2020 Lexus GX460 engine overheat

338
GX460_OM_OM60R27U_(U)4-5. Using the driving support systems
WARNING
■The rear height control air suspension must be turned off
Be sure to observe the following precautions. Otherwise, the automatic leveling func-
tion may cause vehicle height to change, an
d you may catch part of your body in the
vehicle, resulting in an accident:
●When jacking up the vehicle, installing tire chains or tying the vehicle with chains/
wires for transportation via flatbed truck, tu rn off the rear height control air suspen-
sion and stop the engine.
●When the vehicle must be towed or disconnect ing a trailer, put the vehicle height in N
mode and turn off the rear he ight control air suspension.
●When the vehicle is stuck, turn off the rear height control air suspension.
■Selecting the correct height mode
●HI mode should only be used when drivin g on rough roads, for example when driving
off-road.
Because the vehicle’s center of gravity will become higher when in the mode, the
vehicle may become unstable when turnin g abruptly, resulting in an accident.
●Do not select HI mode when loading cargo on the roof luggage carrier.
Because the vehicle’s center of gravity will become higher when in the mode, the
vehicle may become unstable when turnin g abruptly, resulting in an accident.
●Before lowering vehicle height, check that there is no one under the vehicle.
NOTICE
■Be careful in any place where overhead space is limited
The vehicle height will rise when a higher mode is selected or cargo is unloaded. This
may cause damage to the vehicle.
■Do not select LO mode when driving on bumpy roads
If the underbody of the vehicle touches a rugged road surface, the vehicle may be
damaged.
■Changing vehicle height
Do not change vehicle height frequently.
The compressor may overheat and stop operation.
■When on the extremely uneven roads with rocks
Sometimes the vehicle height is not adjusted because it is judged as uneven road driv-
ing.

GX460_OM_OM60R27U_(U)
3474-5. Using the driving support systems
4
Driving
■When the Crawl Control system is operated continuously
This may cause the brake actuator to overheat . In this case, the Crawl Control system will
stop operating, a buzzer will sound, the Crawl Control indicator will turn off after flashing
and the “TRAC OFF” indicator will come on. In this case, quickly stop the vehicle in a safe
place and give the actuator adequate time to cool off. Refrain from using the system until
the “TRAC OFF” indicator turns off. (The ve hicle can be driven normally during this
time.)
■When depressing the accelerator pedal while the Crawl Control is operating
Multi-terrain Select operates in AUTO mode. ( P. 284)
■If the automatic transmission system overheats
The system will cease operation, a buzzer w ill sound and a warning message will be dis-
played to alert the driver. Stop the vehicle in a safe place until the warning message turns
off. ( P. 521)
■Sounds and vibrations caused by the Crawl Control system
●A sound may be heard from the engine compartment when the engine is started or just
after the vehicle begins to move. This soun d does not indicate that a malfunction has
occurred in Crawl Control system.
●Either of the following conditions may occu r when the Crawl Control system is operat-
ing. None of these are indicators 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.
■If the slip indicator comes on...
It may indicate a malfunction in the system. Cons ult your Lexus dealer.
WARNING
■When using Crawl Control
Do not rely solely on the Crawl Control. This function does not extend the vehicle’s
performance limitations. Always thoroughly check the road conditions, and drive
safely.
■These conditions may cause the system not to operate properly
When driving on the following surfaces, the sy stem may not be able to maintain a fixed
low speed, which may re sult in an accident:
●Extremely steep inclines.
●Extremely uneven surfaces.
●Snow-covered roads, or other slippery surfaces.

GX460_OM_OM60R27U_(U)
3494-5. Using the driving support systems
4
Driving
■Operating tips
The system will operate when the shift lever is in a position other than P, however to make
effective use of the system it is recommended to select a lower shift range.
■The system will not operate when
The transfer mode is in H4.
■If the downhill assist control system indicator flashes
●In the following situations, the indicator flashes and the system will not operate:
• The transfer mode is not in L4.
• The shift lever is in P.
• The accelerator or brake pedal is depressed.
• The vehicle speed exceeds approximately 15 mph (25 km/h).
• The brake system overheats.
●In the following situations, the indicator flas hes to alert the driver, but the system will
operate:
• The shift lever is in N.
• The “DAC” switch is turned of f while the system is operating.
The system will gradually ceas es operation. The indicator will flash during operation,
and then go off when the system is fully off.
■When the downhill assist control system is operated continuously
This may cause the brake actuator to overheat. In this case, the downhill assist control
system will stop operating, a buzzer will sound and the downhill assist control system
indicator will start flashing, and the “TRAC OFF” indicator light will come on. Refrain
from using the system until the downhill assi st control system indicator stays on and
“TRAC OFF” indicator light turns off. (The vehicle can be driven normally during this
time.)
■Sounds and vibrations caused by the downhill assist control system
●A sound may be heard from the engine compartment when the engine is started or just
after the vehicle begins to move. This soun d does not indicate that a malfunction has
occurred in downhill assist control system.
●Either of the following conditions may occur when the do wnhill assist control system is
operating. None of these are indicators 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.
■System malfunction
In the following cases, have your vehicle checked by your Lexus dealer.
●The downhill assist control system indicator does not come on when the engine switch
is turned to IGNITION ON mode.
●The downhill assist control system indicator does not come on when the “DAC” switch
is shifted to ON.
●The slip indicator comes on.

