engine overheat Lexus GX460 2010 Operating Other Driving Systems / LEXUS 2010 GX460 (OM60E69U) User Guide

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2-4. Using other driving systems
2
When driving
GX460_U.S.A. (OM60E69U)
■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 that the shift lever be shifted to
2 or 1 range of S mode.
■If the four-wheel drive control switch is in H4
The system does not operate.
■When the downhill assist control system is operated continuously
This may cause the brake actuator to overheat. In this case, the downhill assist con-
trol system will stop operating, a buzzer will sound and the DAC indicator will start
flashing, and the TRAC OFF will be shown on the multi-information display. Refrain
from using the system until the DAC indicator stays on and the message goes off.
(The vehicle can be driven normally during this time.)
■Sounds and vibrations caused by the DAC
●A sound may be heard from the engine compartment when the engine is
started or just after the vehicle begins to move. This sound does not indicate that
a malfunction has occurred in DAC.
●Either of the following conditions may occur when the DAC 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 after the vehicle comes to a stop.
■System malfunction
●The DAC indicator does not come on when the “ENGINE START STOP”
switch is turned to IGNITION ON mode.
●The “DAC” indicator does not come on when the “DAC” switch is pressed.
●The slip indicator comes on.
In the above cases, have your vehicle checked by your Lexus dealer.

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2-5. Driving information
GX460_U.S.A. (OM60E69U)●
Avoid jerky starts or sudden acceleration.
● Avoid jerky steering and sharp turns, and slow down before making
turns.
● Note that when making a turn, the tr ailer wheels will be closer than the
vehicle wheels to the inside of the turn. Compensate by making a
larger than normal turning radius.
● Crosswinds and rough roads will adve rsely affect handling of your
vehicle and trailer, causing sway. Periodically check the rear to prepare
for being passed by large trucks or buses, which may cause your vehi-
cle and trailer to sway. If swaying occurs, firmly grip the steering wheel,
reduce speed immediately but gradua lly, and steer straight ahead.
Never increase speed. If you make no extreme correction with the
steering or brakes, your vehi cle and trailer will stabilize.
● Take care when passing other vehicl es. Passing requires considerable
distance. After passing a vehicle, do not forget the length of your
trailer, and be sure you have plenty of room before changing lanes.
● In order to maintain efficient eng ine braking and electrical charging
performance, do not use overdrive. Transmission shift range position
must be in 5, in S mode.
● Due to the added load of the trailer, your vehicle’s engine may overheat
on hot days (at temperatures over 85 °F [30 °C]) when driving up a
long or steep grade. If the engine coolant temperature gauge indicates
overheating, immediately turn off the air conditioning (if in use), pull
your vehicle off the road and stop in a safe spot. (
P. 74 4 )

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3-7. Other interior features
3
Interior features
GX460_U.S.A. (OM60E69U)
CAUTION
■Burns
●Use caution when seating the following persons in a seat with the seat heater on
to avoid the possibility of burns:
• 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.)
●Do not cover the seat with anything when using the seat heater. 
Using the seat heater with a blanket or cushion increases the temperature of the
seat and may lead to overheating.
●Do not use the seat heater more than necessary. Doing so may cause minor
burns or overheating.
NOTICE
■To prevent damage to the se at heaters and ventilators
Do not put heavy objects that have an unev en surface on the seat and do not stick
sharp objects (needles, nail s, etc.) into the seat.
■To prevent battery discharge
Turn the seat heaters and ventilators off when the engine is not running.

When trouble arises5
673
GX460_U.S.A. (OM60E69U)
5-1. Essential informationEmergency flashers ............... 674
If your vehicle needs 
to be towed ............................ 675
If you think something is 
wrong ....................................... 681
Fuel pump shut off  system..................................... 682
Event data recorder.............. 683
5-2. Steps to take in 
an emergency
If a warning light turns 
on or a warning buzzer 
sounds... ................................. 686
If a warning message is 
displayed................................ 698
If you have a flat tire............... 720
If the engine will not start .... 734
If the shift lever cannot be 
shifted from P ....................... 736
If you lose your keys ............... 737
If the electronic key does 
not operate properly.......... 738
If the vehicle battery is 
discharged .............................. 741
If your vehicle overheats ...... 744
If the vehicle becomes 
stuck......................................... 747

