overheating Lexus IS250 2012 Using the air conditioning system and defogger / LEXUS 2012 IS250,IS350 OWNERS MANUAL (OM53A87U)

138
2-1. Driving procedures
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 th e 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 stuc k 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.

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2-2. Instrument cluster
2
When driving
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 3 )

200
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.
●The vehicle rolls backward.
■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 may exceed that of normal condi-
tions
The ABS is not designed to shorten the vehicle’s stopping dist ance. 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

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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 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.

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 dr ugs 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.

514
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 in specting 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 compartm ent 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 resu lt 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 7 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP5

580
Alphabetical index
Child-protectors ...................................... 49
Cigarette lighter....................................343
CleaningExterior ................................................... 378
Interior ..................................................... 382
Seat belts................................................383
Clock ........................................................ 338
Coat hooks ..............................................355
Compass ..................................................366
Condenser ..............................................406
Console box .......................................... 330
Cooling system Engine overheating ............................513
Cornering assist sensors .................... 190
Cruise control ......................................... 186
Cup holder ..............................................332
Curtain shield airbags............................98
Customizable features .......................553
Daytime running light system ............174
Defogger* Rear window ........................................ 224
Side mirror ............................................ 224
Dimension ................................................520
Dinghy towing ................................. 211, 212
Display Satellite switch mode ....................... 339
Trip information ................................... 168
Warning message.............................. 481 Do-it-yourself maintenance ...............391
Door courtesy lights
Door courtesy lights ........................ 325
Wattage ................................................. 536
Door pockets ......................................... 334
Doors Door lock ................................33, 45, 48
Door windows ....................................... 80
Side mirrors.............................................. 77
Driver's seat belt reminder light ..... 473
Driving Correct posture.....................................96
Procedures............................................. 130
Driving position memory...................... 58
Electric power steering........................196
Electronic key If the electronic key does not operate properly............................505
Emergency, in case of If a warning message is displayed .............................................. 481
If the electronic key does not
operate properly............................505
If the engine will not start .................501
If the shift lever cannot be shifted from P................................... 503
If the vehicle has a discharged battery ...................................................510
If the warning buzzer sounds........ 471
If the warning light turns on............ 471
D
E

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Alphabetical index
If you have a flat tire ........................ 492
If you lose your keys ........................ 504
If you think something is wrong................................................... 469
If your vehicle becomes stuck ......516
If your vehicle has to be stopped in an emergency.............................. 518
If your vehicle needs to be towed ................................................... 463
If your vehicle overheats.................. 513
Emergency flashers Switch ...................................................... 462
Engine Compartment ..................................... 397
Engine switch .......................................... 141
Hood ....................................................... 394
How to start the engine...................... 141
Identification number......................... 521
If the engine will not start ................ 501
Ignition switch.......................................... 141
Overheating........................................... 513
Engine compartment cover............. 399
Engine coolant Capacity..................................................527
Checking ............................................... 404
Preparing and checking before winter .................................... 206 Engine coolant temperature
gauge....................................................... 158
Engine immobilizer system..................90
Engine oil Capacity .................................................524
Checking ................................................ 401
Preparing and checking before winter ................................... 206
EPS .............................................................. 196
Event data recorder .................................21
First-aid kit storage belt ..................... 357
Floor mat ..................................................356
Fluid Brake ....................................................... 406
Washer ...................................................... 411
Fog lights Switch.........................................................176
Wattage ................................................. 536
Footwell lights ........................................ 325
Front fog lights Switch.........................................................176
Wattage ................................................. 536
Front passenger occupant classification system .......................... 109
Front passenger's seat belt reminder light...................................... 473
F
*: For vehicles with a navigation system, refe r to the “Navigation System Owner’s Manual”.

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Alphabetical index
MaintenanceDo-it-yourself maintenance ...........391
General maintenance ..................... 387
Maintenance data..............................520
Maintenance requirements ..........385
Maintenance data................................ 386
Manual transmission............................. 152
Meter Instrument panel light control ...... 159
Meters ...................................................... 158
Micro dust and pollen filter* ............220
Mirrors Inside rear view mirror....................... 75
Side mirror heater ............................. 224
Side mirrors .............................................. 77
Vanity mirrors...................................... 337
Moon roof ...................................................83
MP3 disc* ................................................ 244
Multi-information display ....................167
Noise from under vehicle...................... 19
Odometer................................................. 158
Oil Engine oil ................................................ 401
Opener Fuel filler door......................................... 87
Hood........................................................ 394
Trunk ........................................................... 52 Outer foot lights
Outer foot lights................................. 325
Wattage ................................................. 536
Outside rear view mirrors Adjusting and folding .......................... 77
Mirror position memory ................... 58
Outside temperature display ........... 168
Overhead console ............................... 332
Overhead courtesy lights Overhead courtesy lights ............. 325
Wattage ................................................. 536
Overheating, Engine ........................... 513
Parking assist sensors*........................ 190
Parking brake.......................................... 155
Parking lights Replacing light bulbs ......................... 451
Switch .........................................................172
Wattage ................................................. 536
Personal lights Switch ....................................................... 327
Power outlet ........................................... 344
Power windows ........................................ 80
Radiator .................................................... 406
Radio* ....................................................... 229
RDS* ............................................................231
Rear sunshade ....................................... 352M
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