2021 LEXUS IS300 check engine

3006-3. Do-it-yourself maintenance
Check the radiator, condenser and
intercooler radiator (if equipped) and
clear away any foreign objects.
If any of the above parts are extremely
dirty or you are not sure of their condi-
tion, have your vehicle inspected by
your Lexus dealer.
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■Adding fluid
Make sure to check the fluid type and
prepare the necessary item.
 Fluid type
SAE J1703 or FMVSS No.116 DOT 3
brake fluid
Item
Clean funnel
■Brake fluid can absorb moisture from
the air
Excess moisture in the brake fluid can cause
a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
WARNING
■When the engine is hot
Do not remove the engine coolant reser-
voir cap, intercooler coolant reservoir
cap (IS300), or coolant inlet cap.
(  P.367)
The cooling system may be under pres-
sure and may spray hot coolant if the cap
is removed, causing serious injuries, such
as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor
straight antifreeze. The correct mixture
of water and antifreeze must be used to
provide proper lubrication, corrosion
protection and cooling. Be sure to read
the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to pre-
vent it from damagi ng parts or paint.
Checking the radiator, con-
denser and intercooler radiator
(if equipped)
WARNING
■When the engine is hot
Do not touch the radiator, condenser or
intercooler radiator (if equipped) as they
may be hot and cause serious injuries,
such as burns.
Checking and adding the brake
fluid
WARNING
■When filling the reservoir
Take care as brake fluid can harm your
hands and eyes and damage painted sur-
faces.
If fluid gets on your hands or in your eyes,
flush the affected area with clean water
immediately.
If you still experience discomfort, see a
doctor.

3016-3. Do-it-yourself maintenance
6
Maintenance and care
Check the battery as follows.
■Battery exterior
Make sure that the battery terminals
are not corroded and that there are no
loose connections, cracks, or loose
clamps.
Terminals
Hold-down clamp
■Before recharging
When recharging, the battery produces
hydrogen gas which is flammable and
explosive. Therefore, observe the following
before recharging:
●If recharging with the battery installed on
the vehicle, be sure to disconnect the
ground cable.
●Make sure the power switch on the char-
ger is off when connecting and discon-
necting the charger cables to the battery.
■After recharging/reconnecting the bat-
tery
The engine may not start. Follow the proce-
dure below to initialize the system.
1 Shift the shift lever to P.
2 Open and close any of the doors.
3 Restart the engine.
●Unlocking the doors using the smart
access system with pu sh-button start may
not be possible immediately after recon-
necting the battery. If this happens, use
the wireless remote control or the
mechanical key to lo ck/unlock the doors.
●Start the engine with the engine switch in
ACCESSORY mode. The engine may
not start with the engine switch turned off.
However, the engine will operate nor-
mally from the second attempt.
●The engine switch mode is recorded by
the vehicle. If the battery is disconnected
and reconnected, the vehicle will return
the engine switch mode to the status it
was in before the battery was discon-
nected. Make sure to turn off the engine
before disconnecting the battery. Take
extra care when connecting the battery if
the engine switch mode prior to the bat-
tery being disconnected is unknown.
If the system will not start even after multiple
attempts, contact your Lexus dealer.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go
down slightly as the brake pads wear out
or when the fluid level in the accumulator
is high.
If the reservoir need s frequent refilling,
there may be a serious problem.
Battery
A
B
WARNING
■Chemicals in the battery
Batteries contain poisonous and corro-
sive sulfuric acid and may produce
hydrogen gas which is flammable and
explosive. To reduce the risk of death or
serious injury, take the following precau-
tions while working on or near the bat-
tery:
●Do not cause sparks by touching the
battery terminals with tools.
●Do not smoke or light a match near the
battery.
●Avoid contact with eyes, skin and
clothes.

