2010 Lexus HS250h engine temperature

25
1-1. Hybrid system
1
Before driving
HS250h_U_75033U(Canada)
■Regenerative braking
In the following situations, kinetic energy is converted to electric energy and decel-
eration force can be obtained in conjunction with the recharging of the hybrid bat-
tery (traction battery).
●The accelerator pedal is released while driving with shift position D or B
selected.
●The brake pedal is depressed while driving with shift position D or B selected.
■Conditions in which the gasoline engine may not stop
The gasoline engine starts and stops automatically. However, it may not stop auto-
matically in the following conditions:
●During gasoline engine warm-up
●During hybrid battery (traction battery) charging
●When the temperature of the hybrid battery (traction battery) is high or low
●When the heater is switched on
*: However, when the hybrid battery (traction battery) need to becharged or while the engine is being warmed up, the gasoline
engine may not stop automatically.
■ During normal driving
The gasoline engine is predominantly used. The electric motor
(traction motor) charges the hybrid battery as necessary.
■ When accelerating sharply
The power of the hybrid battery (traction battery) is added to that of
the gasoline engine via the electric motor (traction motor).
■ When braking (regenerative braking)
The electric motor (traction motor) charges the hybrid battery
(traction battery).

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1-1. Hybrid system
HS250h_U_75033U(Canada)
■Air conditioning
Use the air conditioning only when necessary. Doing so can help control
excessive gasoline consumption.
In summer: In high temperatures, use the recirculated air mode. Doing so
will help to reduce the burden on the air conditioner and reduce fuel con-
sumption as well.
In winter: Because the gasoline engine will not automatically cut out until
the gasoline engine and the interior of the vehicle are warm, it will con-
sume fuel. Also, fuel consumption can be improved by avoiding overuse of
the heater.
■ Checking tire inflation pressure
Make sure to check the tire inflation pressure frequently. Improper tire
inflation pressure can cause poor fuel consumption.
Also, as snow tires can cause large amounts of friction, their use on dry
roads can lead to poor fuel consumption. Use a tire that is appropriate for
the season.
■Luggage
Carrying heavy luggage can lead to poor fuel consumption. Avoid carry-
ing unnecessary luggage. Installing a large roof rack can also cause poor
fuel consumption.
■Warming up before driving
Since the gasoline engine starts up and cuts out automatically when cold,
warming up the engine is unnecessary. Moreover, frequently driving short
distances will cause the engine to repeatedly warm up, which can lead to
poor fuel consumption.

141
2-1. Driving procedures
2
When driving
HS250h_U_75033U(Canada)
CAUTION
■When changing the shift position
Be careful not to change the shift position with the accelerator pedal depressed.
Changing the shift position to any positions other than P or N may cause the vehicle
to accelerate abruptly, causing an accident and resulting in death or serious injury.
■If you hear a squealing or scraping noise (brake pad wear limit indicators)
Have your Lexus dealer check and replace the brake pads as soon as possible.
Rotor damage may result if the pads are not replaced when needed.
It is dangerous to drive the vehicle when the wear limits of the brake pads and/or
those of the brake discs are exceeded.
■When the vehicle is stopped
●Do not depress the accelerator pedal unnecessarily.
If the vehicle is in any shift position other than P or N, the vehicle may accelerate
suddenly and unexpectedly, causing an accident.
●Do not leave the vehicle with the hybrid system on for a long time.
If such a situation cannot be avoided, park the vehicle in an open space and
check that exhaust fumes do not enter the vehicle interior.
●In order to prevent accidents due to the vehicle rolling away, always keep
depressing the brake pedal while the “READY” indicator is on. Apply the parking
brake as necessary.
●If the vehicle is stopped on an incline, in order to prevent accidents caused by the
vehicle rolling forward or backward, always depress the brake pedal and securely
apply the parking brake as needed.
●Avoid revving or racing the engine.
Running the engine at high speed while the vehicle is stopped may cause the
exhaust system to overheat, which could result in a fire if combustible material is
nearby.
■When the vehicle is parked
●Do not leave glasses, cigarette lighters, spray cans, or soft drink cans in the vehi-
cle when it is in the sun.
Doing so may result in the following:
• Gas may leak from a cigarette lighter or spray can, and may lead to a fire.
• The temperature inside the vehicle may cause the plastic lenses and plasticmaterial of glasses to deform or crack.

151
2-1. Driving procedures
2
When driving
HS250h_U_75033U(Canada)
■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-
information 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, driven 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
long 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 lower. ( →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 of 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.)

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2-2. Instrument cluster
HS250h_U_75033U(Canada)
■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 74 )
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
Powe r a re a
Eco Driving Indicator Light turns off

418
4-3. Do-it-yourself maintenance
HS250h_U_75033U(Canada)
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.

424
4-3. Do-it-yourself maintenance
HS250h_U_75033U(Canada)
Engine oilWith the engine at operating temperature and turned off, check the oil
level on the dipstick.
■ Checking the engine oil
Park the vehicle on level ground. After turning off the hybrid sys-
tem, wait more than 5 minutes for the oil to drain back into the
bottom of the engine.
Holding a rag under the end, pull
the dipstick out.
Wipe the dipstick clean.
Reinsert the dipstick fully.
Holding a rag under the end, pull the dipstick out and check the
oil level.
Wipe the dipstick and reinsert it fully. Low
Full

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4-3. Do-it-yourself maintenance
4
Maintenance and care
HS250h_U_75033U(Canada)Power control unit coolant reservoir
Reser voir 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 4 )
■Coolant selection
Only use “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.
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% deionized 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
caps, drain cock and water pump.
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in
the cooling systems.