2015 Lexus IS300h cooling

821-2. Hybrid system
IS300h_EE(OM53D56E)
■After the 12-volt battery has discharged or has been changed or removed
The gasoline engine may not stop even if the vehicle is being driven by the hybrid battery
(traction battery). If this continues for a few days, contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
■Sounds and vibrations specific to a hybrid vehicle
There may be no engine sound or vibration even though the vehicle is able to move. For
safety, apply the parking brake and make sure to shift the shift lever to P when parked.
The following sounds or vibrations may occu r when the hybrid system is operating and
are not a malfunction:
●Motor sounds may be heard from under the vehicle.
●Sounds may be heard from the hybrid battery (traction battery) behind the rear seats
when the hybrid system starts or stops.
●Sounds from the hybrid system may be heard when the trunk lid is open.
●Sounds may be heard from the hybrid transmission when the hybrid system starts or
stops.
●Engine sounds may be heard when accelerating sharply.
●Sounds may be heard due to regenerative braking when the brake pedal is depressed.
●Vibration may be felt when the gasoline engine starts or stops.
●Cooling fan sounds may be heard from the air intake vents on the both sides of the rear
seatback.
■Maintenance, repair, recycling, and disposal
Contact any authorized Lexus dealer or repa irer, or another duly qualified and equipped
professional regarding maintenance, repair, re cycling and disposal. Do not dispose of the
vehicle yourself.
■Customization
Settings (e.g. on/off operation of the EV indicator) can be changed.
(Customizable features →P. 5 9 1 )

841-2. Hybrid system
IS300h_EE(OM53D56E)
There is an air intake vent on the right
side of the rear seatback for the pur-
pose of cooling the hybrid battery
(traction battery). If the vent becomes
blocked, the hybrid battery may over-
heat, leading to a reduction in hybrid
battery output.
When a certain level of impact is detected by the impact sensor, the emergency
shut off system blocks the high voltage current and stops the fuel pump to mini-
mize 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 any
authorized Lexus dealer or repairer, or another duly qualified and equipped pro-
fessional.
A message is automatically displayed when a malfunction occurs in the hybrid
system or an improper operation is attempted.
If a warning message is shown on the
multi-information display, read the
message and follow the instructions.
(→P. 5 2 7 )
Hybrid battery (traction battery) air vent
Emergency shut off system
Hybrid warning message

2954-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D56E)
■Operation of the air conditioning system in Eco drive mode
Eco drive mode controls the heating/cooling operations and fan speed of the air condi-
tioning system to enhance fuel efficiency ( →P. 412). To improve air conditioning perfor-
mance, adjust the fan speed or turn off Eco drive mode.
■Sport mode automatic deactivation
Sport mode is automatically deactivated if th e power switch is turned off after driving in
sport mode.

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IS300h_EE(OM53D56E)4-6. Driving tips
■Using Eco drive mode
When using Eco drive mode, the torque corresponding to the accelerator
pedal depression amount can be generated more smoothly than it is in normal
conditions. In addition, the operation of the air conditioning system (heating/
cooling) will be minimized, improving the fuel economy. (
→P. 2 9 3 )
■Use of Hybrid System Indicator
Eco-friendly driving is possible by keeping the indicator needle (except F
SPORT models) or bar display (F SPORT models) of Hybrid System Indicator
within the Eco area. ( →P. 1 1 3 )
■When braking
Make sure to operate the brakes gently and in good time. A greater amount
of electrical energy can be regenerated when slowing down.
■Delays
Repeated acceleration and deceleration, as well as long waits at traffic lights,
will lead to bad fuel economy. Check traffic reports before leaving and avoid
delays as much as possible. When driving in a traffic jam, gently release the
brake pedal to allow the vehicle to move forward slightly while avoiding over-
use of the accelerator pedal. Doing so can help control excessive gasoline
consumption.
■Highway driving
Control your speed and keep at a constant speed. Before stopping at a toll
booth or similar, allow plenty of time to release the accelerator and gently
apply the brakes. A greater amount of electrical energy can be regenerated
when slowing down.
Hybrid vehicle driving tips
For economical and ecological driving, pay attention to the following points:

