warning light Lexus GS350 2019 Repair Manual

GS350_300_OM_OM30G96U_(U)
4036-3. 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.
●Vehicles with spare tire: Do not tow if your vehicle has a spare tire installed.
●Vehicles with emergency tire puncture repair kit: Do not tow anything if a tire that has
been repaired using the emergency tire punc ture repair kit is installed. The load on
the tire may cause unexpected damage to the tire.
■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.

GS350_300_OM_OM30G96U_(U)
4176-3. Do-it-yourself maintenance
6
Maintenance and care
■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. 420)
●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.

GS350_300_OM_OM30G96U_(U)
4236-3. Do-it-yourself maintenance
6
Maintenance and care
■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. 417
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.

425
GS350_300_OM_OM30G96U_(U)
7When trouble arises
7-1. Essential informationEmergency flashers...................426
If your vehicle has to be stopped in an
emergency ................................. 427
If the vehicle is trapped in rising water ................................428 7-2. Steps to take in an
emergency
If your vehicle needs to be towed................................ 429
If you think something is wrong ................ 435
Fuel pump shut off system ...... 436
If a warning light turns on or a warning buzzer
sounds.......................................... 437
If a warning message is displayed..................................... 444
If you have a flat tire (vehicles with spare tire) ......................... 475
If you have a flat tire (vehicles without spare tire)...................486
If the engine will not start ....... 500
If the parking brake cannot be released ................................502
If the electronic key does not operate properly .....................504
If the vehicle battery is discharged ................................. 507
If your vehicle overheats .......... 512
If the vehicle becomes stuck .............................................. 518

437
GS350_300_OM_OM30G96U_(U)
7
When trouble arises
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 brake booster 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 electronic engine control system;
• The electronic throttle control system; or
• The electronic automatic 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.

4387-2. Steps to take in an emergency
GS350_300_OM_OM30G96U_(U)
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 around a front sensor, etc.
( P. 255, 444)
 Follow the instructions displayed on the multi-information dis-
play. ( P. 255, 444)
If the PCS (Pre-Collision System ) or VSC (Vehicle Stability Con-
trol) system is disabled, the PC S warning light will illuminate.
 P. 299
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 or TRAC system is operating.
(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.
Warning lightWarning light/Details/Actions

4397-2. Steps to take in an emergency
GS350_300_OM_OM30G96U_(U)
7
When trouble arises
(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 parking brake system
 Have the vehicle inspected by your Lexus dealer immediately.
(GS F only)
Open door warning light (warning buzzer)*1
Indicates that a door or the trunk is not fully closed
 Check that all the doors and the trunk are closed.
Low fuel level warning light
Except F SPORT models of GS350/GS300, and GS F: Indicates
remaining fuel is approximately 2. 6 gal. (10.0 L, 2.2 Imp.gal.) or
less
F SPORT models of GS350/GS300: 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)*2
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. 444
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as
• Natural causes ( P. 441)
•Flat tire ( P. 475, 486)
 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

4407-2. Steps to take in an emergency
GS350_300_OM_OM30G96U_(U)
*1: Open door warning buzzer: P. 444
*2: 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 engine switch is turned to IGNITION ON mode, the buzzer
sounds for 6 seconds. If the vehicle reaches a speed of 12 mph (20 km/h), the buzzer
sounds once. If the seat belt is still unfast ened 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 different 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.
(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. 454, 455
Warning lightWarning light/Details/Actions

4417-2. Steps to take in an emergency
GS350_300_OM_OM30G96U_(U)
7
When trouble arises
■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. 43)
■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 battery charge becomes insufficien t or the voltage temporarily drops, the
electric power steering system warning li ght may come on and the warning buzzer may
sound.
■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. 400
■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
engine switch is turned to IGNITION ON mo de, have it checked by your Lexus dealer.

4427-2. Steps to take in an emergency
GS350_300_OM_OM30G96U_(U)
■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. 549)
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.