light Lexus GS450h 2008 Do-it-yourself maintenance / LEXUS 2008 GS450H OWNER'S MANUAL (OM30A96U)

5
When trouble arises
495
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
■Front passenger detection sensor and passenger seat belt reminder
●If luggage is placed on the front passenger seat, the front passenger detection
sensor may cause the warning light to flash, even if a passenger is not sitting in
the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the
warning light may not operate properly.
■SRS warning light
This warning light system monitors the following:
●The airbag sensor assembly
●Front airbag sensors
●The curtain shield and rear side airbag sensors
●The side and curtain shield airbag sensors
●The front passenger occupant classification ECU
●“AIR BAG ON” and “AIR BAG OFF” indicator lights
●The pressure sensor
●The belt tension sensor
●The seat belt buckle switches
●The driver’s seat position sensor
●The inflators
●The warning light
●The interconnecting wiring and power sources
■If the tire pressure warning light comes on after blinking for 1 minute frequently
If the tire pressure warning light comes on after blinking for 1 minute frequently
when the “POWER” switch is turned to ON mode, have it checked by your Lexus
dealer.

496
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch does not turn off the tire pressure warning light.
■If the tire pressure warning system is inoperative
The tire pressure warning 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 regis-
tered in the tire pressure warning computer.
●If the tire pressure warning select switch is set to a different tire setting.
●If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher.
The tire pressure warning system may be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●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 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. (E ven if you use Lexus wheels, the tire
pressure warning system may not work properly with some types of tires.)
●If tire chains are used.
■The tire pressure warning light may turn on due to natural causes
The tire pressure warning light may turn on due to natural causes such as natural air
leaks or tire inflation pressure changes caus ed by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped wi th the tire pressure warning valve and
transmitter. If a tire goes flat, the tire pressure 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.

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When trouble arises
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5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
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 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.
●Vehicles with run-flat tires:
• Decelerate to the lowest appropriate speed as soon as possible. Do not drive over 55 mph (90 km/h).
• 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.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.

498
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
CAUTION
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold
and inflated to the inflation pressure re commended by the vehicle manufacturer on
the vehicle placard or tire inflation pressu re 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 sig-
nificantly under-inflated. Accordingly, when the low tire pressure telltale (tire pres-
sure 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 under-
inflated tire causes the tire to overheat and can lead to tire failure. Under-inflation
also reduces fuel efficiency and tire tread life, and may affect the vehicle’s handling
and stopping ability.
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 under-inflation has not reached the level to trigger illumination of
the TPMS low tire pressure telltale (tire pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system)
malfunction indicator to indicate when th e system is not operating properly. The
TPMS (tire pressure warning system) malfunction indicator is combined with the
low tire pressure telltale (tire pressure warning light). When the system detects a
malfunction, the telltale will flash for approximately one minute and then remain
continuously illuminated. This sequence will continue upon subsequent vehicle
start-ups as long as the malfunction exists . When the malfunction indicator is illumi-
nated, the system may not be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a variety of rea-
sons, including the installation of replacem ent or alternate tires or wheels on the
vehicle that prevent the TPMS (tire pres sure warning system) from functioning
properly. Always check the TPMS (tire pressure warning system) malfunction tell-
tale after replacing one or more tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow the TPMS (tire pressure warning
system) to continue to function properly.

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5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
If a warning message is displayed
Stop the vehicle immediately.A buzzer sounds and a warning message is shown on the multi-informa-
tion display. The following warnings indicate the possibility of damage to
the vehicle that may lead to an acci dent. Immediately stop the vehicle in a
safe place and contact your Lexus dealer.
Wa r n i n g m e s s a g eDetails
(Flashing)
Abnormal engine oil pressure.
The warning light may turn on if the engine oil pres-
sure is too low.
Malfunction in the hybrid system.
If a warning is shown on the multi-information display, stay calm and per-
form the following actions:
Multi-information display
Master warning light
The master warning light also
comes on or flashes in order to
indicate that a message is cur-
rently being displayed on the
multi-information display.
If any of the warning li ght turns on again after pe rforming the following
actions, contact your Lexus dealer.

5
When trouble arises
501
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
Have the vehicle inspected immediately.A buzzer sounds and a warning message is shown on the multi-informa-
tion display. Failing to investigate the cause of the following warnings may
lead to the system operating abnormally and possibly cause an accident.
Have the vehicle inspected by your Lexus dealer immediately.
Wa r n i n g m e s s a g eDetails
Malfunction in the automatic headlight leveling sys-
tem.
Malfunction in the rear lights system.
Malfunction in the tire pressure warning system.
The tire pressure warning light comes on after blink-
ing for 1 minute.
(Flashing)
Malfunction in the steering lock system.

5
When trouble arises
513
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
Have the malfunction repaired immediately.After taking the specified steps to correct the suspected problem, check
that the warning message and light turn off.
InteriorbuzzerExterior buzzerWa r n i n g m e s s a g eDetailsCorrection procedure
Once(Comes on for 10 seconds.)
(Flashing)
The electronic key
is not detected
when attempting
to start the hybrid
system.Confirm the
location of
the elec-
tronic key.
Once3 times
(Flashing)
An open door
other than the
driver’s door is
closed while the
electronic key is
outside the detec-
tion range and the
“POWER” switch
is in ACCES-
SORY or ON
mode.
Confirm the
location of
the elec-
tronic key.

518
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
■The compact spare tire
●The compact spare tire is identified by the label “TEMPORARY USE ONLY”
on the tire sidewall.
Use the compact spare tire temporarily only in an emergency.
●Make sure to check the tire inflatio n pressure of the compact spare tire. 
(  P. 5 5 1 )
■Tr e a d l i f e
The compact spare tire can be used many times, if necessary. It has tread life of up
to 3000 miles (4800 km) depending on road conditions and your driving habits.
When treadwear indicato rs appear on the tire, replace the tire. ( P. 4 3 5 )
■When using the compact spare tire
As the spare tire is not equipped with the tire pressure warning valve and transmit-
ter, low inflation pressure of the spare tire will not be warned. Also, if you replace the
compact spare tire after the tire pressure warning light comes on, the light remains
on.
■ Compact spare tire
The compact tire saves space in your luggage compartment, and its
lighter weight helps to enhance fuel economy and permits easier
installation in case of a flat tire.
The compact spare tire is
designed for temporary emer-
gency use only.

520
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
Replacing a flat tireChock the tires.
Slightly loosen the wheel nuts (one
turn).
STEP1
Flat tireWheel chock positions
FrontLeft-hand sideBehind the rear right-hand side tire
Right-hand sideBehind the rear left-hand side tire
Rear
Left-hand sideIn front of the front right-hand side tire
Right-hand sideIn front of the front left-hand side tire
STEP2

5
When trouble arises
521
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
Turn the tire jack portion “A” by
hand until the notch of the jack is in
contact with the jack point.
Raise the vehicle until the tire is
slightly raised off the ground.
Remove all the wheel nuts and the
tire.
When resting the tire on the
ground, place the tire so that the
wheel design faces up to avoid
scratching the wheel surface.
STEP3
STEP4
STEP5