2018 LEXUS RC350 warning light

4186-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
WARNING
■When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drivetrain 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 a compact spare tire: Do no t tow if your vehicle has a compact spare
tire installed.
●Vehicles with an emergency tire puncture repair kit: Do not tow anything if a tire that
has been repaired using the emergency tire puncture 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 operate the tire pressure warning reset switch without first adjusting the tire
inflation pressure to the spec ified level. Otherwise, the tire pressure warning light may
not come on even if the tire inflation pressu re is low, or it may 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.

4316-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
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. 432)
●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.

4406-3. Do-it-yourself maintenance
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
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.

441
When trouble arises7
RC350_RC300 AWD_RC300_RC F_U(OM24748U)
7-1. Essential information
Emergency flashers .................. 442
If your vehicle has to be stopped in
an emergency .......................... 443
7-2. Steps to take in an emergency
If your vehicle needs to be towed ........................................... 444
If you think something is wrong ............................................ 451
Fuel pump shut off system ...... 452
If a warning light turns on or a warning buzzer
sounds.......................................... 453
If a warning message is displayed.....................................460
If you have a flat tire (vehicles with a
spare tire) ...................................489
If you have a flat tire (vehicles with
an emergency
tire puncture repair kit) ........502
If the engine will not start ......... 516
If the electronic key does not operate properly .............. 518
If the vehicle battery is discharged ................................. 522
If your vehicle overheats ......... 526
If the vehicle becomes stuck ............................................. 532

4537-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
7
When trouble arises
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 Indicates that:
• The brake fluid level is low; or
• The brake system is malfunctioning
 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.

4547-2. Steps to take in an emergency
RC350_RC300 AWD_RC300_RC F_U(OM24748U)
(U.S.A.)
(Canada)Parking brake warning light (warning buzzer)*1
Indicates that the parking brake is engaged
 Release the parking brake.
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.
LDA (Lane Departure Alert) indicator
If the LDA indicato r is illuminated:
Indicates a malfunction in the LDA (Lane Departure Alert with
steering control) system.
 Check the warning message displa yed on the multi-information
display. ( P. 460)
If the LDA indicator flashes:
Indicates that the vehicle has deviated from the lane (while the
LDA [Lane Departure Alert with stee ring control] system is oper-
ating)
 Check the area around the vehicle and return the vehicle to
between the lane lines.
(Flashes or illuminates)
PCS warning light
Indicates 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.
 Follow the instructions displayed on the multi-information dis-
play. ( P. 260, 470)
If the PCS (Pre-Collision System ) or VSC (Vehicle Stability Con-
trol) system is disabled, the PC S warning light will illuminate.
(  P. 260)
Slip indicator
Indicates a malfunction in:
• The VSC (Vehicle Stability Control) system;
• The TRAC (Traction Control) system; or
• The hill-start assist control system
The light will flash when the VSC or the TRAC system is operating.
 Have the vehicle inspected by your Lexus dealer immediately.
(If equipped)
Automatic headlight leveling system warning light
Indicates a malfunction in the automatic headlight leveling system
 Have the vehicle inspected by your Lexus dealer immediately.
Open door warning light (warning buzzer)*2
Indicates that a door or the trunk is not fully closed
 Check that both side doors and the trunk are closed.
Warning lightWarning light/Details/Actions

4557-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
7
When trouble arises
Low fuel level warning light
Indicates that remaining fuel is approximately 2.6 gal. (10 L, 2.2
Imp. gal.) or less
 Refuel the vehicle.
Seat belt reminder light (warning buzzer)*3
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) turn off.
Rear passengers’ seat belt re minder lights (warning buzzer)*3
Warns the rear passengers to fasten their seat belts
 Fasten the seat belt.
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. 460
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as
• Natural causes ( P. 457)
•Flat tire ( P. 489, 502)
 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

4577-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)
7
When trouble arises
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors, side
impact sensors (door), side impact sensors (front), side im pact sensors (rear), driver’s
seat position sensor, driver’s seat belt buckle switch, front passenger occupant classifica-
tion system, “AIR BAG ON” indicator light, “A IR BAG OFF” indicator light, front passen-
ger’s seat belt buckle switch, seat belt pretensioners, airbags, interconnecting wiring and
power sources. ( P. 41)
■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 pressu re and adjust to the appropriate level. Pushing the tire
pressure warning reset switch will not tu rn 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 the spare tire (if equipped)
The spare tire is not equipped with a tire pr essure warning valve and transmitter. 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. 417
■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.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.