2018 Lexus GS450h warning light

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6-3. Do-it-yourself maintenance
■Situations in which the tire pressure warning system may not operate properly
●In the following cases, the tire pressure warning system may not operate properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains etc. are equipped.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects th e radio wave signals is installed.
• If there is a lot of snow or ice on the vehi cle, particularly around the wheels or wheel
housings.
• If the tire inflation pressure is extr emely higher than the specified level.
• If wheel without the tire pressure warning valve and transmitter are used.
• If the ID code on the tire pressure warning valves and transmitters is not registered
in the tire pressure warning computer.
●Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large display, air-
port or other facility that generates st rong radio waves or electrical noise
• When carrying a portable radio, cellular phone, cordless phone or other wireless
communication device
If tire position information is not correctly displayed due to the radio wave conditions,
the display may be corrected by driving and changing the radio wave conditions.
●When the vehicle is parked, the time taken for the warning to start or go off could be
extended.
●When tire inflation pressure declines rapidly for example when a tire has burst, the
warning may not function.
■The initialization operation
●Make sure to carry out initialization afte r adjusting the tire inflation pressure.
Also, make sure the tires are cold before carryi ng out initialization or tire inflation pres-
sure adjustment.
●If you have accidentally turned the power switch off during initialization, it is not neces-
sary to manually restart the in itialization again, as initialization will restart automatically
the next time the power switch is turned to ON mode.
●If you accidentally perform initialization when initialization is not necessary, adjust the
tire inflation pressure to the specified leve l when the tires are cold, and conduct initial-
ization again.
■When initialization of the tire pressure warning system has failed
Initialization can be completed in a few minutes. However, in the following cases, the set-
tings have not been recorded and the system will not operate properly. If repeated
attempts to record tire inflation pressure settings are unsuccessful, have the vehicle
inspected by your Lexus dealer.
●The initialization message is not displayed on the multi-information display when per-
forming initialization.
●After carrying out the initializat ion procedure, the tire pressure warning light blinks for 1
minute then stays on after driving for 20 minutes.

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3736-3. Do-it-yourself maintenance
6
Maintenance and care
WARNING
■When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as dangerous han-
dling characteristics, which may lead to an accident resulting in death or serious injury.
●Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix differently constructed tires (radial, bias-belted or bias-ply tires).
●Do not mix summer, all season and snow tires.
●Do not use tires that have be en used on another vehicle.
Do not use tires if you do not know how they were used previously.
■When initializing the tire pressure warning system
Do not initialize tire inflatio n pressure without first adjustin g the tire inflation pressure to
the specified level. Otherwise, the tire pre ssure warning light may not come on even if
the tire inflation pressure is low, or it ma y come on when the tire inflation pressure is
actually normal.
■Caution regarding interference with electronic devices
●Users of any electrical medical device ot her than implantable cardiac pacemakers,
cardiac resynchronization th erapy-pacemakers or implantable cardioverter defibril-
lators should consult the manufacturer of the device for information about its opera-
tion under the influence of radio waves.
Radio waves could have unexpected effects on the operation of such medical
devices.
●People with implantabl e cardiac pacemakers,
cardiac resynchronization therapy-pacemak-
ers or implantable cardioverter defibrillators
should not come within 17.7 in. (450 mm) of
the tire pressure warn ing system initiators.
The radio waves may affect the operation of
such devices.

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6-3. Do-it-yourself maintenance
■After a fuse is replaced
●If the lights do not turn on even after the fuse has been replaced, a bulb may need
replacement. (→P. 391)
●If the replaced fuse blows again, have th e vehicle inspected by your Lexus dealer.
■If there is an overload in a circuit
The fuses are designed to blow, protecting the wiring harness from damage.
■When replacing light bulbs
Lexus recommends that you use genuine Lexus products designed for this vehicle.
Because certain bulbs are connected to circui ts designed to prevent overload, non-gen-
uine parts or parts not designed for this vehicle may be unusable.
WARNING
■To prevent system breakdowns and vehicle fire
Observe the following precautions.
Failure to do so may cause damage to th e vehicle, and possibly a fire or injury.
●Never use a fuse of a higher amperage rating than that indicated, or use any other
object in place of a fuse.
●Always use a genuine Lexus fuse or equivalent.
Never replace a fuse with a wire, even as a temporary fix.
●Do not modify the fuses or fuse boxes.
NOTICE
■Before replacing fuses
Have the cause of electrical overload determined and repaired by your Lexus dealer as
soon as possible.

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6-3. Do-it-yourself maintenance
■LED Lights
The lights other than the front turn signal light (vehicles with single-beam headlights) and
outer foot lights each consist of a number of LEDs. If any of the LEDs burn out, take your
vehicle to your Lexus dealer to have the light replaced.
■Condensation build-up on the inside of the lens
Temporary condensation build-up on the inside of the headlight lens does not indicate a
malfunction. Contact your Lexus dealer for mo re information in the following situations:
●Large drops of water have built up on the inside of the lens.
●Water has built up inside the headlight.
■When replacing light bulbs
→P. 388
WARNING
■Replacing light bulbs
●Turn off the lights. Do not attempt to replac e the bulb immediately after turning off the
lights.
The bulbs become very hot and may cause burns.
●Do not touch the glass portion of the light bu lb with bare hands. When it is unavoid-
able to hold the glass portion, use and hold with a clean dry cloth to avoid getting
moisture and oils on the bulb.
Also, if the bulb is sc ratched or dropped, it may blow out or crack.
●Fully install light bulbs and any parts used to secure them. Failure to do so may result
in heat damage, fire, or water entering th e headlight unit. This may damage the head-
lights or cause condensation to build up on the lens.
■To prevent damage or fire
●Make sure bulbs are fully seated and locked.
●Check the wattage of the bulb before installing to prevent heat damage.

