2018 Lexus GS300 overheating

GS350_300_GS F_OM_OM30G34U_(U)
912. Instrument cluster
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 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. 509)

GS350_300_GS F_OM_OM30G34U_(U)
992. Instrument cluster
2
Instrument cluster
NOTICE
■To prevent damage to the engine and its components
●Do not let the indicator of the tachometer enter the red zone, as it represents the
engine speed range which exceeds the maximum safe engine speed.
●In the following situations, th e engine may be overheating. In this case, immediately
stop the vehicle in a safe place, and check the engine after it has cooled completely.
( → P. 509)
• The engine coolant temperature gauge indicator ( ) is in the red zone and flash- ing.
• The engine oil temperature gauge indicator ( ) is in the red zone and flashing.

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GS350_300_GS F_OM_OM30G34U_(U)4-2. Driving procedures
■Steering lock motor overheating prevention
To prevent the steering lock motor from over
heating, the motor may be suspended if the
engine is turned on and off re peatedly in a short period of time. In this case, refrain from
operating the engine. After about 10 seconds, the steering lock motor will resume func-
tioning.
■When “Check Access System with Elec. Key” will be displayed on the multi-informa-
tion display
The system may be malfunctio ning. Have the vehicle inspected by your Lexus dealer
immediately.
■If the electronic key battery is depleted
→ P. 410
■Operation of the engine switch
●If the switch is not pressed shortly and firmly, the engine switch mode may not change
or the engine may not start.
●If attempting to restart the engine immediately after turning the engine switch off, the
engine may not start in some cases. After turning the engine switch off, please wait a
few seconds before restarting the engine.
■If the smart access system with push-button start has been deactivated in a customized
setting
→ P. 501
WARNING
■When starting the engine
Always start the engine while sitting in the driver’s seat. Do not depress the accelerator
pedal while starting the engine under any circumstances.
Doing so may cause an accident resu lting in death or serious injury.
■Caution while driving
If engine failure occurs while the vehicle is moving, do not lock or open the doors until
the vehicle reaches a safe and complete stop. Activation of the steering lock in this cir-
cumstance may lead to an accident, re sulting in death or serious injury.
■Stopping the engine in an emergency
If you want to stop the engine in an emergency while driving the vehicle, press and hold
the engine switch for more than 2 seconds, or press it briefly 3 times or more in succes-
sion. ( →P. 425)
However, do not touch the engi ne switch while driving except in an emergency. Turning
the engine off while driving will not cause lo ss of steering or braking control, but the
power assist to these systems will be lost. Th is will make it more difficult to steer and
brake, so you should pull over and stop the vehicle as soon as it is safe to do so.

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GS350_300_GS F_OM_OM30G34U_(U)4-2. Driving procedures
■Parking brake operation
●When the engine switch is not in IGNITION ON mode, the parking brake cannot be
released using the parking brake switch.
●When the engine switch is not in IGNITION 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 will return after about 1 minute.
●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 so und (whirring sound) may be heard. This
does not indicate a malfunction.
■Parking brake indicator light
●Depending on the engine switch mode, the parking brake indicator light will come on
and stay on as described below:
IGNITION ON mode: Comes on unt il the parking brake is released.
Not in IGNITION ON mode: Stays on for approximately 15 seconds.
●When the engine switch is turned off with the parking brake set, the parking brake indi-
cator light will stay on for about 15 seconds. This does not in dicate a malfunction.
■When there is a malfunction in the system
Warning lights and/or warning message will turn on or flash. ( →P. 436, 442)
Depending on the condition, the park ing brake indicator light may flash.
■Parking the vehicle
→P. 182
■Parking brake engaged warning buzzer
→P. 445
■Usage in winter time
→P. 297
NOTICE
■When parking the vehicle
Before you leave the vehicle, set the parking brake, shift the shift lever to P and make
sure that the vehicle does not move.
■When the system malfunctions
Stop the vehicle in a safe place and check the warning messages.
■When the parking brake cannot be released due to a malfunction
Use the parking brake release tool to manually release the parking brake. (→P. 499)
Driving the vehicle with the parking brake se t will lead to brake components overheat-
ing, which may affect braking performance and increase brake wear.

