Lexus GS430 2006 Scheduled Maintenance Guide / LEXUS 2006 GS430/GS300 FROM JAN. 2006 PROD. OWNER'S MANUAL (OM30786U)

STARTING AND DRIVING
437
If any of 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 engine switch is selected
in “IG− ON” mode.
 The light remains on after the engine is started (GS430), or
remains on a few seconds after the engine switch is
selected in “IG −ON” mode (GS300).
 The light comes on while you are driving.
A warning light turning on briefly during operation does not
indicate a problem.
CAUTION
If the “ABS” warning light remains on together with the
brake system warning light (red), immediately stop your
vehicle at a safe place and contact your Lexus dealer.
In this case, not only the antilock brake system will fail
but also the vehicle will become extremely unstable
during braking.
GS430 only—Either of the following conditions may
occur, but does not indicate a malfunction:
 The light may stay on for about 60 seconds after the engine
is started. It is normal if it turns off after a while.
 Depressing the brake pedal repeatedly may turn on the
light. It is normal if it turns off after a few seconds.
Drumindisc type parking brake system
Your vehicle has a drum−in−disc type parking brake system.
This type of brake system needs bedding −down of the brake
shoes periodically or whenever the parking brake shoes
and/or drums are replaced.
Have your Lexus dealer perform the bedding −down.
Brake assist system
When you slam the brakes on, the brake assist system
judges as an emergency stop and provides more powerful
braking for a driver who cannot hold down the brake pedal
firmly.
When you slam the brakes on, more powerful braking will be
applied. At this time, you may hear a sound in the engine
compartment and feel the vibrations of the brake pedal. This
does not indicate a malfunction.
The brake assist system becomes operative after the vehicle
has accelerated to a speed in excess of approximately 10 km/h
(6 mph). It stops operating when the vehicle decelerates to a
speed below approximately 5 km/h (3 mph).
The brake assist system may not work for about 60 seconds
after the engine is started.
For an explanation of this system’s warning light, see “ABS”
warning light on page 80 or 436.

STARTING AND DRIVING
438
BRAKE PAD WEAR LIMITINDICATORS
G31006
The brake pad wear limit indicators on your disc brakes
give a warning noise when the brake pads are worn to the
extent that replacement is required.
If you hear a squealing or scraping noise while driving, have
the brake pads checked and replaced by your Lexus dealer as
soon as possible. Expensive rotor damage can result if the
pads are not replaced when needed.
GS430 front brake only—
The high brake performance is achieved by proper wear of
brake pads and discs. As a result, the brake discs may wear
earlier than the ones on the conventional brake system.
When brake pads are replaced, brake disc thickness is
required to be measured.
It is dangerous to continue driving when brake pads and discs
have exceeded the wear limit.
ELECTRIC POWER STEERING SYSTEM
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. 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 581.

STARTING AND DRIVING
439
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.
CAUTION
If the electric power steering system warning light
comes on, take your vehicle to your Lexus dealer as
soon as possible. In this case, more effort is required
for the steering wheel to turn than usual. Drive your
vehicle while firmly gripping the steering wheel.

STARTING AND DRIVING
440
TIRE PRESSURE WARNINGSYSTEM
The tire pressure warning system warns you that the tire
inflation pressure is low.
The tire pressure warning syst em is not a substitute for
checking n ormal tire inflation pressure. Check the tire inflation
pressure with a tire pressure gauge regularly.
CAUTION
The warning system may not activate immediately if
bursts or sudden air leakage should occur.
G31003
 Tire pressure warning light
The tire pressure warning light comes on when the engine
switch “IG−ON” mode is selected, and goes off after a few
seconds. This means the tire pressure warning light is
operating properly. If the tire inflation pressure becomes low,
the light comes on again. At this time, the master warning light
comes on and the message “LOW TIRE” appears on the
multi−information display.
In this case, adjusting the tire inflation pressure will turn off the
light after a few minutes. If the light blinks, the tire pressure
warning system is not working properly. At this time, the
master warning light comes on and the message “CHECK
SYSTEM” appears on the multi −information display.