3056-3. Do-it-yourself maintenance
6
Maintenance and care
Rotate the tires in the order shown.
Vehicles with front and rear tires of
the same size
To equalize tire wear and extend tire
life, Lexus recommends that tire rota-
tion is carried out at the same interval
as tire inspection.
Do not fail to initialize the tire pressure
warning system after tire rotation.
Vehicles with front and rear tires of
differing sizes
Tires cannot be rotated.
■When rotating the tires
Make sure that the engine switch is off. If the
tires are rotated while the engine switch is in IGNITION ON mode, the tire position
information will not be updated.
If this accidentally occurs, either turn the
engine switch to off and then to IGNITION
ON mode, or initialize the system after
checking that the tire pressure is properly
adjusted.
Your vehicle is equipped with a tire
pressure warning system that uses tire
pressure warning valves and transmit-
ters to detect low ti
re inflation pressure
before serious problems arise.
 The tire pressure detected by the
tire pressure warning system can be
displayed on the multi-information
display.
 If the tire pressure drops below a
predetermined level, the driver is
warned by a screen display and a
warning light. ( P.341)
NOTICE
●Be sure to use proper tire inflation
pressure. If tires are under-inflated,
they may be damaged more severely.
●Avoid potholes, uneven pavement,
curbs and other road hazards. Failure
to do so may lead to severe tire and
wheel damage.
■If tire inflation pres sure of each tire
becomes low while driving
Do not continue driving, or your tires
and/or wheels may be ruined.
Tire rotation
Tire pressure warning system

3066-3. Do-it-yourself maintenance
■Routine tire inflation pressure checks
The tire pressure warning system does not
replace routine tire inflation pressure
checks. Make sure to check tire inflation
pressure as part of your routine of daily
vehicle checks.
■Tire inflation pressure
●It may take a few minutes to display the
tire inflation pressure after the engine
switch is turned to IGNITION ON mode.
It may also take a few minutes to display
the tire inflation pres sure after inflation
pressure has been adjusted.
●Tire inflation pressure changes with tem-
perature. The displayed values may also
be different from the values measured
using a tire pressure gauge.
■Situations in which the tire pressure
warning system may not operate prop-
erly
●In the following cases, the tire pressure
warning system may not operate prop-
erly.
• If non-genuine Lexus wheels are used.
• If a tire has been repl aced with a tire that
is not an OE (Original Equipment) tire.
• If a tire has been repl aced with a tire that
is not of the specified size.
• If tire chains, etc. are installed.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects the 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 extremely
higher than the specified level.
• If tires not equipped with tire pressure warning valves and tr ansmitters are used.
• If the ID code on the tire pressure warn- ing valves and transmitters is not regis-
tered in the tire pressure warning
computer.
●Performance may be affected in the fol-
lowing situations.
• When driving near a TV tower, electric
power plant, gas station, radio station,
large display, airport or other facility that
generates strong radio waves or electri- cal 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 pr essure declines rap-
idly for example when a tire has burst, the
warning may not function.
■Warning performance of the tire pres-
sure warning system
The warning of the tire pressure warning
system will change in accordance with driv-
ing conditions. For this reason, the system
may give a warning even if the tire pressure
does not reach a low enough level, or if the
pressure is higher than the pressure that
was adjusted to when the system was initial-
ized.

3156-3. Do-it-yourself maintenance
6
Maintenance and care
1Turn the engine switch off.
2 Open the glove box. Lift up the side
with the stay, disconnect the stay
tabs and remove the partition by
pulling horizontally.
3 Press the tabs and remove the filter
cover. 4
Press the tabs and remove the filter
case.
5 Remove the air conditioning filter
from the filter case and replace it
with a new one.
The “ UP” marks shown on the filter
and the filter case sh ould be pointing up.
■Checking interval
Inspect and replace the air conditioning fil-
ter according to the maintenance schedule.
In dusty areas or areas with heavy traffic
flow, early replacement may be required.
(For scheduled maintenance information,
please refer to the “Owner’s Manual Sup-
plement” or “Scheduled Maintenance”.)
■If air flow from the vents decreases dra-
matically
The filter may be clogged. Check the filter
and replace if necessary.
■Air conditioning filt er with deodorizing
function
When fragrances are placed in your vehi-
cle, the deodorizing effect may become
significantly weakened in a short period.
Air conditioning filter
The air conditioning filter must be
changed regularly to maintain air
conditioning efficiency.
Removal method

3186-3. Do-it-yourself maintenance
1Turn the engine switch off.
2 Open the fuse box cover.
Engine compartment: type A fuse
box
Push the tab in and lift the lid off.
Engine compartment: type B fuse
box
Push the tab in and lift the lid off.
Driver’s side instrument panel
Remove the lid.
3Remove the fuse with the pullout
tool.
Only type A fuses can be removed
using the pullout tool.
4 Check if the fuse is blown.
Type A and B:
Replace the blown fuse with a new fuse of
an appropriate amperage rating. The
amperage rating can be found on the fuse
box lid.
Type C and D:
Contact your Lexus dealer.
Type A
Normal fuse
Checking and replacing
fuses
If any of the electrical components
do not operate, a fuse may have
blown. If this happens, check and
replace the fuses as necessary.
Checking and replacing fuses
A

