engine overheat Lexus GS300h 2017 Owner's Manual

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GS450h_300h_OM_OM30F92E_(EE) 6-3. Do-it-yourself maintenance
Do-it-yourself service precautions ................................399
Hood ................................................ 401
Positioning a floor jack.............402
Engine compartment............... 403
12-volt battery............................... 412
Tires .................................................. 416
Tire inflation pressure...............429
Wheels............................................. 431
Air conditioning filter................433
Electronic key battery ..............435
Checking and replacing fuses .............................................. 437
Light bulbs ..................................... 442
7-1. Essential information Emergency flashers...................452
If your vehicle has to be stopped in an
emergency.................................453 7-2. Steps to take in an
emergency
If your vehicle needs to be towed ................................454
If you think something is wrong .......................................459
If a warning light turns on or a warning buzzer
sounds..........................................460
If a warning message is displayed................................. 466
If you have a flat tire (vehicles with spare tire) ..... 498
If you have a flat tire (vehicles without spare
tire) ............................................... 509
If the hybrid system will not start................................523
If the parking brake cannot be released.................525
If the electronic key does not operate properly ............. 527
If the 12-volt battery is discharged ................................ 530
If your vehicle overheats .........535
If the vehicle becomes stuck.............................................. 542
7When trouble arises

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Pictorial index
GS450h_300h_OM_OM30F92E_(EE) Windshield wipers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 251
Precautions against winter season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 334
To prevent freezing (windshield wiper de-icer)
*1
. . . . . . . . . . . . . . . . . . . . . . P. 352
Precautions against car wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 392
Fuel filler door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P . 257
Refueling method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 257
Fuel type/fuel tank capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 549
Tires. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 416
Tire size/inflation pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 555
Winter tires/tire chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 33 4
Checking/rotation/tire pressure warning system *1
. . . . . . . . . . . . . . . . . . . . . P. 416
Coping with flat tires. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 498, 509
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 401
Opening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 401
Engine compartment cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 405
Engine oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 550
Coping with overheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 535
Warning messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 468
Headlights/front position lights/daytime running lights . . . . . . . . . . . P. 237
Front turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 231
Front fog lights/rear fog light *2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 250
Side turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 231
Tail lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 237
Stop lights
Emergency brake signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 325
Rear turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 231
Back-up light *2
Shifting the shift lever to R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 224
License plate lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 237
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Light bulbs of the exterior lights for driving
(Replacing method: P. 442, Watts: P. 558)
*1
: If equipped
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: They may be located on the opposite side depending on the target region.
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1102. Instrument cluster
GS450h_300h_OM_OM30F92E_(EE)
WARNING
■The information display at low temperatures
Allow the interior of the vehicle to warm up before using the liquid crystal information
display. At extremely low temperatures, the information display monitor may respond
slowly, and display changes may be delayed.
For example, there is a lag between the driver’s shifting and the new gear number
appearing on the display. This lag could cau se the driver to downshift again, causing
rapid and excessive engine braking and po ssibly an accident resulting in death or
injury.
NOTICE
■To prevent damage to the hybrid system and its components
●While the tachometer is displayed, do not let the indicator needle of the tachometer
enter the red zone, which indicates the maximum engine speed.
●The engine may be overheating if the engine coolant 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. 535)

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4-1. Before driving
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Driving
GS450h_300h_OM_OM30F92E_(EE)
WARNING
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When the vehicle is stopped
●Do not depress the accelerator pedal unnecessarily.
If the shift lever is any position other than P or N, the vehicle may accelerate suddenly
and unexpectedly, causing an accident.
●In order to prevent accidents due to the vehicle rolling away, always keep depressing
the brake pedal while stopped with the “READY” indicator is illuminated, and 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, alwa ys 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 vehicle
when it is in the sun.
Doing so may result in the following:

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4-1. Before driving
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Driving
GS450h_300h_OM_OM30F92E_(EE)
■Passing other vehicles
Consider the total combined length of your vehicle and trailer and ensure that
the vehicle-to-vehicle distance is sufficient before executing lane change s.
■Transmission information
To maintain engine braking efficiency, when using engine braking, when driv-
ing on a long steep downgrade, do not use the transmission in D. (P. 227)
■If the engine overheats
Towing a loaded trailer up a long, steep incline in temperatures exceeding 30 C (85 F) may result in the engine overheating. If the engine coolant tem-
perature gauge indicates that the engine is overheating, turn the air condition-
ing off immediately, leave the road and stop the vehicle in a safe place. (  P. 535)
■When parking the vehicle
Always place wheel chocks under the wheels of both the vehicle and trailer.
Firmly set the parking brake and shift the shift lever to P.
WARNING
Follow all the instructions described in this se ction. Failure to do so could cause an acci-
dent resulting in death or serious injury.
■Trailer towing precautions
When towing, make sure that none of the weight limits are exceeded. ( P. 211)
■To avoid accident or injury
●Do not tow a trailer when the compact spare tire is installed on your vehicle.
●Do not tow a trailer when the tire installed is repaired with the emergency tire punc-
ture repair kit.
●Do not use cruise control (if equipped) or dynamic radar cruise control with full-
speed range (if equipped) when trailer towing.
■Vehicle speed in towing
Observe the legal maximum speeds for trailer towing.
■Before descending hills or long declines
Reduce speed and downshift. However, never downshift suddenly while descending
steep or long downhill grades.
■Operation of the brake pedal
Do not hold the brake pedal depressed often or for long periods of time.
Doing so may result in the brake ov erheating or reduce braking effects.

