2006 Lexus GS430 check engine light

KEYS AND DOORS
12If the electronic key battery is discharged, the entry function
and wireless remote control cannot be used. Use the
mechanical key integrated into
the electronic key by inserting
it in the door keyhole to lock or unlock doors and into the trunk
lid keyhole to unlock the trunk lid. To start the engine, see
“Starting the engine when the electronic key battery is
discharged” on page 357. In order to activate the entry function
and wireless remote control, the battery should be replaced.
For details, see “Replacing the battery” on page 34.
(a) Engine immobilizer
G11009
The engine immobilizer is a theft prevention function.
When you enter the vehicle carrying an electronic key and
press the engine switch, the electronic code in the key is
automatically checked to determine whether it
corresponds to the registered ID code for the vehicle. If
the ID code is verified, you can start the engine.
The system is automatically set when the engine switch is off.
The indicator light will start flashing to show the system is set.

KEYS AND DOORS
23
UNLOCKING THE DOOR(S) WITH ENTRY FUNCTION
G11032
When you take hold the back side of the outside door
handle on the driver’s door carrying an electronic key, the
driver’s door will be unlocked. When you take hold the
back
side of the outside door handle except on the driver’s
door, carrying an electronic key, all the doors will be
unlocked. At this time, two beeps will sound and turn
signal lights flash twice.
When you get close to your vehicle (about 1 m (3 ft.) from each
outside door handle), and are carrying the electronic key, the
electronic code emitted from the key is automatically checked
to determine if it corresponds to the registered ID code for the
vehicle. After this, the outer foot lights come on. (For outer foot
lights, see “Outer foot lights” on page 212.)
You can select the doors to be unlocked. For details, see
“Changing the doors to be unlocked” on page 24. When the door(s) is(are) unloc
ked, the interior lights come on
for 15 seconds if the interior light switch is in the “DOOR”
position. However, the interior lights go out when you push the
power door lock switch in the lock position or select the engine
switch in “ACC” or “IG− ON” mode. For further information, see
“Interior lights” on page 100.
You have 30 seconds to open a door after operating the
unlocking function. If a door is not opened by then, all the doors
will be automatically locked again.
INFORMATION
 When unlocking the door(s), be sure to take hold of
the back side of the outside door handle firmly as
shown in the illustration. Taking hold of the handle
with a gloved hand might cause a delay in unlocking
or may not unlock.
 When you take hold of the handle to unlock the
door(s), be sure to confirm that the door(s) has(have)
been unlocked. If the turn signal lights flash twice,
two beeps sound outside the vehicle, the doors are
unlocked. At this time, you can pull the outside door
handle to open the door. If you quickly move closer
to the vehicle or pull the outside door handle quickly,
the doors might not unlock. If you cannot open the
door by pulling the outside door handle at this time,
push it back to the original position and then pull it
out again.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
76IF THIS INDICATOR OR
BUZZER COMES ON ...
DO THIS.
(p)Key reminder
buzzerTurn off the engine
switch.
(a) Brake System Warning Light (red) and Buzzer
This light comes on in the following cases when the engine
switch is selected in “IG −ON” mode.
 When the parking brake is applied ...
GS430—This light comes on fo r a few seconds when the
engine is started even after the parking brake is released.
GS300—This light comes on fo r a few seconds when the
engine switch is selected in “IG −ON” mode even after the
parking brake is released.
If you drive your vehicle without releasing the parking brake,
the buzzer sounds and the message “PARK BRAKE” appears
on the multi −information display.
 When the brake fluid level is low ...
CAUTION
It is dangerous to continue driving normally when the
brake fluid level is low.
Have your vehicle checked at your Lexus dealer in the
following case:
The light does not come on even if the parking brake is
applied when the engine is started.
 The light does not come on even if the engine is started with
the parking brake released.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
77
A warning light turning on briefly during operation does not
indicate a problem.
CAUTION
If either of the following conditions occurs, immediately
stop your
vehicle at a safe place and contact your Lexus
dealer.
 The light does not turn off even after the parking
brake is released while the engine is running.
In this case, the brakes may not work properly and
your stopping distance will become longer. Depress
the brake pedal firmly and bring the vehicle to an
immediate stop.
 The brake system warning light remains on together
with the “ABS” warning light.
In this case, not only the antilock brake system will
fail but also the vehicle will become extremely
unstable during braking.
GS430 only—Any of the following conditions may occur,
but do not indicate the 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
warning light and buzzer. It is normal if the light turns off and
the buzzer stops sounding after a few seconds. 
You may hear a small sound in the engine compartment
after the engine is started or the brake pedal is depressed
repeatedly. This is a pump pulsating sound of the brake
system, and it is not a malfunction.
(b) Brake System Warning Light (yellow)
The light comes on when the engine switch is selected in
“IG−ON” mode.
GS430—If the engine is started, and the traction control
system, vehicle stability control system and hill −start assist
control system work properly, the light turns off after a few
seconds. Thereafter, if any part of the system malfunctions,
the light comes on again.
GS300—If the engine switch is selected in “IG −ON” mode, and
the traction control system, vehicle stability control system and
hill −start assist control system work properly, the light turns off
after a few seconds. Thereafter, if any part of the system
malfunctions, the light comes on again.
Although it is no problem to continue driving, have your vehicle