STARTING AND DRIVING
441
Display
Indicator
statusMeaningsDo this
Tire pressure
warning lightONTire inflation
pressure is
lowAdjust the tireinflation
pressure
Multi
information
displayLOW TIRE
(PRESSURE)
Tire pressure
warning lightBlinkingTire pressure
warning
system
malfunctionHave the
system
checked at
your Lexus
dealer
Multi
information
displayCHECK
(TIRE
PRES-
SURE)
SYSTEM
CAUTION
If the tire pressure warning light comes on, be sure to
observe the following precautions. Failure to do so
could cause loss of vehicle control and result in death
or serious injury.
Vehicles with runflat tires:
 Decelerate to the lowest appropriate speed as soon
as possible. Do not drive over 90 km/h (55 mph).
 Check and adjust the tire inflation pressure
immediately.
 If the tire pressure warning light comes on even after
tire inflation pressure adjustment, it is probable that
you have a flat tire. Have the tire replaced by the
nearest Lexus dealer.
 Avoid abrupt maneuvering and braking. If the vehicle
tires deteriorate, you could lose control of the
steering wheel or the brakes.
Vehicles with standard tires:
 Stop your vehicle in a safe place as soon as possible.
Adjust the tire inflation pressure immediately.
 If the tire pressure warning light comes on even after
tire inflation pressure adjustment, it is probable that
you have a flat tire. Check the tires. If the tire is flat,
change to the spare tire and have the flat tire repaired
by the nearest Lexus dealer.
 Avoid abrupt maneuvering and braking. If the vehicle
tires deteriorate, you could lose control of the
steering wheel or the brakes.

STARTING AND DRIVING
442The tire pressure warning light may turn on due to natural
causes such as natural air l
eaks or tire inflation pressure
changes caused by temperature. In this case, adjusting the
tire inflation pressure will turn off the light after a few minutes.
Pushing the tire pressure warning reset switch should not turn
off the tire pressure warning light. Adjusting the tire inflation
pressure will turn off the light.
The compact spare tire is not equipped with the tire pressure
warning valve and transmitter. If a tire goes flat, the warning
light will not turn off even though the flat tire is replaced with the
spare tire. Replace the spare tire with the repaired tire and
adjust the proper tire inflation pressure. The tire pressure
warning light will turn off after a few minutes.
CAUTION
Each tire, including the spare (if provided), should be
checked m onthly when cold and inflated to the inflation
pressure recommended by the vehicle manufacturer on
the vehicle placard or tire inflation pressure label (tire
and load information label). (If your vehicle has tires of
a different size than the size indicated on the vehicle
placard or tire inflation pressure label (tire and load
information label), you should determine the proper tire
inflation pressure for those tires.)
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring system
(TPMS–tire pressure warning system) that illuminates a
low tire pressure telltale (tire pressure warning light)
when one or more of your tires is significantly
underinflated. Accordingly, when the low tire pressure
telltale (tire pressure warning light) illuminates, you
should stop and check your tires as soon as possible,
and inflate them to the proper pressure. Driving on a
significantly underinflated tire causes the tire to
overheat and can lead to tire failure. Underinflation
also reduces fuel efficiency and tire tread life, and may
affect the vehicle’s handling and stopping ability.

STARTING AND DRIVING
443
Please note that the TPMS (tire pressure warning
system) is not a substitute for proper tire maintenance,
and it is the driver’s responsibility to maintain correct
tire pressure, even if underinflation has not reached
the level to trigger illumination of the TPMS low tire
pressure telltale (tire pressure warning light).NOTICE
 Do not use liquid sealants for a flat tire as tire
pressure warning valve and transmitter will be
damaged.
 When the tires must be repaired or replaced, have
them repaired or replaced by your Lexus dealer or an
authorized tire dealer. The tire pressure warning
valves and transmitters will be affected by the
installation or removal of tires.

