2010 Lexus IS250 overheating

131
2-1. Driving procedures
2
When driving
CAUTION
■When taking a nap in the vehicle
Always turn the engine off. Otherwise, you may accidentally move the shift lever or
depress the accelerator pedal, which could cause an accident or fire due to engine
overheating. Additionally, if the vehicle is parked in a poorly ventilated area, exhaust
gases may collect and enter the vehicle, leading to death or a serious health hazard.
■When braking the vehicle
●When the brakes are wet, drive more cautiously.
Braking distance increases when the brakes are wet, and may cause one side of
the vehicle to brake differently than the other side. Also the parking brake may
not securely hold the vehicle.
●If the power brake assist function does not operate, do not follow other vehicles
closely and avoid downhills or sharp turns that require braking.
In this case, braking is still possible, but it will require more force on the pedal than
usual. Braking distance may also increase.
●Do not pump the brake pedal if the engine stalls.
Each push on the brake pedal uses up the reserve for the power-assisted brakes.
●The brake system consists of 2 individual hydraulic systems: if one of the systems
fails, the other will still operate. In this case, the brake pedal should be depressed
more firmly than usual and braking distance becomes longer.
Do not drive your vehicle with only a single brake system. Have your brakes fixed
immediately.
■If the vehicle becomes stuck or bogged (AWD models)
Do not spin the wheels recklessly when any of the tires is up in the air, or stuck in
sand or mud, etc. This may damage the drive system components or propel the
vehicle forward (or in another direction) and cause an accident.

156
2-2. Instrument cluster
NOTICE
■To prevent damage to the engine and its components
●Do not let the indicator needle of the tachometer enter the red zone, which indi-
cates the maximum engine speed.
●The engine may be overheating if the temperature gauge is in the red zone (H). In
this case, immediately stop the vehicle in a safe place, and check the engine after
it has cooled completely. (P. 5 1 2 )

202
2-4. Using other driving systems
■Hill-start assist control is operational when
●The shift lever is in the D or S position.
●The brake pedal is not depressed.
■EPS operation sound
When the steering wheel operates, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.
■Reduced effectiveness of EPS
The effectiveness of EPS is reduced to prevent the system from overheating when
there is frequent steering input over an extended period of time. The steering wheel
may feel heavy as a result. Should this occur, refrain from excessive steering input or
stop the vehicle and turn the engine OFF. The system should return to normal within
10 minutes.
■If the slip indicator comes on
It may indicate a malfunction in the VSC, TRAC or hill start assist control function.
Contact your Lexus dealer.
CAUTION
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded.
●The vehicle hydroplanes while driving at high speed on the wet or slick road.
■Stopping distance when the ABS is operating will exceed that of normal condi-
tions
The ABS is not designed to shorten the vehicle’s stopping distance. Always main-
tain a safe distance from the vehicle in front of you in the following situations.
●When driving on dirt, gravel or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or roads with uneven surfaces

350
3-7. Other interior features
CAUTION
■Burns
●Use caution when seating the following persons in a seat with the seat heater on
to avoid the possibility of burns:
• Babies, small children, the elderly, the sick and the disabled
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (sleeping drugs,
cold remedies, etc.)
●Do not cover the seat with anything when using the seat heater.
Using the seat heater with a blanket or cushion increases the temperature of the
seat and may lead to overheating.
NOTICE
■To prevent seat heater damage
Do not put unevenly weighted objects on the seat and do not stick sharp objects
(needles, nails, etc.) into the seat.
■To prevent battery discharge
Turn the switches off when the engine is off.

353
3-7. Other interior features
3
Interior features
CAUTION
■Burns
●Use caution when seating the following persons in a seat with the seat heater on
to avoid the possibility of burns:
• Babies, small children, the elderly, the sick and the disabled
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (sleeping drugs,
cold remedies, etc.)
●Do not cover the seat with anything when using the seat heater.
Using the seat heater with a blanket or cushion increases the temperature of the
seat and may lead to overheating.
NOTICE
■To prevent seat heaters and ventilators damage
Do not put unevenly weighted objects on the seat and do not stick sharp objects
(needles, nails, etc.) into the seat.
■To prevent battery discharge
Turn the switches off when the engine is off.

