring:
• It is recommended that the air conditioning system be set to outside air mode
prior to turning the vehicle off.
• The start timing of the blower may be delayed for a short period of time
immediately after the air conditioning system is started in automatic mode.
CAUTION■
To prevent the windshield from fogging up
Do not use
during cool air operation in ex tremely humid weather. The dif-
ference between the temperature of the outside air and that of the windshield can
cause the outer surface of the windshield to fog up, blocking your vision.
NOTICE■
To prevent 12-volt battery discharge
Do not leave the air conditioning system on longer than necessary when the hybrid
system is off.

3503-2. Using the air conditio ning system and defogger
Automatic air conditioning system (without a navigation system or the Lexus Display Audio system)Air outlets and fan speed are automati cally adjusted according to the tem-
perature setting.
Automatic
mode
buttonDriver’s side temperature
display
Air outlet selector buttonFan speed
control
button Air outlet display Fan speed display
Passenger’s side temperature
display
Driver's side temperature
control buttons
Cooling and dehumidification function
on/off button
Outside/recirculated air mode buttonWindshield defogger
button Passenger’s side temperature control buttons Dual mode
button “OFF”
button

3553-2. Using the air conditio ning system and defogger
3
Interior features ■
Operation of the air conditioning system in Eco drive mode
In Eco drive mode, the air conditioning syst em is controlled as follows to prioritize
fuel efficiency: ●
Engine speed and compressor operation controlled to restrict heating/cooling
capacity●
Fan speed restricted when automatic mode is selected
To improve air conditioning performanc e, perform the following operations:●
Adjust the fan speed●
Turn off Eco drive mode■
Customization
The air conditioning control of Eco drive mode can be changed to the same setting
as that used in normal drive mode.
(Customizable features  P. 825)■
Air conditioning system settings ●
When the “POWER” switch is turned on, the air conditioning system settings
will be set to those that were in use the last time the “POWER” switch was
turned off.●
Air conditioning system settings are memorized individually on each electronic
key, so the settings repr oduced will be specific to the key that is used.●
This feature is customizable at your Lexus dealer.■
Using automatic mode
Fan speed is adjusted automatically accord ing to the temperature setting and ambi-
ent conditions. As a result, the following may occur:
Immediately after the button is pressed, the fan may stop for a while until warm or
cool air is ready to flow.■
Using the system in recirculated air mode
The windows will fog up more easily if recirculated air mode is used for an extended
period.
■
Switching between outside air and recirculated air modes
Recirculated air mode or outside air mode may be automatically switched in accor-
dance with the temperature setting and the inside temperature.

3563-2. Using the air conditio ning system and defogger
■
When the outside temperature exceeds 75°F (24°C) and the air conditioning
system is on ●
In order to reduce the air conditioning power consumption, the air conditioning
system may switch to recirculated air mode automatically. This may also reduce
fuel consumption.●
Recirculated air mode is selected as a default mode when the “POWER” switch
is turned to ON mode.●
It is possible to switch to outside air mode at any time by pressing .■
Window defogger feature
Recirculated air mode may automatically switch to outside air mode in situations
where the windows need to be defogged.■
When outside air temperature is below 32  F (0  C)
The cooling and dehumidification fu nction may not operate even when
is
pressed.■
When the indicator light on goes off
Press to turn on the cooling and dehumi dification function again. There may
be a problem in the air conditioning system if the indicator light goes off again
shortly after the button is pressed. Have it inspected by your Lexus dealer.■
Ventilation and air conditioning odors ●
To let fresh air in, set the air conditioning system to the outside air mode.●
During use, various odors from inside and outside the vehicle may enter into
and accumulate in the air conditioning sy stem. This may then cause odor to be
emitted from the vents.●
To reduce potential odors from occurring:
• It is recommended that the air conditioning system be set to outside air mode
prior to turning the vehicle off.
• The start timing of the blower may be delayed for a short period of time
immediately after the air conditioning system is started in automatic mode.