cooling Lexus HS250h 2010 Operating the lights and windshield wipers / LEXUS 2010 HS250H OWNERS MANUAL (OM75006U)

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1-1. Hybrid system
■Charging the battery
As the gasoline engine charges the hybrid battery (traction battery), the battery
does not need to be charged from an outside source. However, if the vehicle is left
parked for a long time the hybrid battery will slowly discharge. For this reason, be
sure to drive the vehicle at least once every few months for at least 30 minutes or
10 miles (16 km). If the hybrid battery be comes fully discharged and you are unable
to jump-start the vehicle with the 12-v olt battery, contact your Lexus dealer.
■After the 12-volt battery has discharged or has been changed or removed
The gasoline engine may not stop even if the vehicle is running on the hybrid battery
(traction battery). If this continues for a few days, contact your Lexus dealer.
■Sounds and vibrations specific to a hybrid vehicle
There may be no engine sounds or vibrat ion even though the vehicle is able to
move. Always change the shift position to P when parked.
The following sounds or vibrations may occur 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 ba ttery (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 transaxle wh en the hybrid system starts or stops,
or while the vehicle is idling.
●Engine sounds may be heard when accelerating sharply.
●Sounds may be heard due to regenerati ve braking when the brake pedal is
depressed and accelerator is loosened.
●Other sounds, such as motors and mechanical noises, may be heard from the
brake system 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 vent on the side of rear left
seatback.
When driving in Eco mode, the fan noise may be louder than when driving nor-
mally.
■Maintenance, repair, recycling, and disposal
Contact your Lexus dealer regarding main tenance, repair, recycling and disposal.
Do not dispose of the vehicle yourself.

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1-1. Hybrid system
Hybrid battery air vent
There is an air intake vent on the
side of the rear left seatback for
the purpose of cooling the hybrid
battery (traction battery). If the
vent 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, yo ur 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 improper operation is attempted.
If a warning message is shown on
the multi-information display
, read
the message and follow the
instructions.
( P. 501 )

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3-1. Using the air conditioning system and defogger
Automatic air conditioning system
Air outlets and fan speed are automati cally adjusted according to the tem-
perature setting.
Vehicles with a navigation system
Owners of models equi pped with a na
vigation system should refer to
the “Navigation System Owner’s Manual”.
Vehicles without a navigation system
Automatic
mode button
Driver’s side 
temperature display
Dual
mode
button
Fan speed control buttons Air outlet display
Fan speed display
Passenger’s side 
temperature display
Driver’s side
temperature 
control buttons
Outside/recirculated air
mode buttonWindshield
defogger button Passenger’s side

temperature 
control buttons
Micro dust 
and pollen 
filter mode 
button
“OFF” button Air outlet selector button
Cooling and 
dehumidification 
function on/off 
button

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3-1. Using the air conditioning system and defogger
■Using the system in recirculated air mode
The windows will fog up more easily if recirculated air mode is used.
■Window defogger feature
Recirculated air mode may automatically switch to (outside air) mode in sit-
uations where the windows need to be defogged.
■When micro dust and pollen filter is active
●In order to prevent the windshield from fogging up when the outside air is cold,
the following may occur:
• Outside air mode does not switch to (recirculated air) mode.
• The air conditioning syst em operates automatically.
• The operation cancels after 1 minute.
●In rainy weather, the windows may fog up. Press .
■When outside air temperature is below 32 F (0C)
The cooling and dehumidification func tion may not operate even when
is
pressed.
■Air conditioning odors
●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 oper ation in extremely humid weather. The dif-
ference between the temperature of the outs ide air and that of the windshield can
cause the outer surface of the windshield to fog up, blocking your vision.

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4-3. Do-it-yourself maintenance
CAUTION
The engine compartment contains many mechanisms and fluids that may move sud-
denly, 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 indicator on the “POWER” switch and the “READY” indicator
are both off.
●Keep hands, clothing and tools away from the moving fans 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 flam-
mable.
■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 electric cooling fans may automati-
cally start to run if the air conditioning is on and/or the coolant temperature is high. 
(  P. 4 3 0 )
■Safety glasses
Wear safety glasses to prevent flying or falling 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. Also, a backfire could cause a fire in the engine compartment.

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4-3. Do-it-yourself maintenance
Engine compartment
Engine coolant reservoir 
( P. 4 2 8 )
Engine oil filler cap 
( P. 425)
Engine oil level dipstick 
( P. 4 2 4 )
Power control unit coolant
reservoir ( P. 4 2 8 )
Brake fluid reservoir  (P. 4 3 1 )Fuse box ( P. 455)
Engine coolant radiator 
( P. 430)
Power control unit coolant
radiator ( P. 430)
Condenser ( P. 430)
Electric cooling fans
Washer fluid tank 
( P. 4 3 2 )

430
4-3. Do-it-yourself maintenance
Radiator and condenser
Check the radiator and condenser and clear away any foreign objects. 
If either of the above parts is extremely dir
ty or you are not sure of their
condition, have your vehicle inspected by your Lexus dealer.
CAUTION
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps. 
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing burns or other injuries.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water
and antifreeze must be used to provide proper lubrication, corrosion protection
and cooling. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
CAUTION
■When the hybrid system is hot
Do not touch the radiators or condense r as they may be hot and cause burns.

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4-3. Do-it-yourself maintenance
Fuse layout and amperage ratings
Engine compartment
FuseAmpereCircuit
1HTR50 AAir conditioning system
2RDI40 AElectric cooling fans
3OIL PMP10 AHybrid system, transmission
4S-HORN10 ANo circuit
5ABS MAIN NO.27. 5 AElectronically controlled brake system
6H-LP CLN30 AHeadlight cleaner
7AMP NO.130 AAudio system, back door opener
8IGCT30 APCU, IGCT NO.2, IGCT NO.3,
hybrid system
9P CON MAIN7. 5 A
P position control system, hybrid sys-
tem, smart access system with push-
button start

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4-3. Do-it-yourself maintenance
4
Maintenance and care
35SPARE30 ASpare fuse
36SPARE10 ASpare fuse
37SPARE7. 5 ASpare fuse
38EFI MAIN20 AEFI NO.2, fuel system
39BATT FAN10 ABattery cooling fan
40IG220 A
Hybrid system, multiport fuel injec-
tion system/sequential multiport fuel
injection system, MET, IGN
FuseAmpereCircuit

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5-2. Steps to take in an emergency
NOTICE
■Exclusive jump starting terminal precaution
The exclusive jump starting terminal is to be used when charging the 12-volt battery
from another vehicle in an emergency. It ca nnot be used to jump start another vehi-
cle.
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in
the cooling fans or belt.