744
5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
If your vehicle overheats
If the engine overheats:
Stop the vehicle in a safe place and turn off the automatic air
conditioning system.
Check to see if steam is coming out from under the hood.
If you see steam: 
Stop the engine. Carefully lift the hood after the steam sub-
sides and then restart the engine.
If you do not see steam: Leave the engine running and carefully lift the hood.
Remove the engine compartment covers. ( P. 6 0 9 )
Check to see if the cooling fan is operating.
If the fan is operating: 
Wait until the engine coolant temperature gauge begins to
fall and then stop the engine.
If the fan is not operating: 
Stop the engine and call your local Lexus dealer.STEP1
STEP2
STEP3
STEP4

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5-2. Steps to take in an emergency
GX460_U.S.A. (OM60E69U)
■Overheating
In the following situations, your vehicle may be overheating:
●The engine coolant temperature gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
CAUTION
■To prevent an accident or injury when in specting under the hood of your vehicle
●If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartm ent may be very hot, causing serious
injury such as burns.
●Keep hands and clothing away from the fan and engine drive belt while the
engine is running.
●Do not loosen the coolant reservoir cap while the engine and radiator are hot.
Serious injury, such as burns, may resu lt from hot coolant and steam released
under pressure.
NOTICE
■When adding engine coolant
Wait until the engine has cooled down before adding coolant.
When adding coolant, do so slowly. Adding cold coolant to a hot engine too quickly
can cause damage to the engine.

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Alphabetical index
GX460_U.S.A. (OM60E69U)
Conversation mirror ...........................534
Cool box...................................................528
Cooling systemEngine overheating .......................... 744
Cornering assist sensors ...................259
Crawl Control........................................323
Cruise control Cruise control ..................................... 242
Dynamic radar cruise control ..... 246
Cup holders ............................................ 522
Curtain shield airbags............................ 121
Customizable features ........................ 781
Daytime running light system .......... 224
DAC........................................................... 327
Defogger Rear window ........................................ 404
Side mirror ............................................404
Dimension ................................................750
Dinghy towing ....................................... 380
Display Dynamic radar cruise control ..... 246
Multi-information 
display ........................................ 204, 212
Trip information ........................ 204, 212
Warning message............................ 698
Do-it-yourself maintenance .............602
Door courtesy lights Door courtesy lights............................ 511
Wattage.................................................... 761
Door pocket............................................520
Doors Back door................................................. 54
Power windows..................................... 101
Door lock...........................................48, 51
Rear door child protector ................ 52 Side doors.................................................. 51
Side mirrors.............................................. 97
Downhill assist control system ........ 327
Driver’s seat belt reminder light ..... 690
Driving Correct posture..................................... 119
Off-road precautions...................... 348
Procedures.............................................168
Winter driving tips .............................. 361
Driving position memory...................... 79
Electronic key If the electronic key does not 
operate properly............................ 738
Emergency, in case of If the electronic key does not 
operate properly............................ 738
If the engine will not start ................734
If the shift lever cannot be 
shifted from P....................................736
If the vehicle has discharged 
battery ................................................... 741
If the warning buzzer sounds...... 686
If the warning light turns on.......... 686
If the warning message is 
displayed ............................................ 698
If you have a flat tire .........................720
If you lose your keys ......................... 737
If you think something is 
wrong ....................................................681
If your vehicle becomes stuck ..... 747
If your vehicle needs to be 
towed ................................................... 675
If your vehicle overheats.................744
Emergency flashers Switch .......................................................674
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Alphabetical index
GX460_U.S.A. (OM60E69U)
EngineAccessory mode ................................. 179
Compartment .................................... 608
Engine switch ........................................ 179
Hood ....................................................... 607
How to start the engine.................... 179
Identification number......................... 751
If the engine will not start ................734
Ignition switch........................................ 179
Overheating..........................................744
Engine compartment cover............. 609
Engine coolant Capacity................................................. 755
Checking .................................................615
Preparing and checking 
before winter ...................................... 361
Engine coolant temperature 
gauge ....................................................... 195
Engine immobilizer system ..................114
Engine oil Capacity................................................. 753
Checking .................................................610
Preparing and checking 
before winter ...................................... 361
Engine oil maintenance data ............. 612
Engine switch ........................................... 179
Engine switch light .................................. 511
Event data recorder............................ 683
Floor mats................................................ 556
Fluid Brake .........................................................618
Power steering ................................... 620
Washer ................................................... 626 Fog lights
Replacing light bulbs ....................... 664
Switch....................................................... 233
Wattage ....................................................761
Footwell light .............................................511
Four-wheel drive system .....................317
Front passenger occupant 
classification system .......................... 140
Front passenger’s seat belt 
reminder light......................................690
Front seats Adjustment ............................................... 64
Driving position memory .................. 79
Front side marker light Replacing light bulbs ....................... 665
Wattage ....................................................761
Front turn signal lights Replacing light bulbs ....................... 666
Switch.........................................................192
Wattage ....................................................761
Fuel Capacity ................................................. 752
Fuel gauge.............................................. 195
Fuel pump shut off system............ 682
Gas station information ..................824
Information ............................................ 762
Refueling.................................................. 109
Fuel door ................................................... 109
Fuel filler door ......................................... 109
Fuel pump shut off system .................682
Fuses .......................................................... 645
F

