2010 Lexus IS250C coolant temperature

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2
When driving
10_IS250C/350C_U
2-2. Instrument cluster
Gauges and meters
The units used on the speedometer and the tachometer gauge display may
differ depending on the model/type.

The following gauges, meters and display illuminate when the
“ENGINE START STOP” switch is in IGNITION ON mode.Speedometer
Displays the vehicle speed.
Multi-information display
→ P. 1 6 8
Tachometer
Displays the engine speed in revolutions per minute.
Tacho indicator
When the set engine speed is reached, this ring-shaped indicators comes
on in yellow. The indicator comes on in red when the engine speed
reaches a dangerous range.
Engine coolant temperature gauge
Displays the engine coolant temperature.

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4-3. Do-it-yourself maintenance
10_IS250C/350C_U
CAUTION
■When working near the electric cooling fan or radiator grille
Be sure the “ENGINE START STOP” switch is OFF.
With the “ENGINE START STOP” switch in IGNITION ON mode, the electric
cooling fan may automatically start to run if the air conditioning is on and/or the
coolant temperature is high. (→P. 400)
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from getting
in the 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.

5
When trouble arises
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5-1. Essential information
10_IS250C/350C_U
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
● Engine coolant temperature gauge needle continually points
higher than normal
■ 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 engine
■ 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, sp ongy feeling, pedal almost touches
the floor

5
When trouble arises
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5-2. Steps to take in an emergency
10_IS250C/350C_U
If your vehicle overheats
If your engine overheats:
Stop the vehicle in a safe place and turn off the automatic air
conditioning system.
Check to see if steam is coming out from under the hood.
If you see steam: Stop the engine. Carefully lift the hood after the steam sub-
sides and then restart the engine.
If you do not see steam: Leave the engine running and carefully lift the hood.
Remove the engine compartment cover. ( →P. 394)
Check to see if the cooling fan is operating.
If the fan is operating: Wait until the temperature of the engine (shown on the
instrument cluster) begins to fall and then stop the engine.
If the fan is not operating: Stop the engine immediately and call your local Lexus
dealer.
After the engine has cooled
down sufficiently, check the
engine coolant level and inspect
the radiator core (radiator) for
any leaks.STEP1
STEP2
STEP3
STEP4
STEP5

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5-2. Steps to take in an emergency
10_IS250C/350C_U
■Overheating
If you observe the following, your vehicle may be overheating.
●The engine coolant temperature gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
CAUTION
■To prevent an accident or injury when inspecting under the hood of your vehicle
●If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartment may be very hot, causing serious
injury such as burns.
●Keep hands and clothing away from the fan and other belts while the engine is
running.
●Do not loosen the radiator cap while the engine and radiator are hot.
Serious injury, such as burns, may result from hot coolant and steam released
under pressure.
Add engine coolant if required.
Water can be used in an emer-
gency measure if engine coolant
is unavailable. (→P. 5 3 1 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP6

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6-1. Specifications
10_IS250C/350C_U■
Temperature A, B, C
The temperature grades are A (the highest), B, and C, representing
the tire's resistance to the generation of heat and its ability to dissipate
heat when tested under controlled conditions on a specified indoor
laboratory test wheel.
Sustained high temperature can cause the material of the tire to degenerate
and reduce tire life, and excessive temperature can lead to sudden tire fail-
ure.
The grade C corresponds to a level of performance which all passenger car
tires must meet under the Federal Motor Vehicle Safety Standard No. 139.
Grades B and A represent higher levels of performance on the laboratory
test wheel than the minimum required by law.
Warning: The temperature grades for this tire are established for a tire that
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
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of automatic transmis-
sion, 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)
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
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

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Alphabetical index
10_IS250C/350C_U
Engine compartment cover............. 394
Engine coolantCapacity...................................................531
Checking ............................................... 398
Preparing and checking before winter .................................... 220
Engine coolant temperature gauge ....................................................... 159
Engine immobilizer system ..................93
Engine oil Capacity.................................................530
Checking ............................................... 395
Preparing and checking before winter .................................... 220
Engine oil maintenance data ............397
EPS............................................................. 204
Event data recorder.............................. 461
Floor mat.................................................. 358
Fluid Brake .......................................................400
Washer ................................................... 405
Fog lights Switch ........................................................ 176
Wattage ................................................... 541
Foot well lights....................................... 338
Front fog lights Switch ........................................................ 176
Wattage ................................................... 541 Front passenger occupant
classification system ............................. 111
Front passenger's seat belt reminder light...................................... 465
Front seats Adjustment .................................................51
Driving position memory ..................56
Seat position memory ........................60
Front turn signal lights Switch........................................................ 156
Wattage ................................................... 541
Fuel
Capacity .................................................529
Fuel gauge.............................................. 159
Fuel pump shut off system............ 460
Information ............................................542
Refueling....................................................90
Fuel door .....................................................90
Fuel filler door ...........................................90
Fuel pump shut off system.................460
Fuses .......................................................... 427
Garage door opener .......................... 362
Gauges ...................................................... 159
Glove box ................................................340
Glove box light ....................................... 341
F
G

582
10_IS250C/350C_U
What to do if...
What to do if...
A tire puncturesP. 4 8 6If you have a flat tire
The engine does not start
P. 4 9 7If the engine will not start
P. 9 3Engine immobilizer system
P. 5 0 6If the vehicle battery is discharged
The shift lever cannot be
moved outP. 4 9 9If the shift lever cannot be shifted
from P
The engine coolant temperature
gauge enters the red zone
Steam can be seen coming
from under the hood
P. 5 0 9If your vehicle overheats
The key is lostP. 5 0 0If you lose your keys
The battery runs outP. 5 0 6If the vehicle battery is discharged
The doors cannot be lockedP. 4 3Doors
The horn begins to soundP. 9 5Alarm
The vehicle is stuck in mud or
sandP. 5 1 2If the vehicle becomes stuck