STARTING AND DRIVING
444If the tire pressure warning light blinks...
G31048
If the tire pressure warning light blinks when the engine
switch “IGON” mode is selected, the tire pressure
warning system is not working properly.
The system will be disabled in the following conditions:
(When the condition becomes normal, the system will work
properly.)

If tires not equipped with tire pressure warning valves and
transmitters are used.
 If the ID code on the tire pressure warning valves and
transmitters is not registered.
 If electronic devices or facilities using similar radio wave
frequencies are nearby.
 If a radio set at similar frequencies is in use in the vehicle. 
If a window tint that affects the radio wave signals is
installed.
 If the tire pressure warning select switch is set to a dif ferent
tire setting.
 If there is a lot of snow or ice on the vehicle, in particular
around the wheels or wheel housings.
 If non− genuine Lexus wheels are used.
 If tire chains are used.
 If the tire inflation pressure is more than 500 kPa (5.1
kgf/cm
2 or bar, 73 psi).
If the tire pressure warning light blinks frequently when the
engine switch “IG −ON” mode is selected, have it checked by
your Lexus dealer.
Even if you use genuine wheels, the tire pressure warning
system may not work properly with some types of tires.
Pushing the tire pressure warning reset switch should not turn
off the tire pressure warning light.

STARTING AND DRIVING
445
For vehicles sold in U.S.A.
This device complies with
Part 15 of the FCC Rules.
Operation is subject to the following two conditions: (1)
This device may not cause harmful interference, and (2)
this device must accept any interference received,
including interference that may cause undesired
operation.
NOTICE:
This equipment has been tested and found to comply
with the limits for a Class B digital device, pursuant to
Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection against harmful
interference in a residential installation. This equipment
generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with
the instructions, may cause harmful interference to
radio communications. However, there is no guarantee
that interference will not occur in a particular
installation. If this equipment does cause harmful
interference to radio or television reception, which can
be determined by turning the equipment off and on, the
user is encouraged to try to correct the interference by
one or more of the following measures:
 Reorient or relocate the receiving antenna.
 Increase the separation between the equipment and
receiver.
Connect the equipment into an outlet on a circuit
different from that to which the receiver is connected.
 Consult the dealer or an experienced radio / TV
technician for help.
FCC WARNING:
Changes or modifications not expressly approved
by the party responsible for compliance could void
the user’s authority to operate the equipment.
For vehicles sold in Canada
Operation is subject to the following two conditions: (1)
this device may not cause interference, and (2) this
device must accept any interference, including
interference that may cause undesired operation of the
device.

STARTING AND DRIVING
446
Replacing tires and wheels
When replacing the tires and wheels, be sure to install tire
pressure warning valves and transmitters. ID codes on the tire
pressure warning valves and transmitters are registered on the
tire pressure warning ECU. When replacing a tire pressure
warning valve and transmitter, it is necessar y to register the ID
code of tire pressure warning valve and transmitter. Have the
ID code registered by your Lexus dealer.
If the ID code is not registered, the system will not work
properly. After about 1 hour, the tire pressure warning light
blinks to indicate a system malfunction.
NOTICE
When the tires or tire pressure warning valves and
transmitters must be replaced, have them replaced by
your Lexus dealer. The tire pressure warning valves
and transmitters will be affected by the installation or
removal of tires.
Tire pressure warning reset switch
G31004a
When initializing the system, the present tire inflation pressure
is stored as standard. The tire pressure warning system
determines decreased air pressure by comparing the present
and the standard tire inflation pressures. When you change
the set tire inflation pressure, it is necessary to initialize the tire
pressure warning system.
 When rotating the tires on vehicles differing with front and
rear tire inflation pressures.
 When changing the tire inflation pressure by changing
traveling speed or load weight, etc.
 When changing the tire size.