815
Alphabetical index
GX460_U.S.A. (OM60E69U)
Kinetic Dynamic Suspension 
System (KDSS) .................................... 331
Lane Departure Alert......................... 268
LDA ........................................................... 268
License plate lights Replacing light bulbs ....................... 670
Light bulbs Replacing...............................................660
Wattage ................................................... 761
Lights Door courtesy lights ............................511
Emergency flasher switch ............. 674
Engine switch light ................................511
Fog light switch................................... 233
Hazard light switch........................... 674
Headlights switch .............................. 220
Inside door handle light......................511
Interior lights list .....................................511
Personal/interior lights ..................... 513
Replacing light bulbs .......................660
Running board lights ...........................511
Scuff lights .................................................511
Shift lever light .........................................511
Turn signal lever................................... 192
Vanity lights .......................................... 532
Wattage ................................................... 761
Load capacity ........................................ 359
Luggage cover ...................................... 560
Maintenance Do-it-yourself maintenance ......... 602
General maintenance ..................... 597
Maintenance data ............................. 750
Maintenance requirements ..........595 Meter
Instrument cluster light 
control ................................................... 196
Meters....................................................... 195
Micro dust and pollen filter............... 394
Mirrors Inside rear view mirror .......................96
Side mirror heater ............................ 404
Side mirrors ............................................. 97
Vanity mirrors ......................................532
Moon roof ................................................. 104
MP3 disc .................................................. 424
Multi-information display Brightness control ...............................216
Multi-information display ........ 204, 212
Multi Terrain ABS.................................330
Multi-terrain Monitor..........................298
Multi-terrain Select ..............................290
Noise from under vehicle..................... 20
Odometer................................................. 195
Off-road precautions..........................348
Oil Engine oil................................................. 610
Opener Fuel filler door ....................................... 109
Hood ....................................................... 607
Outside rear view mirrors Adjusting and folding.......................... 97
Driving position memory .................. 79
Outside temperature display ............212
Overhead console ...............................525
Overheating, Engine........................... 744
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GX460_U.S.A. (OM60E69U)
What to do if...
What to do if...
A tire puncturesP. 7 2 0If you have a flat tire
The engine does not start
P. 1 1 4Engine immobilizer system
P. 7 3 4If the engine will not start
P. 74 1If the battery is discharged
The shift lever cannot be 
moved outP. 7 3 6If the shift lever cannot be shifted 
from “P”
The engine coolant temperature
gauge enters the red zone
Steam can be seen coming 
from under the hood
P. 74 4If your vehicle overheats
The key is lostP. 7 3 7If you lose your keys
The battery is dischargedP. 74 1If the vehicle has a discharged battery
The doors cannot be lockedP. 5 1Side doors
P. 5 4Back door
The horn begins to soundP. 1 1 6Alarm
The vehicle is stuck in mud or
sandP. 74 7If the vehicle becomes stuck