2010 Lexus GX460 engine overheat

326
2-4. Using other driving systems
GX460_U.S.A. (OM60E69U)
■Automatic system cancelation
In the following situations, the system is canceled automatically:
At that time, the buzzer will sound, the slip indicator turns off, and the Crawl Con-
trol indicator flashes. 
A notification will be displayed on the multi-information display for several seconds.
(  P. 6 9 8 )
●When the shift lever is moved to P or N.
●When the four-wheel drive control switch is in H4.
●When the driver’s door is opened.
When turning off Crawl Control while traveling, stop the vehicle before the Crawl
Control indicator turns off, or drive extremely carefully.
■Function limit
●In the following situations, you will be able to use brake control to drive downhill
at a fixed low speed, but you will be unable to use engine control to drive uphill
at a fixed low speed.
• When the driving mode is set to second start mode.
• When the vehicle speed is higher than 6 mph (10 km/h).
●In the following situation, engine contro l and brake control will stop temporarily: 
At that time, the Crawl Control indicator flashes.
When the vehicle speed is higher than 15 mph (25 km/h).
■When the Crawl Control system is operated continuously
This may cause the brake actuator to overheat. In this case, the Crawl Control sys-
tem will stop operating, a buzzer will sound, the Crawl Control indicator will turn off
after flashing and the TRAC OFF will be show n on the multi-information display. In
this case, quickly stop the vehicle in a sa fe place and give the actuator adequate
time to cool off. Refrain from using the sy stem until the message goes off. (The vehi-
cle can be driven normally during this time.)

327
2-4. Using other driving systems
2
When driving
GX460_U.S.A. (OM60E69U)
■If the automatic transmission system overheats
The system will cease operation, a buzzer will sound and a warning message will be
displayed to alert the driver. Stop the vehi cle in a safe place until the warning mes-
sage turns off. ( P. 6 9 8 )
■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 sound does not indicate that
a malfunction has occurred in Crawl Control system.
●Either of the following conditions may occur when the Crawl 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 after the vehicle comes to a stop.
■If the slip indicator comes on...
It may indicate a malfunction in th e system. Consult your Lexus dealer.
CAUTION
■When using Crawl Control
Do not rely solely on the Crawl Control. Th is 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, th e system may not be able to maintain a
fixed low speed, which may result in an accident:
●Extremely steep inclines.
●Extremely uneven surfaces.
●Snow-covered roads, or other slippery surfaces.

329
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.

378
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 )

553
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

746
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.