overheating Lexus GS300h 2017 Owner's Manual

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)

2064-1. Before driving
GS450h_300h_OM_OM30F92E_(EE)
WARNING
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, if you accidentally move the shift lever or
depress the accelerator pedal, this could cause an accident or fire due to hybrid system
overheating. Additionally, if the vehicle is parked in a poorly ventilated area, exhaust
gases may collect and enter the vehicle, lead ing to death or a serious health hazard.
■When braking
●When the brakes are wet, drive more cautiously.
Braking distance increases when the brakes are wet, and this 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 electronically controlled brake system does not operate, do not follow other
vehicles closely and avoid hills or sharp turns that require braking.
In this case, braking is still possible, but the brake pedal should be depressed more
firmly than usual. Also, the braking distance will increase. Have your brakes fixed
immediately.
●The brake system consists of 2 or more indi vidual hydraulic systems; if one of the sys-
tems fails, the other(s) will still operate. In this case, the brake pedal should be
depressed more firmly than usual and the braking distance will increase. Have your
brakes fixed immediately.
■If the vehicle becomes stuck
Do not spin the wheels excessively when any of the tires is up in the air, or the vehicle is
stuck in sand, mud, etc. This may damage the driveline components or propel the vehi-
cle forward or backward, causing an accident.

215
4-1. Before driving
4
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.

2204-2. Driving procedures
GS450h_300h_OM_OM30F92E_(EE)
■When the steering lock cannot be released
■Steering lock motor overheating prevention
To prevent the steering lock motor from overheating, the motor may be suspended if the
hybrid system is turned on and off repeatedly in a short period of time. In this case, refrain
from operating the hybrid system. After abou t 10 seconds, the steering lock motor will
resume functioning.
■When “Check Entry & Start System” will be displayed on the multi-information display
The system may be malfunctioning. Have the vehicle inspected by any authorized Lexus
retailer or Lexus authorized repairer, or any reliable repairer immediately.
■If the “READY” indicator does not come on
In the event that the “READY” indicator does not come on even after performing the
proper procedures for starting the vehicle, contact any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
■If the hybrid system is malfunctioning
 P. 466
■If the electronic key battery is depleted P. 435
■Operation of the power switch
●If the switch is not pressed shortly and firmly, the power switch mode may not change or
the hybrid system may not start.
●If attempting to restart the hybrid system immediately after turning the power switch off,
the hybrid system may not start in some cases. After turning the power switch off,
please wait a few seconds before restarting the hybrid system.
■If the smart entry & start system has be en deactivated in a customized setting
 P. 527
“Steering Lock active” will be displayed on the
multi-information display.
Check that the shift lever is set in P. Press the
power switch while turning the steering wheel
left and right.

233
4-2. Driving procedures
4
Driving
GS450h_300h_OM_OM30F92E_(EE)
■Parking brake operation
●When the power switch is not in ON mode, the parking brake cannot be released using
the parking brake switch.
●When the power switch is not in ON mode, automatic mode (automatic brake setting
and releasing) is not available.
●If the parking brake is operated repeatedly over a short period of time, the system may
restrict operation to prevent overheating. If this happens, refrain from operating the
parking brake. Normal operation wi ll return after about 1 minute.
●Vehicles with towing package: In situations such as when parking while towing a trailer,
the maximum amount of braking force can be used by pressing the parking brake
switch with the parking brake already set.
●Vehicles without towing package: In situations such as when parking on a steep slope *,
the maximum amount of braking force can be used by pressing the parking brake
switch with the parking brake already set.
* : Use wheel chocks when parking on a steep slope.
■Parking brake operation sound
When the parking brake operates, a motor sound (whirring sound) may be heard. This
does not indicate a malfunction.
■Parking brake indicator light
●Depending on the power switch mode, the parking brake indicator light will come on
and stay on as described below:
ON mode: Comes on until the parking brake is released.
Not in ON mode: Stays on for approximately 15 seconds.
●When the power switch is turned off with th e parking brake set, the parking brake indi-
cator light will stay on for about 15 seco nds. This does not indicate a malfunction.
■When there is a malfunction in the system
Warning lights and/or warning message will turn on or flash. ( P. 462, 466)
Depending on the condition, the park ing brake indicator light may flash.
■Parking the vehicle P. 200
■Parking brake engaged warning buzzer P. 472
■Usage in winter time P. 334

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

535
7
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
1
2
3
1
2

584Alphabetical index
GS450h_300h_OM_OM30F92E_(EE) Cargo hooks........................................... 374 CD player
*
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

586Alphabetical index
GS450h_300h_OM_OM30F92E_(EE) Dynamic radar cruise control
with full-speed range ....................... 296
Function .................................................. 296
Warning message.............................466
Dynamic Rear Steering (DRS)........ 325 Function .................................................. 325
Warning message.............................466
DVD player *
Eco drive mode ........................................ 311
Electric motor (traction motor) ......... 76
Electric Power Steering (EPS)........ 325 Function .................................................. 325
Warning light .........................................461
Warning message.............................466
Electronic key.......................................... 134 Battery-saving function.................... 155
If the electronic key does not operate properly ............................ 527
Replacing the battery.......................435
Emergency, in case of
If a warning buzzer sounds ......... 460
If a warning light turns on.............. 460
If a warning message is displayed ............................................466
If the 12-volt battery is discharged........................................ 530
If the electronic key does not operate properly ............................ 527
If the hybrid system will not start ........................................................ 523
If the parking brake cannot be released........................................525
If you have a flat tire .............498, 509 If you think something
is wrong .............................................. 459
If your vehicle becomes stuck ..................................................... 542
If your vehicle has to be stopped in an emergency ......... 453
If your vehicle needs to be towed ............................................ 454
If your vehicle overheats................ 535
Emergency brake signal.................... 325
Emergency flashers............................. 452
Emergency tire puncture
repair kit ................................................ 509
Energy monitor ....................................... 126
Engine ....................................................... 548 Accessory mode ................................. 218
Compartment ..................................... 403
Engine switch ........................................ 217
Hood ......................................................... 401
How to start the hybrid
system.................................................... 217
Identification number....................... 548
Ignition switch (power switch) .................................. 217
Overheating ........................................ 535
Power switch ......................................... 217
Engine compartment cover ............. 405
Engine coolant....................................... 409 Capacity................................................. 552
Checking ............................................... 409
Preparing and checking before winter.................................... 334
E