2018 Lexus GS450h warning light

4077-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
7
When trouble arises
*: Driver’s seat belt buzzer:The driver’s seat belt buzzer sounds to alert the driver that his or her seat belt is not
fastened. Once the power switch is turned to ON mode, the buzzer sounds for 6 sec-
onds. If the vehicle reaches a speed of 12 mph (20 km/h), the buzzer sounds once. If
the seat belt is still unfastened after 24 seconds, the buzzer will sound intermittently
for 10 seconds. Then, if the se at belt is still unfastened, the buzzer will sound in a differ-
ent tone for 20 more seconds.
Front passenger’s seat belt buzzer:
The front passenger’s seat belt buzzer soun ds to alert the front passenger that his or
her seat belt is not fastened. The buzzer so unds once if the vehicle reaches a speed of
12 mph (20 km/h). If the seat belt is still unfastened after 24 se conds, the buzzer will
sound intermittently for 10 se conds. Then, if the seat belt is still unfastened, the buzzer
will sound in a different to ne for 20 more seconds.
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors, side
impact sensors (front door), side impact se nsors (front), side impact sensors (rear),
driver’s seat position sensor, driver’s seat belt buckle switch, front passenger occupant
classification system, “AIR BAG ON” indicat or light, “AIR BAG OFF” indicator light,
front passenger’s seat belt buckle switch, seat belt pretensioner assemblies, airbags,
interconnecting wiring and power sources. (→P. 37)
■Front passenger detection sensor, seat belt reminder and warning buzzer
If luggage is placed on the front passenger seat, the front passenger detection sensor
may cause the warning light to flash and the warning buzzer to sound even if a passenger
is not sitting in the seat.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fu el tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving trips.
If the light does not go off even after severa l trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insu fficient or the voltage temporarily drops,
the electric power steering system warning light may come on and the warning buzzer
may sound.
(If equipped)
LKA warning light The warning light comes on and a warning message is displayed to
indicate that the LKA (Lane-Keepin g Assist) system is not available
temporarily or has detected a malfunction.
→ P. 421, 422
Warning lightWarning light/Details/Actions

4087-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Initializing the tire
pressure warning system will not turn off the tire pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air
leaks and tire inflation pressure changes caus ed by temperature. In this case, adjusting
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 with a tire pressure warning valve and transmit-
ter. If a tire goes flat, the tire pressure warning light will not turn off even though the flat
tire has been replaced with the spare tire.
■Conditions that the tire pressure wa rning system may not function properly
→ P. 370
■If the tire pressure warning light freque ntly comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the
power switch is turned to ON mode, ha ve it checked by your Lexus dealer.
■Warning buzzer
In some cases, the buzzer may not be heard because of noisy place or an audio sound.
■Customization
The vehicle speed linked seat belt reminder buzzer can be disabled.
(Customizable features: →P. 494)
WARNING
■If both the ABS and the brake sy stem warning lights remain on
Stop your vehicle in a safe place immediat ely and contact your Lexus dealer. The vehi-
cle will become extremely unstable during br aking, and the ABS system may fail, which
could cause an accident resultin g in death or serious injury.
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
If the steering wheel becomes heavier than usual when operating, hold firmly and oper-
ate using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precaution s. Failure to do so could cause a loss of
vehicle control and result in death or serious injury.
●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 adjust-
ment, it is probable that you have a flat tire . Check the tires. If a tire is flat, change it
with 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.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.

4097-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
7
When trouble arises
WARNING
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold and
inflated to the inflation pressure recomm ended 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 in formation label], you should determine the
proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle ha s been equipped with a tire pressure moni-
toring system (TPMS-tire pressure warning system) that illuminates a low tire pressure
telltale (tire pressure warning light) when on e or more of your tires is significantly
under-inflated. Accordingly, when the low ti re 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 si gnificantly 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 wa rning system) is not a substitute for proper
tire maintenance, and it is th e driver’s responsibility to ma intain correct tire pressure,
even if under-inflation has not reached the le vel to trigger illumination of the TPMS low
tire pressure telltale (tir e pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system) mal-
function indicator to indicate when the system is not operating properly. The TPMS
(tire pressure warning system) malfunction indi cator is combined with the low tire pres-
sure telltale (tire pressure warning light). When the system detects a malfunction, the
telltale will flash for approximately one mi nute and then remain continuously illumi-
nated. This sequence will cont inue upon subsequent vehicle start-ups as long as the
malfunction exists. When the malfunction in dicator is illuminated, the system may not
be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfun ctions may occur for a variety of reasons,
including the installation of replacement or alternate tires or wheels on the vehicle that
prevent the TPMS (tire pressure warning system) from functioning properly. Always
check the TPMS (tire pressure warning system) malfunction telltale 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 pressu re warning system) to continue to function
properly.
NOTICE
■To ensure the tire pressure warning system operates properly
Do not install tires with differ ent specifications or markers, as the tire pressure warning
system may not operate properly.

