2010 Lexus HS250h coolant temperature

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.)

164
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.

429
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.

5
When trouble arises
489
5-1. Essential information
HS250h_U_75033U(Canada)
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■Visible symptoms
● Fluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● High engine coolant temperature warning light flashes or comes
on
■ Audible symptoms
● Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the hybrid system
■ Operational symptoms
● Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road.
● Loss of brake effectiveness, spongy feeling, pedal almost touches
the floor

5
When trouble arises
541
5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)
If your vehicle overheats
Correction procedures■ If the engine coolant temperature warning light comes on or flashes
Stop the vehicle in a safe place and turn off the air conditioning
system.
Check to see if steam is coming out from the engine area.
If you see steam:
Stop the hybrid system. Carefully lift the hood after the steam
subsides and then restart the hybrid system.
If you do not see steam:
Leave the hybrid system operating and carefully lift the hood.
Remove the engine compartment cover. ( →P. 423)
Check to see if the cooling fans are operating.
If the fans are operating:
Wait until the high engine coolant temperature warning light goes
off and then stop the hybrid system.
If the fans are not operating:
Stop the hybrid system immediately and call your Lexus dealer.
The following may indicate that your vehicle is overheating:
● The high engine coolant temperature warning light comes on or
flashes:
The engine may be overheating.
● “HYBRID SYSTEM OVERHEAT” is shown on the multi-information
display:
The power control unit may be overheating.
Follow the correction procedure as described below.

5
When trouble arises
543
5-2. Steps to take in an emergency
HS250h_U_75033U(Canada)After the hybrid system has cooled
down, check the power control
unit coolant level and inspect the
cooling system for leaks.
Add power control unit coolant if
necessary.
Water can be used in an emer-
gency if power control unit coolant
is unavailable. (
→P. 5 5 4 )
Have the vehicle inspected at the nearest Lexus dealer as soon as possi-
ble.
■Overheating
The following symptoms may occur when your vehicle is overheating:
●The high engine coolant temperature warning light comes on or flashes, or the
hybrid system output decreases.
●Steam comes out from the engine area.
●“HYBRID SYSTEM OVERHEAT” is displayed on the multi-information display.

568
6-1. Specifications
HS250h_U_75033U(Canada)
Warning: The temperature grades of a tire assume that it is properly inflated
and not overloaded.
Excessive speed, underinflation, or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pres-
sureTire pressure when the vehicle has been parked for
three hours or more, or has not been driven more
than 1 mile or 1.5 km under that condition
Maximum inflation pres-
sureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
Recommended inflation
pressureCold tire inflation pressure recommended by a man-
ufacturer
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of transmission, power
steering, power brakes, power windows, power seats,
radio and heater, to the extent that these items are
available as factory-installed equipment (whether
installed or not)
Curb weight
The weight of a motor vehicle with standard equip-
ment, including the maximum capacity of fuel, oil and
coolant, and if so equipped, air conditioning and
additional weight optional engine
Maximum loaded vehicle
weight
The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options weight
Normal occupant weight150 lb. (68 kg) times the number of occupants speci-
fied in the second column of Table 1
* that follows