coolant Lexus HS250h 2010 Do-it-yourself maintenance / LEXUS 2010 HS250H OWNERS MANUAL (OM75006U)

151
2-1. Driving procedures
2
When driving
■Situations in which EV drive mode cannot be turned on
It may not be possible to turn EV drive mode on in the following situations. If it can -
not be turned on, a buzzer will sound and a message will be shown on the multi-
info
rmation display.
●Engine coolant temperature is low.
●Vehicle speed is about 19mph (30km/h) or more.
●The hybrid battery (traction battery) is low. 
An “Energy Monitor” display of level 3 or lower may indicate a low battery level.
(  P. 3 2 )
● The temperature of the hybrid system is high. 
The vehicle has been left in the sun, driv en on a
hill, driven at high speeds, etc.
●The temperature of the hybrid system is low. 
The vehicle has been left in temperatures lower than about 32°F (0°C) for a
l
ong period of time etc.
●The gasoline engine is warming up.
●The accelerator pedal is depressed firmly or the vehicle is on a hill etc.
●The windshield defogger is in use.
■Automatic cancellation of EV drive mode
When driving in EV drive mode, the gasoline engine may automatically restart in
the
following situations. When EV drive mo de is canceled, a buzzer will sound and
the EV drive mode indicator will flash and go off.
●The hybrid battery (traction battery) becomes low. 
The remaining battery level indicated in the “Energy Monitor” display is level 2
or lo
wer. ( P. 3 2)
●Vehicle speed becomes more than about 19 mph (30 km/h).
●The accelerator pedal is depressed firmly or the vehicle is on a hill etc.
When it is possible to inform the driver o
f automatic cancellation in advance, a prior
notice screen will appear on the multi-information display.
■ Possible driving distance when driving in EV drive mode
In EV drive mode, it is possible to drive up to about several hundred yards if driving
at
a speed of about 19 mph (30 km/h) or less. (The distance that is possible
depends on the hybrid battery [traction battery] level and driving conditions.)

164
2-2. Instrument cluster
■Limitations of brightness adjustment
The brightness of the instrument panel lights is automatically adjusted based on the
light sensor detecting how bright the surroundings are. However, if the instrument
panel brightness has been manually set to either the brightest or dimmest setting,
the automatic adjustment will not be performed.
■Hybrid System Indicator
●By keeping the indicator needle within Eco area, environmentally-friendly driv-
ing can be achieved.
Hybrid Eco area shows that gasoline engine power is not being used very often.*
1
●Charge area indicates regeneration*2 status. Regenerated energy will be used
to charge the hybrid battery.
*
1: The gasoline engine will automatically stop and restart under various condi- tions.
*
2: When used in this manual, “regeneration” refers to the conversion of energy created by the movement of the vehicle into electrical energy.
■Customization
Settings (e.g. Sensitivity of the ambient light sensor used for dimming the meter
lights) can be changed. (Customizable features P. 5 7 2 )
NOTICE
■To prevent damage to the hybrid system and its components
A high engine coolant temperature warning light ( P. 492) is installed instead of
an engine coolant temperature gauge. If the high engine coolant temperature
warning light illuminates or flashes, the vehicle may be overheating. Immediately
stop the vehicle in a safe area ( P. 5 4 1 ) .
Eco area 
Eco Driving Indicator Light comes on
Hybrid Eco area 
Eco Driving Indicator Light comes on
Charge area 
Eco Driving Indicator Light comes on
Po w e r a r e a 
Eco Driving Indicator Light turns off

244
2-5. Driving information
Winter driving tips
Carry out the necessary preparations and inspections before driving the
vehicle in winter. Always drive the vehicle in a manner appropriate to the
prevailing weather conditions.
■ Pre-winter preparations
●Use fluids that ar
e appropriate to the prevailing outside tempera -
tures.
• Engine oil
• Engine/power control unit coolant
• Washer fluid
● Ha
ve the vehicle fitted with four snow tires or purchase a set of
tire chains for the front tires.
Ensure that all tires are the same si ze and brand, and that chains match
the size of the tires.
■ Before driving the vehicle
Perform the following accord ing to the driving conditions:
● D
o not try to forcibly open a w indow or move a wiper that is fro-
zen. Pour warm water over the frozen ar
ea to melt the ice. Wipe
away the water immediately to prevent it from freezing.
● T
o ensure proper operation of the climate control system fan,
remove any snow that has accumulated on the air inlet vents in
front of the windshield.
● R
emove any ice that has accumul ated on the vehicle chassis.
● P
eriodically check for and remove any excess ice or snow that
may have accumulated in the wheel well or on the brakes.
■ When driving the v
ehicle
Accelerate the vehicle slowly and drive at a reduced speed suitable to the
road conditions.

411
4-2. Maintenance
4
Maintenance and care
General maintenance
Engine compartment
Tr u n k
ItemsCheck points
Brake fluidIs the brake fluid at the correct level?
( P. 4 3 1 )
CoolantIs the engine coolant at the correct
level? ( P. 4 2 8 )
Engine oilIs the engine oil at the correct level? 
( P. 4 2 4 )
Exhaust systemThere should not be any fumes or
strange sounds.
Radiator/condenser
The radiator and condenser should
be free from foreign objects. 
( P. 4 3 0 )
Wa s h e r f l u i dIs there sufficient washer fluid? 
( P. 4 3 2 )
ItemsCheck points
12-volt batteryCheck the connections. ( P. 4 3 3 )
Listed below are the general maintenance items that should be performed
at the intervals specified in the “Warranty and Service Guide” or “Owner’s
Manual Supplement”. It is recommend ed that any problem you notice
should be brought to the attention of your Lexus dealer or qualified service
shop for advice.

416
4-3. Do-it-yourself maintenance
Do-it-yourself service precautions
If you perform maintenance by yourself, be sure to follow the correct pro-
cedure as given in these sections.
ItemsPa r t s a n d t o o l s
12-volt battery condition ( P. 4 3 3 )
•Grease
• Conventional wrench 
(for terminal clamp bolts)
Brake fluid level ( P. 4 3 1 )
• FMVSS No.116 DOT 3 or SAE
J1703 brake fluid
•Rag or paper towel
• Funnel (used only for adding brake
fluid)
Engine/power control unit coolant
level ( P. 4 2 8 )
• “Toyota Super Long Life Coolant”
or a similar high quality ethylene
glycol based non-silicate, non-
amine, non-nitrite and non-borate
coolant with long-life hybrid
organic acid technology.
For the U.S.A.: 
“Toyota Super Long Life Coolant”
is pre-mixed with 50% coolant and
50% deionized water.
For Canada: 
“Toyota Super Long Life Coolant”
is pre-mixed with 55% coolant and
45% deionized water.
• Funnel (used only for adding cool- ant)

418
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.

422
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 )

428
4-3. Do-it-yourself maintenance
Coolant
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the hybrid system is cold.
Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. (P. 5 5 2 )

429
4-3. Do-it-yourself maintenance
4
Maintenance and care
Power control unit coolant reservoirReservoir cap
“FULL” line
“LOW” line
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line. (P. 5 5 2 )
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a s
imilar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.: “Toyota Super Long Life Coolant” is a
mixture of 50% coolant and 50%
deionized water. (Minimum temperature: -31 F [-35C])
Canada: “Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% d
eionized water. (Minimum temperature: -44 F [-42 C])
For more details about coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiators, hoses, engine/power control unit coolant reservoir
ca
ps, drain cock and water pump. 
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in
the coo
ling systems.

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.