2020 LEXUS RC300 wiring

2386-1. Maintenance and care
Remove dirt and dust using a vac-
WARNING
■Water in the vehicle
●Do not splash or spill liquid in the vehi-
cle.
Doing so may cause electrical compo-
nents, etc. to malfunction or catch fire.
●Do not get any of the SRS components
or wiring in the vehicle interior wet.
(  P.28)
An electrical malfunction may cause the
airbags to deploy or not function prop-
erly, resulting in death or serious injury.
■Cleaning the interior (especially
instrument panel)
Do not use polish wax or polish cleaner.
The instrument panel may reflect off the
windshield, obstructing the driver’s view
and leading to an accident, resulting in
death or serious injury.
NOTICE
■Cleaning detergents
●Do not use the following liquids, as
they may discolor the vehicle interior
or cause streaks or damage to painted
surfaces:
• Center Display: Organic substances such as benzine or gasoline, alkaline
solutions, and alcohol
• Seats: Alkaline solutions, organic sub- stances such as thinner or benzine,
and alcohol
• Other parts: Organic substances such as benzine or gasoline, alkaline or
acidic solutions, dye, and bleach
●Do not use polish wax or polish
cleaner. The instrument panel’s or
other interior part’s painted surface
may be damaged.
■Preventing damage to leather sur-
faces
Observe the following precautions to
avoid damage to and deterioration of
leather surfaces:
●Remove any dust or dirt from leather
surfaces immediately.
●Do not expose the vehicle to direct
sunlight for extended periods of time.
Park the vehicle in the shade, espe-
cially during summer.
●Do not place items made of vinyl, plas-
tic, or containing wax on the uphol-
stery, as they may stick to the leather
surface if the vehicle interior heats up
significantly.
■Water on the floor
Do not wash the vehicle floor with water.
Vehicle systems such as the audio system
may be damaged if water comes into
contact with electrical components such
as the audio system above or under the
floor of the vehicle. Water may also
cause the body to rust.
■When cleaning the inside of the wind-
shield
Do not allow glass cleaner to contact the
lens. Also, do not touch the lens.
(  P.152)
■Cleaning the inside of the rear win-
dow
●Do not use glass cleaner to clean the
rear window, as this may cause dam-
age to the rear window defogger
heater wires or antenna. Use a cloth
dampened with lukewarm water to
gently wipe the window clean. Wipe
the window in strokes running parallel
to the heater wires or antenna.
●Be careful not to scratch or damage
the heater wires or antenna.
Cleaning the leather areas

2706-3. Do-it-yourself maintenance
Type BNormal fuse
Blown fuse
Type C
Normal fuse
Blown fuse
Type DNormal fuse
Blown fuse
■After a fuse is replaced
●If the lights do not turn on even after the fuse has been replaced, a bulb may need
replacement.
●If the replaced fuse blows again, have the
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 cir-
cuits designed to prevent overload,
non-genuine parts or parts not designed for
this vehicle may be unusable.
A
B
A
B
A
B
WARNING
■To prevent system breakdowns and
vehicle fire
Observe the following precautions.
Failure to do so may cause damage to
the 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.

2897-2. Steps to take in an emergency
7
When trouble arises
reaches a certain speed.
■Master warning light (warning buzzer)
■Tire pressure warning light
■SRS warning light
This warning light system monitors the air-
bag sensor assembly, fr ont impact sensors,
side impact sensors (door), side impact
sensors (front), side impact sensors (rear),
driver’s seat position sensor, driver’s seat
belt buckle switch, front passenger occu-
pant classification system, “AIR BAG ON”
indicator light, “AIR BAG OFF” indicator
light, front passenger’s seat belt buckle
switch, seat belt pret ensioners, airbags,
interconnecting wiring and power sources.
(  P.29)
■Front passenger detection sensor, seat
belt reminder and warning buzzer
●If luggage is placed on the front passen-
ger seat, the front passenger detection
sensor may cause th e warning light to
flash and the warning buzzer to sound
even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sen- sor may not detect a passenger, and the
warning light may not operate properly.
■If the malfunction indicator lamp comes
on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel 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 several
trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning
light (warning buzzer)
When the battery charge becomes insuffi-
cient or the voltage temporarily drops, the
electric power steering system warning
light may come on and the warning buzzer
may sound.
Warning lightDetails/Actions
A buzzer sounds and the warning light comes on and flashes to indicate
that the master warning system has detected a malfunction.
 P.292
Warning lightDetails/Actions
When the light comes on:
Low tire inflation pressure such as
Natural causes ( P.290)
 Flat tire ( P.296)
 Adjust the tire inflation pressure 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 adju sted, have the system checked by
your Lexus dealer.
When the light comes on after blinking for 1 minute:
Malfunction in the tire pressure warning system
 Have the system checked by your Lexus dealer.