410
GS450h_OM_OM30G62U_(U)
7-2. Steps to take in an emergency
If a warning message is displayed
Master warning light
The master warning light also comes on or flashes in order to indicate that a message
is currently being displayed on the multi-information display.
Multi-information display
If any of the warning light comes on ag ain after the following actions have been
performed, contact your Lexus dealer.
If a warning is shown on the multi-info rmation display, stay calm and perform
the following actions:
Except F SPORT modelsF SPORT models
Warning message and warning buzzer list
1
2
Warning messageDetails/Actions
(If equipped)
Indicates that there is a high possibility of a frontal colli-
sion, or that the pre-collision braking function is operat-
ing
At the same time, will appear on the head-up
display.
A buzzer also sounds.
→ Avoid the collision by decelerating using the brakes
or taking other evasive actions.

4257-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
7
When trouble arises
Indicates that the power switch is turned off or turned to
ACCESSORY mode and the driver’s door is opened
while the lights are turned onA buzzer also sounds.
→ Turn the lights off.
Indicates that the moon roof is not fully closed (with the
power switch off, and the driver’s door open)
A buzzer also sounds.
→ Close the moon roof.
Indicates that the windows are not fully closed (with the
power switch off, and the driver’s door open)
A buzzer also sounds.
→ Close all the windows.
Indicates that the windows and the moon roof are not
fully closed (with the power switch off, and the driver’s
door open)
A buzzer also sounds.
→ Close all the windows and the moon roof.
Indicates a malfunction in the brake hold system
A buzzer also sounds.
→ Have the vehicle inspecte d by your Lexus dealer
immediately.
Warning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes)
(Flashes)
(Flashes)

4287-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
Indicates a malfunction in the brake override systemA buzzer also sounds.
→ Have the vehicle inspecte d by your Lexus dealer
immediately.
Indicates that engine oil level is low
This message may ap pear if the vehicle is stopped on a
slope. Move the vehicle to a level surface and check to
see if the message disappears.
A buzzer also sounds.
→ Check the level of engine oil, and add if necessary.
Indicates that the hybrid system has overheated
This message may be disp layed when driving under
severe operating conditions. (For example, when driv-
ing up a long steep hill.)
A buzzer also sounds.
→ Stop and check. ( →P. 461)
Indicates a malfunction in:
• The Automatic High Beam system (if equipped);
• The AFS (Adaptive Front-lighting System) (if equipped); or
• The LED headlight system
A buzzer also sounds.
→ Have the vehicle inspected by your Lexus dealer.
Warning messageDetails/Actions
(Flashes)

4317-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
7
When trouble arises
*: Refer to the separate “Scheduled Maintenance” or “Owner’s Manual Supplement”
for the maintenance interval applicable to your vehicle.
(U.S.A. only)
Indicates that all maintenance according to the driven
distance on the maintenance schedule
* should be per-
formed soon.
Comes on approximately 4500 miles (7200 km)
after the message has been reset.
→ If necessary, perform maintenance.
Indicates that the engine o il and oil filter should be
changed
→ Have the engine oil and oil filter checked and/or
changed by your Lexus dealer. After changing the
engine oil, the oil change system should be reset.
( → P. 355)
(U.S.A. only)
Indicates that all maintenanc e is required to correspond
to the driven distance on the maintenance schedule
*.
Comes on approximately 5000 miles (8000 km)
after the message has been reset. (The message will
not display properly unless the message has been
reset.)
→ Perform the necessary maintenance. Please reset
the message after the maintenance is performed.
(→ P. 344)
(If equipped)
Indicates that the Automati c High Beam switch was
pressed while the low beams were on
→ Turn the high beam headlights on before pressing
the Automatic High Beam switch.
(If equipped)
Indicates that, since the VSC (Vehicle Stability Control)
system was turned off, the pre-collision braking and pre-
collision brake assist are stopped (The pre-collision
warning function will be operational)
→ Turn the VSC on. ( →P. 271)
Warning messageDetails/Actions

4467-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
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.
4
5
WARNING
■Replacing a flat tire
●Do not touch the disc wheels or the area around the brakes immediately after the
vehicle has been driven.
After the vehicle has been driven the disc wheels and the area around the brakes will
be extremely hot. Touching these areas with hands, feet or other body parts while
changing a tire, etc. may result in burns.
●Failure to follow these precautions could cau se the wheel nuts to loosen and the tire
to fall off, resulting in death or serious injury.
• Never use oil or grease on the wheel bolts or wheel nuts. Oil and grease may cause the wheel nuts to be excessively tightened, leading to
bolt or disc wheel damage. In addition, the oil or grease can cause the wheel nuts
to loosen and the wheel may fall off, causing a serious accident. Remove any oil or
grease from the wheel bolts or wheel nuts.
• Have the wheel nuts tightened with a torque wrench to 76 ft•lbf (103 N•m,
10.5 kgf•m) as soon as possible after changing wheels.
• When installing a tire, only use wheel nuts that have been specifically designed for
that wheel.
• If there are any cracks or deformations in the bolt screws, nut threads or bolt holes
of the wheel, have the vehicle inspected by your Lexus dealer.