5
When trouble arises
513
5-2. Steps to take in an emergency
■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 fans 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 if engine coolant is
unavailable. (P. 5 2 5 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP6

565
Alphabetical index
Brake
Fluid ..........................................................408
Parking brake ........................................148
Brake assist ............................................... 196
Care
Exterior ................................................... 382
Interior.....................................................385
Seat belts ............................................... 386
Cargo capacity ..................................... 206
Cargo hooks .......................................... 360
CD changer ............................................. 241
CD player.................................................. 241
Chains ......................................................... 210
Child restraint system
Booster seats, definition...................109
Booster seats, installation ..................116
Convertible seats, definition ..........109
Convertible seats, installation .........116
Front passenger occupant
classification system .......................104
Infant seats, definition ........................109
Infant seats, installation........................116
Installing CRS with LATCH
anchors ................................................... 114
Installing CRS with seat belts ..........116
Installing CRS with top straps .........119Child safety
Airbag precautions ..............................99
Battery precautions ................... 412, 511
Child restraint system ....................... 109
Child-protectors ................................... 44
How your child should wear
the seat belt ..........................................65
Installing child restraints..................... 113
Moon roof precautions...................... 82
Power window lock switch .............. 76
Power window precautions ............ 78
Removed electronic key
battery precautions .......................435
Seat belt comfort guide ..................... 63
Seat belt extender precautions...... 67
Seat belt precautions ..........................66
Seat heater precautions..... 350, 353
Trunk precautions................................. 49
Child-protectors ...................................... 44
Cigarette lighter.................................... 346
Cleaning
Exterior....................................................382
Interior .................................................... 385
Seat belts ............................................... 386
Clock .......................................................... 341
Coat hooks ............................................. 358
Compass ..................................................369
Condenser ............................................. 408
Console box ........................................... 334
Cooling system
Engine overheating............................ 512
Cornering assist sensors .................... 190
C

566
Alphabetical index
Cruise control
Cruise control ....................................... 175
Dynamic radar cruise control ....... 179
Cup holder ..............................................336
Curtain shield airbags............................ 93
Customizable features ...................... 550
Daytime running light system ........... 166
Defogger
Rear window ........................................ 228
Side mirror ............................................ 228
Dimension ................................................520
Dinghy towing ............................... 215, 216
Display
Dynamic radar cruise control ....... 179
Satellite switch mode ....................... 342
Trip information ..................................... 161
Warning message............................ 480
Do-it-yourself maintenance .............394
Door courtesy lights
Door courtesy lights......................... 329
Wattage.................................................. 534
Door pockets......................................... 338
Doors
Door lock................................ 28, 40, 43
Door windows ....................................... 76
Side mirrors ..............................................73
Driver's seat belt reminder light ..... 473
Driving
Correct posture ...................................... 91
Procedures ............................................. 124
Driving position memory ...................... 53Electric power steering........................196
Electronic key
If the electronic key does not
operate properly............................505
Emergency, in case of
If the engine will not start .................501
If the shift lever cannot be
shifted from P................................... 503
If the vehicle has a discharged
battery ................................................. 509
If the warning buzzer sounds........ 471
If the warning light turns on............ 471
If a warning message is
displayed ............................................ 480
If you have a flat tire .........................492
If you lose your keys ........................ 504
If you think something is
wrong ...................................................467
If the electronic key does not
operate properly............................505
If your vehicle becomes stuck ...... 515
If your vehicle has to be
stopped in an emergency ........... 517
If your vehicle needs to be
towed ..................................................... 461
If your vehicle overheats.................. 512
Emergency flashers
Switch ...................................................... 460
Engine
Compartment ..................................... 400
Engine switch ........................................ 134
Hood ........................................................397
How to start the engine ................... 134
Identification number ........................ 521
If the engine will not start .................501
Ignition switch ....................................... 134
Overheating .......................................... 512
D
E