engine overheat Lexus GS430 2006 Scheduled Maintenance Guide / LEXUS 2006 GS430/GS300 FROM JAN. 2005 PROD. OWNER'S MANUAL (OM30649U)

SWITCHES
55
HEADLIGHT CLEANER SWITCH
The headlight cleaner switch is located in the switch box.
G12010
Push the button to use the switch box. To spray fluid on
the headlights, push the switch with the headlights on.
The engine switch must be selected in “IG−ON” mode.
The warning message “LOW WASHER FLUID” is displayed in
the multi−information display when the fluid level in the tank
becomes very low. For information on adding washer fluid, see
“Adding washer fluid” on page 579.
After operation, be sure to close the switch box to its original
position.
CAUTION
To reduce the chance of injury in case of an accident or
a sudden stop, keep the switch box closed when not in
use while driving.
NOTICE
Do not turn the headlight cleaner on with the washer
fluid tank empty. It may cause the cleaner motor to
overheat.

SWITCHES
62
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 persons with physical disabilities
 Persons who have sensitive 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.

SWITCHES
65
Seat heater
G12030
To turn on the seat heater, turn the dial as shown. The
indicator light (yellow) comes on.
The engine switch must be selected in “IG−ON” mode.
The heating level will be increased as you turn the dial to the
higher number.
To disable this function, turn the dial to the “0” position. The
indicator light goes off. Keep the dial in this position when not
in use.
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 persons with physical disabilities
 Persons who have sensitive 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.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
68
FUEL GAUGE
G13001
Low fuel level warning light
The gauge indicates the approximate quantity of fuel
remaining in the tank when the engine switch is selected
in “IGON” mode.
It is a good idea to keep the tank over 1/4 full.
If the fuel level approaches ”E” or the low fuel level warning light\
comes on, fill the fuel tank as soon as possible.
On inclines or curves, due to the movement of fuel in the tank,
the fuel gauge needle may fluctuate or the low fuel level
warning light may come on earlier than usual.
If the fuel tank is completely empty, the malfunction indicator
lamp comes on. Fill the fuel tank immediately.
The indicator lamp goes off after driving several times. If the
indicator lamp does not go off, contact your Lexus dealer as
soon as possible. See the inner back cover for fuel capacity and recommended
fuel selection.
ENGINE COOLANT
TEMPERATURE GAUGE
G13002
 Normal range
The gauge indicates the engine coolant temperature when
the engine switch is selected in “IGON” mode. The
engine operating temperature will vary with changes in
weather and engine load.
If the needle points to the red zone or higher, stop your vehicle
and allow the engine to cool.
Your vehicle may overheat during severe operating conditions,
such as:
 Driving up a long hill on a hot day.
 Reducing speed or stopping after high speed driving.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
69

Idling for a long period with the air conditioning on in
stop−and−go traffic.
NOTICE
Do not remove the thermostat in the engine cooling
system as this may cause the engine to overheat. The
thermostat is designed to control the flow of coolant
to keep the temperature of the engine within the
specified operating range.
 Do not continue driving with an overheated engine.
See ”If your vehicle overheats” on page 467.
TACHOMETER
G13003
The tachometer indicates engine speed in thousands of
rpm (revolutions per minute). Use it while driving to
prevent engine overrevving.
Driving with the engine running too fast causes excessive
engine wear and poor fuel economy. Remember, in most
cases the slower the engine speed, the greater the fuel
economy.
NOTICE
Do not let the indicator needle get into the red zone. This
may cause severe engine damage.

INTERIOR EQUIPMENT
121
To raise the sunshade again, perform any of the following
operations:

Shift the selector lever into the “P” position.
 Push the switch again.
 Move the selector lever out of “R” position and drive your
vehicle over 15 km/h (9 mph).
Retained accessory power: Even after the engine switch is
turned off, the sunshade can be operated for about 60
seconds.
CAUTION
 Do not touch the brackets fastening the shade to
avoid injuring your fingers or hands.
 Do not put your fingers in the shade groove while the
shade is operating to avoid getting them caught or
injured by the runner.
 To reduce the chance of injury in case of an accident
or a sudden stop, keep the switch box closed when
not in use while driving.
NOTICE
To prevent the vehicle battery from being discharged,
always operate the shade while the engine is running.
 Observe the following to avoid damage and/or
malfunction:
Do not overload the shade motor and other parts
(for instance by pushing down on the sunshade
bracket while it is opening).
Do not place anything where it may hinder the
opening/closing of the shade.
Do not affix anything to the shade.
Clean the shade groove if there is any foreign
matter or dust on it.
Do not operate the rear electric sunshade
repeatedly for a long time as its motor may
overheat.

