2006 Lexus GS430 check engine light

STARTING AND DRIVING
412
G13075
If the system malfunction is detected when dynamic radar
cruise control is in the “RADAR READY” mode or
operating, the above message appears.
If this message appears, stop your vehicle in a safe place, turn
the engine switch off, and then restart it to reset the system.
If the setting still cannot be made or the same message
appears again, the system might have malfunctioned.
Although it is no problem to continue driving, contact your
Lexus dealer.
NOTICE
While you are cruising with the dynamic radar cruise
control on, if the master warning light comes on, the
“CRUISE” indicator light flashes, “CHECK CRUISE
SYSTEM” appears on the multiinformation display and
the warning tone sounds, turn the engine switch off and
then on again. If the function is cancelled again after
setting or if settings cannot be made, the dynamic radar
cruise control system may be malfunctioning.
Although it is no problem to continue driving, have your
vehicle checked by your Lexus dealer.
Conventional (fixed speed) cruise control
mode
This mode allows you to cruise at a desired speed over
about 45 km/h (28 mph) with your foot off the accelerator
pedal.
Cruising speed can be maintained, although a slight speed
change may occur when driving up or down a gradient, within
the limits of engine performance. On steeper hills, the speed
will change more radically so it is better to drive without cruise
control.
When cruise control is on, the driving pattern of the automatic
transmission is fixed in the normal mode, regardless of the
position of the selector switch.

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TRACTION CONTROL SYSTEM
The traction control system automatically helps prevent
the spinning of rear wheels when the vehicle is started or
accelerated on slippery road surfaces.
When the engine switch is selected in “IG−ON” mode, the
system automatically turns on.
CAUTION
Under certain slippery road conditions, full traction of
the vehicle and power against rear wheels cannot be
maintained, even though the traction control system is
in operation. Do not drive the vehicle under any speed
or maneuvering conditions which may cause the
vehicle to lose traction control. In situations where the
road surface is covered with ice or snow, your vehicle
should be fitted with snow tires or tire chains. Always
drive at an appropriate and cautious speed for the
present road conditions.
G31038
 Slip indicator light
Leave the system on during the ordinary driving so that it
can operate when needed.
You may hear a sound in the engine compartment for a few
seconds just after the vehicle begins to move. This means that
the traction control system is in the self −check mode, but does
not indicate a malfunction.
When the traction control system is operating, the following
conditions occur:
 The system controls the spinning of the rear wheels. At this
time, the slip indicator light blinks.
 You may feel vibration or noise in your vehicle, caused by
operation of the brakes. This indicates the system is
functioning properly.
GS430—The slip indicator light comes on when the engine
switch is selected in “IG− ON” mode. The light goes off when
the engine is started.

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Traction control system failure warning
G31039
 1GS430 2GS300
If the traction 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 traction control system, vehicle
stability control system and hill− start assist 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.
VEHICLE STABILITY CONTROL SYSTEM
The vehicle stability control system helps provide
comprehensive control of the systems such as antilock
brake system, traction control, engine control, etc. This
system automatically controls the brakes and engine to
help prevent the vehicle from skidding when cornering on
a slippery road surface or operating steering wheel
abruptly.
This system activates when the vehicle speed is about more
than 15 km/h (9 mph).
You may hear a sound in the engine compartment for a few
seconds just after the vehicle begins to move. This means that
the system is in the self− check mode, but does not indicate a
malfunction.

STARTING AND DRIVING
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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)

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VEHICLE DYNAMICS
INTEGRATED MANAGEMENT (GS430 only)
Vehicle Dynamics Integrated Management (VDIM) helps
manage control for vehicle stability control system,
antilock brake system, brake assist system, traction
control system, engine output control, hillstart assist
control system and also manages variable gear ratio
steering system and electric power steering system.
In order to control sudden steering wheel operation and
the sideslip on slippery road surfaces, this system
provides excellent vehicle stability by automatically
controlling the brake, engine output and front wheel
angle.
The state of the tires will affect the performance of the vehicle
dynamics integrated management system. Be sure to check
the following:
 Are tires of specified size installed?
 Are tires of identical type installed?
 Do the tires have stipulated tire pressure?
 Are the tires worn?
A problem with the tires or modified suspension systems will
have an adverse effect on the system and may cause a
malfunction, so be careful. When the slip indicator light comes on, and the message
“CHECK ECB” appears on the multi
−information display, the
vehicle dynamics integrated management does not operate.
Have your vehicle checked by your Lexus dealer as soon as
possible.
In addition, when the master warning light comes on, and the
message “CHECK VGRS” or “CHECK P/S” appears on the
multi−information display, the system will not be temporarily
functioning. Although it is no problem in driving as usual, have
your vehicle checked by your Lexus dealer as soon as
possible.
CAUTION
Do not overestimate the vehicle dynamics integrated
management. Even when this management is
functional, there is a limit to vehicle stability, and
irresponsible driving may lead to an accident. When
driving, you should always pay attention to your speed
and keep a safe distance between your vehicle and the
vehicle in front.

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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 78 or 430.
BRAKE PAD WEAR LIMIT
INDICATORS
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.

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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.

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To initialize the system, perform the following:
1. Park
the vehicle at a safe place and apply the parking brake.
Stop the engine.
2. Adjust the pressure of all the installed tires to the specified
level. (See “Tires and wheels” on pages 534 and 537.)
3. Start the engine.
4. Push and hold the reset switch until the low tire pressure
warning light blinks three times, and the message
“PRESSURE INITIAL” appears on the multi− information
display.
Do not turn the engine off for about 20 minutes until
initialization is complete.
G31007
When initializing the system, make sure the low tire pressure
warning light blinks three times and the message “PRESSURE
INITIAL” appears on the multi− information display. If the
warning light does not blink three times and the message does
not appear on the multi−information display, initialization failed
and the tire pressure warning system will not function properly.
In this case, initialize the system again.
Do not push the reset switch without adjusting the tire inflation
pressure to the specified level. Otherwise, the low tire
pressure warning light may not come on even if the tire inflation
pressure is low, or it may come on when the tire inflation
pressure is actually normal.
If you push the reset switch while the vehicle is moving,
initialization is not performed.
If the low tire pressure warning light does not blink and the
message does not appear on the multi−information display
when you push and hold the reset switch, have the tire
pressure warning system checked at your Lexus dealer.