2003 Lexus GX470 overheating

SWITCHES
37
SEAT HEATER SWITCHES
The seat heater has two dials; one marked “L” (for the
driver’s seat) and the other marked “R” (for the front
passenger’s seat). To turn the seat heaters on, turn the
dials forward. The indicator lights come on. To turn them
off, turn the dials backward until they stop. The indicator
lights go off.
You can adjust the heating temperature to 5 stages. To
increase the temperature, turn them forward. To decrease the
temperature, turn them backward.
The ignition key must be in the “ON” position.
CAUTION
Occupants must use caution when operating the seat
heater because they may experience minor burns even
at low temperatures. Use extra caution for;
 Babies, small children, elderly persons, sick persons
or handicapped persons
 Persons who have delicate skin
 Persons who are exhausted
 Persons who have taken alcohol or drugs which
induce sleep (sleeping drug, cold remedy, etc.).
To prevent the seat from overheating, do not use the
seat heater with a blanket, cushion, or other insulating
objects which cover the seat.
NOTICE
 Do not put unevenly weighted objects on the seat and
do not stick sharp objects (needles, nails, etc.) into
the seat.
 When cleaning the seats, do not use organic
substances (paint thinner, benzine, alcohol,
gasoline, etc.). They may damage the heater and seat
surface.
 To prevent the battery from being discharged, turn
the switches off when the engine is not running.

STARTING AND DRIVING
307
(c) Using the “3”, “2” and “L” positions
The “3”, “2” and “L” positions are used for strong engine\
braking
as described previously.
With the selector lever in “3”, “2” or “L”, you can start the vehicle
in motion as with the lever in “D”.
With the selector lever in “3” or “2”, the vehicle will start in firs\
t
gear and automatically shift to second gear.
With the selector lever in “L”, the transmission is engaged in
first gear.
NOTICE
 Be careful not to overrev the engine. Watch the
tachometer to keep engine rpm from going into the
red zone. The approximate maximum allowable
speed for each position is given below for your
reference:
Transmission Transfer
“L” “H”
“3” 53 km/h (33 mph) 136 km/h (85 mph)
“2” 36 km/h (22 mph) 93 km/h (58 mph)
“L” 21 km/h (13 mph) 54 km/h (33 mph)
 Do not continue hill climbing or hard towing for a long
time in the “3”, “2” or “L” position. This may cause
severe automatic transmission damage from
overheating. To prevent such damage, “4” position
should be used in hill climbing or hard towing.
(d) Backing up
 1 Brake pedal 2 “R” (Reverse) position
1. Bring the vehicle to a complete stop.
2. With the brake pedal held down with your foot, shift the
selector lever to the “R” position.
NOTICE
Never shift into reverse while the vehicle is moving.
When the shift lever is shifted into “R” position, the outside rear
view mirrors automatically down to help backing up. For
details, see page 116.

DRIVING TIPS
342
CAUTION
Before driving off, make sure the parking brake is
fully released and that the parking brake reminder
light is off.
 Do not leave your vehicle unattended while the
engine is running.
 Do not rest your foot on the brake pedal while driving.
It can cause dangerous overheating, needless wear,
and poor fuel economy.
 To drive down a long or steep hill, reduce your speed
and downshift. Remember, if you ride the brakes
excessively, they may overheat and not work
properly. See page 306.
 Be careful when accelerating, upshifting,
downshifting or braking on a slippery surface. The
abrupt change in engine speed, such as sudden
acceleration or engine braking, could cause the
vehicle to spin or skid.
 Do not drive in excess of the speed limit. Even if the
legal speed limit permits it, do not drive over 140 km/h
(85 mph) unless your vehicle has highspeed
capability tires. Driving over 140 km/h (85 mph) may
result in tire failure, loss of control and possible
injury. Be sure to consult a tire dealer to determine
whether the tires on your vehicle are highspeed
capability tires or not before driving at such speeds.
 Do not continue normal driving when the brakes are
wet. If they are wet, your vehicle will require a longer
stopping distance, and it may pull to one side when
the brakes are applied. Also, the parking brake will
not hold the vehicle securely.
 If you drive through deep water over about 500 mm
(20 in.) in depth, put the vehicle height in the HI (High)
mode with the active height select switch and then
turn off the active height control suspension by
pushing the height control switch. Drive your vehicle
at 30 km/h (19 mph) or lower speed.