STARTING AND DRIVING
340
THREEWAY CATALYTICCONVERTERS
G31042
GS430
G31043
GS300 Threeway catalytic converters are emission control
devices installed in the exhaust system.
The purpose is to reduce pollutants in the exhaust gas.
CAUTION

Keep people and combustible materials away from
the exhaust pipe while the engine is running. The
exhaust gas is very hot.
 Do not drive, idle or park your vehicle over anything
that might burn easily such as grass, leaves, paper or
rags.
NOTICE
A large amount of unburned gases flowing into the
threeway catalytic converter may cause it to overheat
and create a fire hazard. To prevent this and other
damage, observe the following precautions:
 Use only unleaded gasoline.
 Do not drive with an extremely low fuel level; running
out of fuel could cause the engine to misfire, creating
an excessive load on the threeway catalytic
converter.
 Do not allow the engine to run at idle speed for more
than 20 minutes.

STARTING AND DRIVING
363
(e) Parking
G31029
 1Parking brake pedal 2Brake pedal
3“P” (Park) position
1. Bring the vehicle to a complete stop.
2. Depress the parking brake pedal fully to securely apply the
parking brake.
3. With the brake pedal held down with your foot, shift the
selector lever to the “P” position.
CAUTION
Never attempt to move the selector lever into “P” under
any circumstances while the vehicle is moving. Serious
mechanical damage and loss of vehicle control may
result.
(f) Good driving practice
If the transmission repeatedly shifts up and down between
fourth and overdrive gears when climbing a gentle slope, shift
the selector lever to the “4” position. Be sure to shift the
selector lever to the “D” position after climbing the slope.
CAUTION
Always keep your foot on the brake pedal while stopped
with the engine running. This prevents the vehicle from
creeping.
NOTICE
Always use the brake pedal or the parking brake to hold
the vehicle on an upgrade. Do not attempt to hold the
vehicle using the accelerator pedal, as this can cause
the transmission to overheat.

STARTING AND DRIVING
424
Hillstart assist control system failure
warning
G31039
 1GS430 2GS300
If the hillstart assist control system malfunctions, the
slip indicator light (twowheel drive models only) and
brake system warning light (yellow) come on. At this time,
the above message appears. (GS430 only—In some
cases, the multiinformation display shows either
“CHECK VSC” or “CHECK ECB” only.)
If the message appears, the hill−start assist control system,
vehicle stability control system and traction control system do
not work. Although it is no problem to continue driving, have
your vehicle checked by your Lexus dealer as soon as
possible.
VARIABLE GEAR RATIO STEERING SYSTEM (GS430 only)
The variable gear ratio steering system adjusts the wheel
turning angle depending on the vehicle speed and how
much you turn the steering wheel.
The vehicle wheel turning angle will be changed with a smaller
degree of wheel maneuvering when you are driving at very low
speed such as when putting your vehicle into a garage.
When you start or stop the engine, you may hear a small noise
and the steering wheel may move slightly. This is caused when
the system starts or stops, and does not indicate a malfunction.
In the following cases, to prevent the system from overheating,
the system could be temporarily deactivated with the change
in the center position of the steering wheel. This is not a
malfunction. After the cause of the problem is eliminated, the
system will return to normal automatically after a few minutes.
 If you continue maneuvering the steering wheel when the
vehicle is stopped or running at very low speed
 If you continue driving holding the steering wheel to the
extreme right or left
 If you maneuver the steering wheel immediately after
starting the engine at less than about −30C (− 22F)

STARTING AND DRIVING
432
ELECTRIC POWER STEERINGSYSTEM
The electric power steering system, using an electric
motor, assists the turning of the steering wheel.
In the following cases, you may feel the steering becomes
heavy. However, the electric power steering system
warning light does not come on. (Because it is not a
malfunction.)
When maneuvering or turning frequently over a long time, the
power steering effect will be reduced to prevent the system
from overheating. A void turning the steering wheel, or stop the
vehicle and select the engine switch in “ACC” or “OFF” mode.
The system will become cool in about 10 minutes.
NOTICE
Frequent maneuvering and turning over a long time may
cause damage to the system in which the mechanism
prevents overheating of the electric power steering
system.
When the battery is discharged, check the battery’s condition.
If necessary, recharge or replace the battery. For details, see
“Checking battery condition” on page 571.
G31040
 Electric power steering system warning light
The light comes on when the engine switch is selected in
“IG−ON” mode. If the electric power steering system works
properly, the light turns off after a few seconds. If the system
has malfunctions, the light comes on again.
If the following conditions occur, this indicates a
malfunction somewhere in the components monitored by
the warning light system. Contact your Lexus dealer as
soon as possible to service the vehicle.
 The light does not come on when the engine switch is
selected in “IG −ON” mode or remains on.
 The light stays on while you are driving.