4176-1. Using the air conditioning system
6
Interior features
IS300h_EE(OM53D56E)
■Option control screen
The functions can be switched on and off.Cooling and dehumidification
function
Adjusting the temperature for
driver and passenger seats sepa-
rately (“DUAL” mode)
(if equipped) ( →P. 4 1 7 )
Removing pollen from the air
(Pollen removal mode)
( → P. 4 1 8 )
Press , or select “AUTO” on the air conditioning control screen.
Adjust the temperature setting.
To stop the operation, press or select “OFF” on the air conditioning
control screen.
■Automatic mode indicator
If the fan speed setting or air flow modes are operated, the automatic mode
indicator goes off. However, automatic mode for functions other than that
operated is maintained.
■Adjusting the temperature for driv er and passenger seats separately
(“DUAL” mode) (if equipped)
To turn on the “DUAL” mode, perform any of the following procedures:
●Press .
●Select “DUAL” on the option control screen.
●Adjust the passenger’s side temperature setting.
The indicator comes on when the “DUAL” mode is on.
While in “DUAL” mode, the temperature of the rear air outlets is set at the right-
hand side temperature setting.
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2
3
Using automatic mode
1
2
3

4216-1. Using the air conditioning system
6
Interior features
IS300h_EE(OM53D56E)
■Registering air conditioning settings to electronic keys (vehicles with driving position
memory)
●Unlocking the vehicle using an electronic key and turning the power switch to ON
mode will recall that key’s regist ered air conditioning settings.
●When the power switch is turned off, the cu rrent air conditioning settings will automati-
cally be registered to the electronic key that was used to unlock the vehicle.
●The system may not operate correctly if more than one electronic key is in the vicinity or
if the smart entry & start system is used to unlock a passenger door.
●The doors that can recall the air conditioni ng setting when unlocked using the smart
entry & start system can be changed.* For details, contact any authorized Lexus dealer
or repairer, or another duly qualified and equipped professional.
*: The doors that can recall the driving position memory are changed at the same time.
■Using automatic mode
Fan speed is adjusted automatically according to the temperature setting and the ambi-
ent conditions.
Therefore, the fan may stop for a while until wa rm or cool air is ready to flow immediately
after is pressed or “AUTO” is selected.
■Fogging up of the windows
The windows will easily fog up when the humidity in the vehicle is high. Turning
(“A/C”) on will dehumidify the air from the outlets and defog the windshield effectively.
●If you turn (“A/C”) off, the windows may fog up more easily.
●The windows may fog up if the recirculated air mode is used.
■Outside/recirculated air mode
●When driving on dusty roads such as tunnels or in heavy traffic, set the outside/recircu-
lated air mode button to the recirculated air mode. This is effective in preventing out-
side air from entering the vehicle interior. During cooling operation, setting the
recirculated air mode will also cool the vehicle interior effectively.
●Outside/recirculated air mode may automatically switch depending on the tempera-
ture setting or the inside temperature.
■Operation of the air conditioning system in Eco drive mode
In Eco drive mode, the air conditioning system is controlled as follows to prioritize fuel
efficiency:
●Engine speed and compressor operation controlled to restrict heating/cooling capac-
ity
●Fan speed restricted when automatic mode is selected
To improve air conditioning performance, perform the following operations:
●Adjust the fan speed
●Turn off Eco drive mode

4527-3. Do-it-yourself maintenance
IS300h_EE(OM53D56E)
CAUTION
The engine compartment contains many mechanisms and fluids that may move suddenly,
become hot, or become electrically energized. To avoid death or serious injury, observe
the following precautions.
■When working on the engine compartment
●Make sure that the “ACCESSORY” or “IGNITION ON” on the multi-information
display and the “READY” indicator are both off.
●Keep hands, clothing and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, power control unit, radiator, exhaust manifold, etc.
right after driving as they may be hot. Oil and other fluids may also be hot.
●Do not leave anything that may burn easily, such as paper and rags, in the engine
compartment.
●Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes are flamma-
ble.
●Take care because brake fluid can harm your hands or eyes and damage painted sur-
faces. If fluid gets on your hands or in your eyes, flush the affected area with clean
water immediately.
If you still experience discomfort, consult a doctor.
■When working near the electric cooling fans or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the elec tric cooling fans may automatically start to
run if the air conditioning is on and/or the coolant temperature is high. ( →P. 4 6 2 )
■Safety glasses
Wear safety glasses to prevent flying or fallin g material, fluid spray, etc. from getting in
your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine wear due to dirt
in the air.
■If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear or when
the fluid level in the accumulator is high.
If the reservoir needs frequent refilling, it may indicate a serious problem.

4557-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D56E)
■12-volt battery
→P. 4 6 3
Engine compartment
Power control unit coolant reser-
voir ( →P. 4 6 0 )
Engine oil level dipstick (→ P. 4 5 6 )
Engine coolant reservoir (→ P. 4 6 0 )
Engine oil filler cap (→ P. 4 5 7 ) Fuse box (
→P. 4 9 1 )
Wa s h e r f l u i d t a n k ( →P. 4 6 2 )
Electric cooling fans
Condenser ( →P. 4 6 2 )
Power control unit coolant
radiator ( →P. 4 6 2 )
Engine coolant radiator (→ P. 4 6 2 )1
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