DRIVING TIPS
355

Crosswinds and rough roads will adversely affect handling
of your vehicle and trailer, causing sway. Pay attention to
the rear from time to time to prepare yourself for being
passed by large trucks or buses, which may cause your
vehicle and trailer to sway. If swaying happens, firmly grip
the steering wheel and reduce speed immediately but
gradually. Never increase speed. If it is necessary to
reduce speed, brake slowly. Steer straight ahead. If you
make no extreme correction with the steering or brakes,
your vehicle and trailer will stabilize.
 Be careful when passing other vehicles. 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 engine braking and electrical
charging performance, do not use overdrive. Transmission
must be “4” position.
 Because of the added load of the trailer, your vehicle’s
engine may overheat on hot days (at temperatures over
30C [85 F]) when going up a long or steep grade with a
trailer. 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.
See “If your vehicle overheats” on page 363. 
Always pl ace wheel blocks under both the vehicle and trailer
wheels when parking. Apply the parking brake firmly. Put
the transmission in “P”. Avoid parking on a slope with a
trailer, but if it cannot be avoided, do so only after performing
the following:
1. Apply the brakes and keep them applied.
2. Have someone place wheel blocks under both the vehicle
and trailer wheels.
3. When the wheel blocks are in place, release your brakes
slowly until the blocks absorb the load.
4. Apply the parking brake firmly.
5. Shift into “P” and turn off the engine.

DRIVING TIPS
357

Avoid continuous speeding up and slowing down.
Stop−and−go driving wastes fuel.
 Avoid unnecessary stopping and braking. Maintain a
steady pace. Try to time the traf fic signals so you only need
to stop as little as possible or take advantage of through
streets to avoid traffic lights. Keep a proper distance from
other vehicles to avoid sudden braking. This will also
reduce wear on your brakes.
 Avoid heavy traffic or traffic jams whenever possible.
 Do not rest your foot on the brake pedal. This causes
premature wear, overheating and poor fuel economy.
 Maintain a moderate speed on highways. The faster you
drive, the greater the fuel consumption. By reducing your
speed, you will cut down on fuel consumption.
 Keep the front wheels in proper alignment. Avoid hitting
the curb and slow down on rough roads. Improper
alignment not only causes faster tire wear but also puts an
extra load on the engine, which, in turn, wastes fuel.
 Keep the bottom of your vehicle free from mud, etc. This
not only lessens weight but also helps prevent corrosion. 
Keep your vehicle tunedup and in top shape. A dirty air
cleaner, improper valve clearance, dirty plugs, dirty oil and
grease, brakes not adjusted, etc. all lower engine
performance and contribute to poor fuel economy. For
longer life of all parts and lower operating costs, keep all
maintenance work on schedule, and if you often drive under
severe conditions, see that your vehicle receives more
frequent maintenance. (For scheduled maintenance
information, please refer to the “Owner’s Manual
Supplement / Scheduled Maintenance”.)
CAUTION
Never turn off the engine to coast down hills. Your
power steering and brake booster will not function
without the engine running. Also, the emission control
system operates properly only when the engine is
running.

IN CASE OF AN EMERGENCY
363
IF YOU CANNOT INCREASE THEENGINE SPEED
If the engine speed does not increase with the accelerator
pedal depressed down, there may be a problem somewhere
in your electronic throttle control system.
At this time, vibration may occur. However, if you depress the
accelerator pedal more firmly and slowly, you can drive your
vehicle at low speeds. Have your vehicle checked by your
Lexus dealer as soon as possible.
Even if the abnormality of the electronic throttle control system
is corrected during low speed driving, the system may not be
recovered until the engine is stopped and the ignition key is
turned to “ACC” or “LOCK” position.
CAUTION
Be especially careful to prevent erroneous pedal
operation.
IF YOUR VEHICLE OVERHEATS
If your engine coolant temperature gauge indicates
overheating, if you experience a loss of power, or if you
hear a loud knocking or pinging noise, the engine has
probably overheated.
When the engine overheats
Pull safely off the road, stop the vehicle and turn on your
emergency flashers. Put the transmission in “P” and apply the
parking brake.
A: If steam is coming from your engine:
Turn off the engine. Leave the hood closed until there is no sign
of steam or coolant. Your engine could have been seriously
damaged already. Call your Lexus dealer for assistance.
CAUTION
To help avoid personal injury, keep the hood closed until
there is no steam. Escaping steam or coolant is sign of
very high pressure.