engine overheat LEXUS GS300H 2019 Owners 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

15Pictorial 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. 405Engine 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
*2: 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 numberappearing 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 tachometerenter the red zone, which indicates the maximum engine speed.
●The engine may be overheating if the engine coolant temperature gauge is in the redzone (H). In this case, immediately stop the vehicle in a safe place, and check theengine after it has cooled completely. ( P. 535)

2034-1. 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 starting the vehicle
Always keep your foot on the brake pedal while stopped with the “READY” indicator is illuminated. This prevents the vehicle from creeping.
■When driving the vehicle
●Do not drive if you are unfamiliar with the location of the brake and accelerator ped-als to avoid depressing the wrong pedal.
• Accidentally depressing the accelerator pedal instead of the brake pedal will
result in sudden acceleration that may lead to an accident. • When backing up, you may twist your body around, leading to a difficulty in oper-ating the pedals. Make sure to operate the pedals properly.
• Make sure to keep a correct driving posture even when moving the vehicle only slightly. This allows you to depress the brake and accelerator pedals properly.• Depress the brake pedal using your right foot. Depressing the brake pedal using
your left foot may delay response in an emergency, resulting in an accident.
●The driver should pay extra attention to pedestrians when the vehicle is powered only
by the electric motor (traction motor). As there is no engine noise, the pedestrians may misjudge the vehicle’s movement.
●Do not drive the vehicle over or stop the vehicle near flammable materials.
The exhaust system and exhaust gases can be extremely hot. These hot parts may cause a fire if there is any flammable material nearby.
●During normal driving, do not turn off the hybrid system. Turning the hybrid system off
while driving will not cause loss of steering or braking control, however, power assist to the steering will be lost. This will make it more difficult to steer smoothly, so youshould pull over and stop the vehicle as soon as it is safe to do so.
In the event of an emergency, such as if it becomes impossible to stop the vehicle in the normal way: P. 453
●Use engine braking (downshift) to maintain a safe speed when driving down a steep
hill. Using the brakes continuously may cause th e brakes to overheat and lose effective- ness. ( P. 224)
●Do not adjust the positions of the steering wheel, the seat, or the inside or outside rear view mirrors while driving.Doing so may result in a loss of vehicle control.
●Always check that all passengers’ arms, heads or other parts of their body are notoutside the vehicle.

2054-1. 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 suddenlyand unexpectedly, causing an accident.
●In order to prevent accidents due to the vehicle rolling away, always keep depressingthe brake pedal while stopped with the “READY” indicator is illuminated, and applythe parking brake as necessary.
●If the vehicle is stopped on an incline, in order to prevent accidents caused by thevehicle 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 exhaustsystem 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:
• Gas may leak from a cigarette lighter or spray can, and may lead to a fire. • The temperature inside the vehicle may cause the plastic lenses and plastic mate-
rial of glasses to deform or crack. • Soft drink cans may fracture, causing the contents to spray over the interior of thevehicle, and may also cause a short circuit in the vehicle’s electrical components.
●Do not leave cigarette lighters in the vehicle. If a cigarette lighter is in a place such asthe glove box or on the floor, it may be lit accidentally when luggage is loaded or the
seat is adjusted, causing a fire.
●Do not attach adhesive discs to the windshield or windows. Do not place containers such as air fresheners on the instrument panel or dashboard. Adhesive discs or con-
tainers may act as lenses, causing a fire in the vehicle.
●Do not leave a door or window open if the curved glass is coated with a metallized film such as a silver-colored one. Reflecte d sunlight may cause the glass to act as a
lens, causing a fire.
●Always apply the parking brake, shift the shift lever to P, stop the hybrid system and lock the vehicle.
Do not leave the vehicle unattended while the “READY” indicator is illuminated. If the vehicle is parked with the shift lever in P but the parking brake is not set, thevehicle may start to move, possibly leading to an accident.
●Do not touch the exhaust pipes while the “READY” indicator is illuminated or imme-diately after turning the hybrid system off.Doing so may cause burns.

2154-1. 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 changes.
■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 steeringwheel 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 onA 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: • The AHS (Adaptive High-beam System) (ifequipped);
• The Automatic High Beam (if equipped); • The AFS (Adaptive Front-lighting System) (ifequipped); or
• The LED headlight system A buzzer also sounds. Have the vehicle inspected by any authorized Lexus
retailer or Lexus authorized repairer, or any reliable repairer.
(If equipped)
Indicates a malfunction in the RSA (Road Sign Assist)
A buzzer also sounds  Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer.
Warning messageDetails/Actions

535
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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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