3447-2. Steps to take in an emergency
●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 steeri ng system warning
light may come on and the warning buzzer
may sound.
■When the tire pressure warning light
comes on
Inspect the tires to check if a tire is punc-
tured.
If a tire is punctured: P.349
If none of the tires are punctured:
Turn the engine switch off then turn it to
IGNITION ON mode. Check if the tire
pressure warning light comes on or blinks.
If the tire pressure wa rning light blinks for
approximately 1 minute then stays on
There may be a malfunction in the tire
pressure warning syst em. Have the vehicle
inspected by your Lexus dealer immedi-
ately.
If the tire pressure warning light comes
on
1 After the temperature of the tires has
lowered sufficiently, check the inflation
pressure of each tire and adjust them to
the specified level.
2 If the warning light does not turn off
even after several minutes have
elapsed, check that the inflation pres-
sure of each tire is at the specified level
and perform initialization. ( P.308)
■The tire pressure warning light may
come on due to natural causes
The tire pressure wa rning light may come
on due to natural causes such as natural air
leaks and tire inflation pressure changes
caused by temperature. In this case, adjust-ing the tire inflation pressure will turn off the
warning light (after a few minutes).
■When a tire is replaced with the spare
tire
The spare tire is not equipped with a tire
pressure 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 warn-
ing system may not function properly
 P.306
WARNING
■If both the ABS and the brake system
warning lights remain on
Stop your vehicle in a safe place immedi-
ately and contact your Lexus dealer.
The vehicle will become extremely
unstable during br aking, and the ABS
system may fail, which could cause an
accident resulting in death or serious
injury.
■When the electric power steering
system warning light comes on
When the light comes on yellow, the
assist to the power st eering is restricted.
When the light comes on red, the assist
to the power steering is lost and handling
operations of the steering wheel become
extremely heavy.
When steering wheel operations are
heavier than usual, grip the steering
wheel firmly and operate it using more
force than usual.
■If the tire pressure warning light
comes on
Be sure to observe the following precau-
tions.
Failure to do so could cause a loss of
vehicle control and result in death or
serious injury.
●Decelerate to the lowest appropriate
speed as soon as possible. Do not
drive over 50 mph (80 km/h).

3467-2. Steps to take in an emergency
■Warning messages
The warning messages explained below
may differ from the actual messages
according to operation conditions and vehi-
cle specifications.
■Warning buzzer
A buzzer may sound when a message is dis-
played.
The buzzer may not be audible if the vehicle
is in a noisy location or if the audio system
volume is high.
■If “Engine Oil Level Low Add or
Replace” is displayed
The engine oil level is low. Check the level
of the engine oil, and add if necessary.
This message ma y appear if the vehicle is
stopped on a slope. Move the vehicle to a
level surface and chec k to see if the mes-
sage disappears.
WARNING
TPMS (tire pressure warning system)
malfunctions may occur for a variety of
reasons, including th e installation of
replacement or alternate tires or wheels
on the vehicle that prevent the TPMS
(tire pressure warning system) from func-
tioning properly. Always check the
TPMS (tire pressure warning system)
malfunction telltale after replacing one
or more tires or wheels on your vehicle to
ensure that the replacement or alternate
tires and wheels allow the TPMS (tire
pressure warning system) to continue to
function properly.
NOTICE
■To ensure the tire pressure warning
system operates properly
Do not install tires wi th different specifi-
cations or makers, as the tire pressure
warning system may not operate prop-
erly.
If a warning message is dis-
played
The multi-information display
shows warnings for system malfunc-
tions and incorrectly performed
operations, and messages that indi-
cate a need for maintenance.
When a message is displayed, per-
form the appropriate corrective
action for the message.
If a warning message is displayed
again after the appropriate actions
have been performed, contact your
Lexus dealer.
Additionally, if a warning light
comes on or flashes at the same
time that a warning message is dis-
played, take the appropriate cor-
rective action for the warning light.
(  P.337)