GS350_300_GS F_OM_OM30G34U_(U)
2934-5. Using the driving support systems
4
Driving
■Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC, Hill-start assist
control and VGRS systems
●A sound may be heard from the engine compartment when the brake pedal is
depressed repeatedly, when the engine is started or just after the vehicle begins to
move. This sound does not indicate that a malfunction has occurred in any of these sys-
tems.
●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 afte r the vehicle comes to a stop.
• The brake pedal may pulsate slig htly after the ABS is activated.
• The brake pedal may move down s lightly after the ABS is activated.
■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 TRAC and VSC systems
After turning the TRAC and VSC systems off, the systems will be automatically re-
enabled in the following situations:
●When the engine swit ch is turned off
●If only the TRAC system is turned off, the TRAC will turn on when vehicle speed
increases
If both TRAC 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 engine off. The EPS system should return to normal
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.
■Automatic system cancelation of hill-start assist control
The hill-start assist control will be cancel ed in any of the following situations;
●The shift lever is shifted to N or P.
●The accelerator pedal is depressed.
●The parking brake is engaged.
●Approximately 2 seconds elapse after the brake pedal is released.

322
GS350_300_GS F_OM_OM30G34U_(U)5-2. Using the air conditio
ning system and defogger
Heated steering wheel∗/seat heaters∗/seat ventilators∗
Turns the heated steering wheel on/off
The indicator light comes on when the
heater is operating.
●The heated steering wheel can be used when the engine switch is in IGNITION ON
mode.
●The heated steering wheel will automati cally turn off after about 30 minutes.
∗: If equipped
Heated steering wheel and seat heaters heat the side grips of the steering
wheel and seats, respectively. Seat ventilators maintain good airflow by blow-
ing air from the seats.
WARNING
●Care should be taken to prevent injury if anyone in the following categories comes in
contact with the steering wheel or seats when the heater is on:
• Babies, small children, the elderly, the sick and the physically challenged
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (sleeping drugs, cold
remedies, etc.)
●Observe the following precautions to pr event the minor burns or overheating:
• Do not cover the seat with a blanket or cushion when using the seat heater.
• Do not use seat heater more than necessary.
NOTICE
●To prevent damage to the seat heaters/seat ventilators, do not put heavy objects that
have an uneven surface on the seat and do not stick sharp objects (needles, nails, etc.)
into the seat.
●To prevent battery discharge, do not us e the functions when the engine is off.
Heated steering wheel (If equipped)

4477-2. Steps to take in an emergency
GS350_300_GS F_OM_OM30G34U_(U)
7
When trouble arises
(If equipped)
Indicates that the LKA (Lane- Keeping Assist) system has
determined that the driver does not have their hands on
the steering wheel while the steering control function is
on If the driver operates the steering wheel only a small
amount, the system may be unable to detect the steer-
ing wheel operations and this warning may be dis-
played.
A buzzer also sounds.
→ Firmly hold the steering wheel.
(If equipped)
Indicates that steering control function is temporarily
canceled due to the LKA (Lane-Keeping Assist) system
determining that the driver does not have their hands on
the steering wheel while the steering control function is
on
If the driver operates the steering wheel only a small
amount, the system may be unable to detect the steer-
ing wheel operations and this warning may be dis-
played.
→ 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 your Lexus dealer.
Warning messageDetails/Actions
(U.S.A.) (Canada)
(U.S.A.) (Canada)

509
GS350_300_GS F_OM_OM30G34U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge (→P. 86, 92) enters the
red zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display.
●Steam is coming from under the hood.
Stop the vehicle in a safe place and tu rn off the air conditioning system, and
then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down sufficiently, inspect the hoses and cooling
core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The following may indicate that your vehicle is overheating.
Correction procedures
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