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

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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.

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Avoid racing the engine.
 Do not pushstart or pullstart your vehicle.
 Do not turn off the engine while the vehicle is moving.
 Keep your engine in good running order.
Malfunctions in the engine electrical system,
electronic ignition system or fuel system could cause
an extremely high threeway catalytic converter
temperature.
 If the engine becomes difficult to start or stalls
frequently, take your vehicle in for a checkup as
soon as possible. Remember, your Lexus dealer
knows your vehicle and its threeway catalytic
converter system best.
 To ensure that the threeway catalytic converter and
the entire emission control system operate properly,
your vehicle must receive the periodic inspections
required by the Lexus Maintenance Schedule. For
scheduled maintenance information, refer to the
“Owner’s Manual Supplement / Scheduled
Maintenance”.
ENGINE EXHAUST CAUTION
CAUTION
Avoid inhaling the engine exhaust. It contains
carbon monoxide, which is a colorless and odorless
gas. It can cause unconsciousness or even death.
 Make sure the exhaust system has no holes or loose
connections. The system should be checked from
time to time. If you hit something, or notice a change
in the sound of the exhaust, have the system checked
immediately.
 Do not run the engine in a garage or enclosed area
except for the time needed to drive the vehicle in or
out. The exhaust gases cannot escape, making this
a particularly dangerous situation.
 Do not remain for a long time in a parked vehicle with
the engine running. If it is unavoidable, however, do
so only in an unconfined area and adjust the heating
or cooling system to force outside air into the vehicle.
 Keep the trunk lid closed while driving. An open or
unsealed trunk lid may cause exhaust gases to be
drawn into the vehicle.

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To allow proper operation of your vehicle’s
ventilation system, keep the inlet grilles in front of the
windshield clear of snow, leaves, or other
obstructions.
 If you smell exhaust fumes in the vehicle, drive with
the windows open and the trunk lid closed. Have the
cause immediately located and corrected.OPERATING THE ENGINE SWITCH
G31030
 1
Electronic key 2Engine switch
3Automatic transmission selector lever
4Brake pedal

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Engine switch
G31031
By pushing the engine switch with an electronic key in
possession, you can select “ACC”, “IGON” or “OFF”
mode and start or stop the engine. (For details, see
“Selecting the mode” on page 344 and “Starting the engine” on
page 350 and “Stopping the engine” on page 351.)
When an electronic key is in the vehicle, it is automatically
detected and checked if it corresponds to the registered ID
code for the vehicle, thereby allowing engine operation and
mode selection.
Press the engine switch slowly and firmly. Quick operation
may not activate the desired mode. In the following conditions, the system malfunctions. Contact
your Lexus dealer.

If the engine switch is not illuminated when the clearance
lights are turned on.
 If the engine switch indicator light flashes amber.
 If the switch movement seems unusual.
If, in an emergency, you must turn the engine off while the
vehicle is moving, press the engine switch for more than 3
seconds. At this time, “ACC” mode is selected.
CAUTION
 Do not press the engine switch during driving, except
in an emergency situation.
 If you leave your vehicle in hot weather, the switch
surface may get hot. Take care not to get burned.

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NOTICE
Observe the following instructions, or the engine switch
may not work properly.
 The switch should be operated with your clean finger.
Do not use an oily or dirty finger.
 Be careful not to spill water or other liquid on the
switch.
Do not modify the engine switch without consulting
your Lexus dealer. Doing so may cause system
problem.
Selecting the mode
G31076
“OFF” mode
“ACC” mode
“IG−ON” mode
To select “ACC”, “IGON” or “OFF” mode, press the
engine switch while carrying an electronic key with the
selector lever in the “P” position, and the brake pedal not
depressed.
Each time you press the engine switch, the mode changes in
order of “OFF”, “ACC”, “IG−ON” mode then back to “OFF”
mode.
To start the engine in each mode, push the engine switch while
the brake pedal is depressed. For details, see “Starting the
engine” on page 350.

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“ACC” mode
G31033
This mode allows some accessories to be operable such
as the radio, even if the engine is not running. An amber
indicator light turns on at the engine switch.
To select the “ACC” mode from “OFF” mode, push the engine
switch once without depressing the brake pedal. The engine
immobilizer is disabled and the security indicator light goes
out. (For details, see “Engine immobilizer” on page 11.)
If you cycle once through all the modes (“OFF”, “ACC”,
“IG−ON”) with the driver’s door closed, the second time you
select the “ACC” mode, the above message will appear for a
few seconds.
If the vehicle is left in “ACC” mode for about an hour, the engine
switch is automatically off.
If the driver’s door is opened with the transmission in “P”, a
buzzer will remind you in “ACC” mode.
“IGON” mode
G31034
“IGON” mode has two conditions: all gauges, meters
and accessories on and the engine is not running, or
engine running.
To select the “IG
−ON” mode while the engine is not running:
 From “OFF” mode—push the engine switch twice without
depressing the brake pedal.
 From “ACC” mode—push the engine switch once without
depressing the brake pedal.
The engine switch indicator light will be illuminated amber if the
engine is not running, and will turn off when the engine is
running.

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346If you push the engine switch while the brake pedal is
depressed with the transmission not in “P” or “N”, “IG
−ON”
mode is selected with the engine not running.
It is not a malfunction if the needles on all meters and gauges
move slightly when selected in “IG− ON” mode.
NOTICE
Do not leave the engine switch in “IGON” mode while
the engine is not running. The battery will be
discharged.
“OFF” mode
G31032
This mode turns the engine and all accessories off.
To select the “OFF” mode from “IG− ON” mode:
 If the engine is not running, push the engine switch once
while the brake pedal is not depressed.
 If the engine is running, push the engine switch once
regardless of brake pedal position while the vehicle is
completely stopped.
To select the “OFF” mode from “ACC” mode, push the engine
switch twice while the brake pedal is not depressed.
The engine immobilizer is automatically set, the security
indicator light blinks and the engine switch indicator light is
turned off. (For details, see “Engine immobilizer” on page 11.)
The steering wheel can be locked only in this mode.

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Steering lock
The steering wheel is locked in “OFF” mode.
When the steering lock is activated, you may hear a sound
coming from the steering column, it is not a malfunction. If you
select the “OFF” mode while the driver’s door is open, the
steering wheel is not locked until the driver’s door is closed.
If you select the mode other than “OFF” or start the engine, the
steering lock is disabled.
If there is trouble somewhere in the steering lock system, either
of the following warning messages will appear on the
multi−information display.
 S/T IS NOT UNLOCKED
 CHECK S/T LOCK
G31045
When pushing the engine switch while the brake pedal is
depressed, the steering lock is not unlocked if load is
applied to the steering wheel, and the above message
appears.
The engine will not start. At this time, the master warning light
comes on and the engine switch indicator light blinks green.