3284-5. Using the driving support systems
GS450h_300h_OM_OM30F92E_(EE)
■Sounds and vibrations caused by the ABS, brake assist, VSC, Hill-start assist control,
TRC and VGRS systems
Any of the following conditions may occur when the above systems are operating. None
of these indicates that a malfunction has occurred.
●Vibrations may be felt through the vehicle body and steering.
●A motor sound may be heard after the vehicle comes to a stop.
■ECB operation sound
ECB operating sound may be heard in the follow ing cases, but it does not indicate that a
malfunction has occurred.
●Operating sound heard from the engine compartment when the brake pedal is oper-
ated.
●Motor sounds of the brake system heard from the front part of the vehicle when the
driver’s door is opened.
●Operating sound heard from the engine compartment when one or two minutes
passed after the stop of the hybrid system.
■EPS, VGRS and DRS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction.
■Automatic reactivation of TRC and VSC systems
After turning the TRC and VSC systems off, the systems will be automatically re-enabled
in the following situations:
●When the power switch is turned off
●If only the TRC system is turned off, the TR C will turn on when vehicle speed increases
If both TRC and VSC systems are turned off, automatic re-enabling will not occur when
vehicle speed increases.
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system 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 hybrid system off. The EPS system should return to nor-
mal within 10 minutes.
■Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate;
●The shift lever is in a position other than N or P (when starting off forward/backward on
an upward incline).
●The vehicle is stopped.
●The accelerator pedal is not depressed.
●The parking brake is not engaged.

4747-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
(If equipped)
Indicates that steering control function is temporarily
canceled due to the LKA (L ane-Keeping Assist) system
determining that the driver does not have their hands on
the steering wheel while the steering control function is on A buzzer also sounds.
 Firmly hold the steering wheel.
Indicates that the parking brake system is overheating
A buzzer also sounds.
 Do not use the parking brake until the message dis-
appears.
Indicates an engine malfunction
A buzzer also sounds.
 Have the vehicle inspected by any authorized Lexus
retailer or Lexus authorized repairer, or any reliable
repairer.
Indicates an engine malfunction
A buzzer also sounds.
 Have the vehicle inspected by any authorized Lexus
retailer or Lexus authorized repairer, or any reliable
repairer.
Warning messageDetails/Actions

4847-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
Indicates that engine oil level is low
This message may appear if the vehicle is stopped on a
slope. Move the vehicle to a level surface and check to
see if the message disappears.
A buzzer also sounds.
 Check the level of engine oil, and add if necessary.
Indicates that the hybrid system has overheated
This message may be displayed when driving under
severe operating conditions. (For example, when driv-
ing up a long steep hill.)
A buzzer also sounds.
 Stop and check. ( P. 535)
Indicates a malfunction in:

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7-2. Steps to take in an emergency
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
If your vehicle overheats
●The needle of the engine coolant temperature gauge ( P. 104) enters the
red zone or a loss of hybrid system power is experienced. (For example, the
vehicle speed does not increase.)
● “Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” or
“Hybrid System Overheated Reduced Output Power” ( P. 466) is shown on
the multi-information display.
● Steam comes out from under the hood.
■If the needle of the engine coolant temperature gauge enters the red zone
or “Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display
Stop the vehicle in a safe place and turn off the air conditioning system, and
then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has cooled down sufficiently, inspect the hoses and
cooling system for leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact any autho-
rized Lexus retailer or Lexus
authorized repairer, or any reli-
able repairer.
The following may indicate that your vehicle is overheating.
Correction procedures
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3
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2

584Alphabetical index
GS450h_300h_OM_OM30F92E_(EE) Cargo hooks........................................... 374 CD player
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Chains ....................................................... 336
Child restraint system ............................ 57 Baby seats, definition ..........................58
Baby seats, installation ....................... 67
Child seats, definition..........................58
Child seats, installation....................... 67
Installing CRS with ISOFIX rigid anchors........................................ 70
Installing CRS with seat belts.......... 67
Installing CRS with top strap ............ 71
Junior seats, definition ........................58
Junior seats, installation ..................... 69
Child safety................................................. 56 12-volt battery
precautions............................. 414, 534
Airbag precautions .............................. 45
Child restraint system......................... 57
How your child should
wear the seat belt ..................... 39, 40
Installing child restraints .................... 66
Moon roof precautions ................... 198
Power window lock switch.............193
Power window precautions .......... 195
Rear door child-protectors ............143
Removed electronic key battery precautions ....................... 436
Seat belt comfort guide ..................... 39
Seat belt precautions .......................... 42
Seat heater precautions ...................361
Trunk precautions ..............................149
Child-protectors ................................... 143 Cleaning....................................... 390, 394
Aluminum wheels................................ 391
Exterior ................................................... 390
Interior..................................................... 394
Seat belts ............................................... 395
Clock ............................................... 105, 378
Coat hooks.............................................. 382
Condenser ................................................ 411
Console box ........................................... 370
Console box light ................................... 371
Coolant..................................................... 409 Capacity................................................. 552
Checking ............................................... 409
Preparing and checking
before winter.................................... 334
Cooling system ..................................... 409
Engine overheating .......................... 535
Hybrid system overheating.......... 535
Consumption screen ........................... 126
Cruise control Cruise control .....................................308
Dynamic radar cruise control with full-speed range ................... 296
Cup holders .............................................. 371
Curtain shield airbags .......................... 43
Customizable features.........................561