354
GX460_OM_OM60R27U_(U)4-5. Using the driving support systems
■Sounds and vibrations caused by the ABS/Mu
lti Terrain ABS, brake assist, VSC, Trailer
Sway Control, TRAC/Active TRAC and hill-start assist control 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 also after the vehicle comes to a stop.
• The brake pedal may pulsate slightly afte r the ABS/Multi Terrain ABS is activated.
• The brake pedal may move down slightly after the ABS/Multi Terrain ABS is acti-
vated.
■Automatic reactivation of TRAC/Active TR AC, Trailer Sway Control and VSC systems
After turning the TRAC/Activ e TRAC, Trailer Sway Control and VSC systems off, the
systems will be automatically re-ena bled in the following situations:
●When the engine switch is turned off
●If only the TRAC/Active TRAC system is turned off, the TRAC/Active TRAC will turn
on when vehicle speed increases
If both the TRAC/Active TRAC and VSC syst ems are turned off, automatic re-enabling
will not occur when vehicle speed increases.
■When the brake system operates continuously
The brake actuator may overheat. In this case, the TRAC/Active TRAC and hill-start
assist control systems will stop operating, a buzzer will sound and the “TRAC OFF” indi-
cator will come on. Refrain from using the system until the message goes off. (There is no
problem with continuing normal driving.)
■If the slip indicator comes on...
It may indicate a malfunction in the TRAC /Active TRAC, VSC/Trailer Sway Control or
hill-start assist control system. Consult your Lexus dealer.
■KDSS
Some difference of vehicle height between left and right side can appear. This does not
indicate a malfunction in the KDSS system. For more information, contact your Lexus
dealer.

389
GX460_OM_OM60R27U_(U)5-1. Using the air conditio
ning system and defogger
5
Interior features
Heated steering wheel/seat heaters/seat
ventilators

Turns the heated steering wheel on/off
The indicator light comes on when the
heated steering wheel is operating.
: If equipped
Heated steering wheel and seat heaters heat the side grips of the steering
wheel and seats. Seat ventilators maintain good airflow by blowing 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 and 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
●Do not put heavy objects that have an unev en 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)

499
GX460_OM_OM60R27U_(U)
7When trouble arises
7-1. Essential informationEmergency flashers ................. 500
If your vehicle has to be stopped in
an emergency ........................... 501
If the vehicle is trapped in rising water ................................502
7-2. Steps to take in an emergency If your vehicle needs to be towed................................503
If you think something is wrong ...........................................509
Fuel pump shut off system ....... 510
If a warning light turns on or a warning buzzer
sounds............................................. 511
If a warning message is displayed.....................................520
If you have a flat tire .................. 524
If the engine will not start ........538
If the electronic key does not operate properly .............540
If the vehicle battery is discharged ................................. 543
If your vehicle overheats ......... 546
If the vehicle becomes stuck ............................................. 549

546
GX460_OM_OM60R27U_(U)7-2. Steps to take in an emergency
If your vehicle overheats
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 suff iciently, inspect the hoses and radiator
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.
●The needle of the engine coolant temperature gauge ( P. 88) enters the
red zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●Steam is coming from under the hood.
Correction procedures
1
2
3
1
2

608Alphabetical index
GX460_OM_OM60R27U_(U)
Console box ........................................... 396
Cool box .................................................. 409
Cooling system ..................................... 455Engine overheating.......................... 546
Conversation mirror ............................. 412
Crawl Control ....................................... 344
Cruise control Dynamic radar cruise control......254
Cup holders ............................................ 398
Curtain shield airbags ........................... 36
Current fuel consumption ................... 93
Customizable features ....................... 576
DAC (Downhill Assist Control system)................................................... 348
Daytime running light system ........... 210
Defogger Front windshield ................................ 380
Outside rear view mirrors .............. 381
Rear window ......................................... 381
Differential ............................................... 557
Dimension ............................................... 552
Display Drive information .................................. 93
Multi-information display ....................91
Warning message ............................ 520
Do-it-yourself maintenance ............. 447
Doors.......................................................... 104 Back door ................................................... 111
Door glasses ......................................... 156
Door lock ................................................ 104
Open door warning light................ 513
Outside rear view mirrors .............. 153
Rear door child-protector.............. 107
Drive information .................................... 93
Drive-Start Control ...............................166 Driver’s seat position memory............141
Driving ........................................................ 164
AVS switch ........................................... 339
Break-in tips ...........................................166
Correct posture .................................... 28
Procedures .............................................164
Winter drive tips ................................ 367
Dynamic radar cruise control ..........254
Eco Driving Indicator .............................96
EDR (Event data recorder)................... 10
Electronic key ......................................... 100 Battery-saving function .................... 123
If the electronic key does not operate properly ............................540
Replacing the battery ...................... 484
Emergency, in case of If the electronic key does not operate properly ............................540
If the engine will not start ...............538
If the vehicle has discharged battery ........................ 543
If the vehicle is trapped in rising water.....................................................502
If the warning buzzer sounds ......... 511
If the warning light turns on ............. 511
If you have a flat tire .......................... 524
If you lose your keys................. 101, 103
If you think something is wrong.................................................. 509
If your vehicle becomes stuck...................................................... 549
If your vehicle needs to be towed ...................................................503
If your vehicle overheats ................ 546
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