checked by your Lexus dealer as soon as possible.
(c) Driver’s Seat Belt Reminder Light and Buzzer
The light and buzzer act as a reminder to have the driver buckle
up the seat belt.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
79
(f) Charging System Warning Light
This warning light comes on when the engine switch is
selected in “IG−ON” mode, and goes off when the engine is
started.
When there are problems in the charging system while the
engine is running, the warning light comes on.
NOTICE
When the charging system warning light comes on
while the engine is running, malfunctions such as the
engine drive belt being broken may have occurred. If
the warning light comes on, immediately stop the
vehicle in a safe place and contact your Lexus dealer.
(g) Malfunction Indicator Lamp
This lamp comes on when the engine switch is selected in
“IGON” mode and goes off after the engine starts. This
means that the warning light system is operating properly.
If the lamp remains on, or the lamp comes on while
driving, first check the followings:
 Empty fuel tank
If the fuel tank is empty, refuel immediately.
 Loose fuel tank cap
If the fuel tank cap is loose, securely tighten it.
These cases are temporary malfunctions. The malfunction
indicator lamp will go off after taking several driving trips.
If the lamp does not go off even after several trips, contact your
Lexus dealer as soon as possible.
If the fuel tank is not empty or the fuel tank cap is not
loose...
 There is a problem somewhere in the engine, emission
control system, electronic throttle control system, automatic
transmission electrical system or warning light system itself.
Contact your Lexus dealer as soon as possible to service the
vehicle.
If this lamp comes on and engine speed does not increase
when the accelerator pedal is depressed, there may be a
problem somewhere in the electronic throttle control system.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
80At 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 engine switch is
selected in “ACC” or “OFF” mode.
Emissions inspection and maintenance (I/M) programs
Your vehicle may not pass a state emission inspection if the
malfunction indicator lamp remains on. Contact your Lexus
dealer to check your vehicle’s emission control system and
OBD (On
−Board Diagnostics) system before taking your
vehicle for the inspection.
For details, see “Emissions inspection and maintenance (I/M)
programs” on page 505.
(h) Master Warning Light
If any system malfunctions, this warning light comes on or
flashes together with a warning tone, and a warning message
appears on the multi−information display. When the cause of
the problem is eliminated, the warning tone and message on
the display will turn off.
(i) ”ABS” Warning Light
The light comes on when the engine switch is selected in
“IG−ON” mode.
GS430—If the anti−lock brake system and the brake assist
system work properly, the light turns of f in a few seconds after
the engine is started. Thereafter, if either system malfunctions,
the light comes on again.
GS300—If the anti−lock brake system and the brake assist
system work properly, the light turns of f in a few seconds after
the engine switch is selected in “IG−ON” mode. Thereafter, if
either system malfunctions, the light comes on again.
When the “ABS” warning light is on, the anti− lock brake system
and the brake assist system do not operate, but the brake
system still operates conventionally.
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 the engine switch is
selected in “IG −ON” mode.
 The light remains on after the engine is started (GS430), or
remains on 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.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
81
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.
(j) Open Door Warning Light
This light remains on until all the doors are completely closed.
(k) Adaptive Front Lighting System Off
Indicator Light
This light comes on when yo u turn off the Adaptive Front
Lighting System (AFS) by pushing the “AFS OFF” switch.
If there is a problem somewhere in the Adaptive Front Lighting
System (AFS) or automatic headlight leveling system, the light
flashes. At this time, both systems do not operate properly.
Although it is no problem to continue driving, have your vehicle
checked by your Lexus dealer as soon as possible.
(l) Tire pressure warning light
This light comes on when the engine switch is selected in
“IG−ON” mode. If the tire pressure warning system works
properly and tire inflation pressure is appropriate, the light
goes off after a few seconds.
This light comes on or flashes in the following cases when the
engine switch is selected in “IG −ON” mode.
 When the low tire inflation pressure is detected while
driving...
If any tire has low inflation pressure, the light comes on.
The light goes off after the tire inflation pressure is adjusted
to a specified level.
 When initializing the system...
If initialization is completed, the light blinks three times.
 When the system malfunctions...
If the system malfunctions, the light blinks.

GAUGES, METERS AND SERVICE REMINDER INDICATORS
82Although it is no problem to continue driving, have your
vehicle
checked by your Lexus dealer as soon as possible.
(m) 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.
The warning light turning on while racing the engine for a long
time may not indicate malfunction. To turn off the light, restart
the engine and start 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.
(n) PreCollision System Warning Light
The light warns that there is a problem somewhere in the
pre−collision system.
The light comes on when the engine switch is selected in
“IG−ON” mode. If the system works properly, the light goes off
after a few seconds.
If the light does not come on when the engine switch is selected
in “IG−ON” mode, have your vehicle checked by your Lexus
dealer.
(o) Low Fuel Level Warning Light
This light comes on when the fuel level in the tank becomes
very low. Fill the tank as soon as possible.
On inclines or curves, due to the movement of fuel in the tank,
the low fuel level warning light may come on earlier than usual.
(p) Key Reminder Buzzer
This buzzer acts as a reminder to turn off the engine when you
bring out the electronic key from the vehicle with the engine
switch in “IG−ON” or “ACC” mode.