2021 LEXUS IS300 wiring

2846-1. Maintenance and care
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
properly, 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:
• Audio system screen: Organic sub- stances 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.164)
■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.

3196-3. Do-it-yourself maintenance
6
Maintenance and care
Blown fuse
Type BNormal fuse
Blown fuse
Type CNormal 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.
B
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.

3437-2. Steps to take in an emergency
7
When trouble arises
■Slip indicator
■Parking brake indicator (warning buzzer)
■Brake hold operated indicator (warning buzzer)
■Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound.
■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.
■SRS warning light
This warning light system monitors the air-
bag sensor assembly, fr ont impact sensors,
side impact sensors (front door), side
impact sensors (front), side impact sensors
(rear), driver’s seat position sensor, driver’s
seat belt buckle sw itch, front passenger
occupant classificatio n system (ECU and
sensors), “AIR BAG ON” indicator light,
“AIR BAG OFF” indicator light, front pas-
senger’s seat belt buckle switch, seat belt
pretensioners and force limiters, airbags,
interconnecting wiring and power sources.
(  P.28)
■If the malfunction indicator lamp comes
on while driving
First check the following:
Warning lightDetails/Actions
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.
Warning lightDetails/Actions
(flashes)
(U.S.A.)
or
(flashes)
(Canada)
It is possible that the parking brake is not fully engaged or released
 Operate the parking brake switch once again.
This light comes on when the parking brake is not released. If the light
turns off after the parking brake is fu lly released, the system is operating
normally.
Warning lightDetails/Actions
(flashes)
Indicates a malfunction in the brake hold system
 Have the vehicle inspected by your Lexus dealer immediately.