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7When trouble arises
7-1. Essential information Emergency flashers .................. 396
If your vehicle has to be stopped in an emergency.... 397
7-2. Steps to take in an emergency If your vehicle needs to be towed................................398
If you think something is wrong ................403
If a warning light turns on or a warning buzzer sounds.....404
If a warning message is displayed ................................. 410
If you have a flat tire ....................441
If the hybrid system will not start................................450
If the parking brake cannot be released ................................ 452
If the electronic key does not operate properly ..................... 454
If the 12-volt battery is discharged ............................. 457
If your vehicle overheats .......... 461
If the vehicle becomes stuck ............................................. 466

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7-2. Steps to take in an emergency
If a warning light turns on or a warning buzzer
sounds
Calmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, but then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspecte d by your Lexus dealer.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
(U.S.A.)
(Canada)
Brake system warning light (warning buzzer) •Low brake fluid
• Malfunction in the electronically controlled brake system
→ Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
(If equipped)
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
→ Immediately stop the vehicle in a safe place and contact your
Lexus dealer.
(U.S.A.)
(Canada)
Malfunction indicator lamp Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system;
• The electronic throttle control system; or
• The electronic hybrid transmission control system
→ Have the vehicle inspected by your Lexus dealer immediately.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
→ Have the vehicle inspected by your Lexus dealer immediately.
(U.S.A.)
(Canada)
ABS warning light Indicates a malfunction in:
• The ABS; or
• The brake assist system
→ Have the vehicle inspected by your Lexus dealer immediately.

4057-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
7
When trouble arises
Electric power steering system warning light (warning buzzer)
Indicates a malfunction in the EPS (Electric Power Steering) sys-
tem
→ Have the vehicle inspected by your Lexus dealer immediately.
(Flashes or illuminates)
(If equipped)
PCS warning lightIndicates a malfunction in the PCS (Pre-Collision System) or that
the system is temporarily unavailable due to the vehicle being
extremely hot/cold, or dirt ar ound a front sensor, etc. (→P. 233,
410)
→ Follow the instructions displayed on the multi-information dis-
play. ( →P. 233, 410)
If the PCS (Pre-Collision System ) or VSC (Vehicle Stability Con-
trol) system is disabled, the PC S warning light will illuminate.
→ P. 233
Slip indicator
Indicates a malfunction in:
• The VSC system;
• The TRAC system; or
• The hill-start assist control system;
→ Have the vehicle inspected by your Lexus dealer immediately.
The light will flash when the VSC, TRAC or ABS system is operat-
ing.
(Flashes)
(If equipped)
“AFS OFF” indicator
Indicates a malfunction in the adaptive front-lighting system
→ Have the vehicle inspected by your Lexus dealer immediately.
(Flashes)
Brake hold operated indicator
Indicates a malfunction in the brake hold system
→ Have the vehicle inspected by your Lexus dealer immediately.
Warning lightWarning light/Details/Actions

4067-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
(Flashes)(U.S.A.)
(Flashes)
(Canada)Parking brake indicator
Indicates a malfunction in the parking brake system
→ Have the vehicle inspected by your Lexus dealer immediately.
Brake system warning light
Indicates a malfunction in:
• The electronically controlled brake system;
• The regenerative braking system; or
• The parking brake system
→ Have the vehicle inspected by your Lexus dealer immediately.
Low fuel level warning light
Except F SPORT models: Indicates remaining fuel is approximately
2.6 gal. (10.0 L, 2.2 Imp.gal.) or less
F SPORT models: Indicates remaining fuel is approximately
2.6 gal. (9.9 L, 2.2 Imp.gal.) or less
→ Refuel the vehicle.
Seat belt reminder light (warning buzzer)*
Warns the driver and/or front passenger to fasten their seat belts
→ Fasten the seat belt.
If the front passenger’s seat is occupied, the front passenger’s
seat belt also needs to be fastened to make the warning light
(warning buzzer) off.
Master warning light
A buzzer sounds and the warning light comes on and flashes to
indicate that the master warnin g system has detected a malfunc-
tion.
→ P. 410
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as
• Natural causes ( →P. 408)
•Flat tire ( →P. 441)
→ Adjust the tire inflation pres sure to the specified level.
The light will turn off after a few minutes. In case the light does
not turn off even if the tire inflation pressure is adjusted, have the
system checked by your Lexus dealer.
When the light comes on af ter blinking for 1 minute:
Malfunction in the tire pressure warning system
→ Have the system checked by your Lexus dealer.
Warning lightWarning light/Details/Actions