ignition LEXUS IS300 2021 Service Manual

2926-3. Do-it-yourself maintenance
Light bulbs
( P.321)
•Bulb with same num-
ber and wattage rat-
ing as original
• Phillips-head screw- driver
•Flathead screw- driver
•Wrench
Radiator, con-
denser and inter-
cooler radiator
(  P.300)

Tire inflation pres-
sure ( P.312)• Tire pressure gauge
•Compressed air
source
Washer fluid
( P.302)
• Water or washer
fluid containing anti-
freeze (for winter
use)
• Funnel (used only for adding water or
washer fluid)
WARNING
The engine compartment contains many
mechanisms and fluids that may move
suddenly, become hot, or become elec-
trically energized. To avoid death or seri-
ous injury, observe the following
precautions.
■When working on the engine com-
partment
●Keep hands, clothi ng and tools away
from the moving fan and engine drive
belt.
●Be careful not to touch the engine,
radiator, exhaust manifold, etc. right
after driving as they may be hot. Oil
and other fluids may also be hot.
ItemsParts and tools●Do not leave anything that may burn
easily, such as paper and rags, in the
engine compartment.
●Do not smoke, cause sparks or expose
an open flame to fuel or the battery.
Fuel and battery fumes are flammable.
●Be extremely cautious when working
on the battery. It contains poisonous
and corrosive sulfuric acid.
■When working near the electric cool-
ing fans or radiator grille
Be sure the engine switch is off.
With the engine switch in IGNITION
ON mode, the electric cooling fans may
automatically start to run if the air condi-
tioning is on and/or the coolant tempera-
ture is high. ( P.300)
■Safety glasses
Wear safety glasses to prevent flying or
falling material, fluid spray, etc. from get-
ting in your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter
removed may cause excessive engine
wear due to dirt in the air.

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.

3096-3. Do-it-yourself maintenance
6
Maintenance and care
multi-information display.
5Drive straight (with occasional left
and right turns) at approximately
25 mph (40 km/h) or more for
approximately 10 to 30 minutes.
Initialization is complete when the position
of each tire is determined and the inflation
pressure of each tire is displayed on the
multi-information display.
■Initialization procedure
●Make sure to perform the initialization
procedure after adjusting the tire inflation
pressure.
Also, make sure the tires are cold before
performing the initialization procedure or
adjusting the tire inflation pressure.
●If you have accidentally turned the engine
switch off during initialization, it is not
necessary to press the reset switch again
as initialization will restart automatically
when the engine switch has been turned
to IGNITION ON mode for the next
time.
●If you accidentally pr ess the reset switch
when initialization is not necessary, adjust
the tire inflation pres sure to the specified
level when the tires are cold, and conduct
initialization again.
●While the position of each tire is being
determined and the inflation pressures
are not being displayed on the
multi-information display, if the inflation
pressure of a tire drops, the tire pressure
warning light will come on.
■If the tire pressure warning system is not
initialized properly
●In the following situations, initialization
may take longer than usual to be com-
pleted or may not be possible. (Usually,
the vehicle will need to be driven for
approximately 10 to 30 minutes to com-
plete initialization.) If initialization is not
complete after drivin g approximately 30
minutes, continue driving for a while.
• If the vehicle is driven on an unpaved
road, it may take longer to complete ini-
tialization.
• If the vehicle is backed up while perform-
ing initialization, data collected during ini-
tialization will be cleared and it will take
longer than normal to complete.
• If the vehicle is driven in heavy traffic or another situation where other vehicles
are driven close by, it may take time for
the system to recognize the tire pressure
warning valve and transmitters of your
vehicle over those of other vehicles.
If initialization is not complete after driving
for approximately 1 hour, park the vehicle in
a safe place for approximately 20 minutes
and then drive the vehicle again.
●In the following situations, initialization
will not be started or was not completed
properly and the system will not operate
properly. Perform the initialization proce-
dure again.
• If, when attempting to start initialization,
the tire pressure warning light does not
blink 3 times.
• If, when the vehicle has been driven for
about 20 minutes after performing ini-
tialization, the tire pressure warning light
blinks for approximately 1 minute and
then illuminates.
●If initialization canno t be completed after
performing the above procedure, con-
tact your Lexus dealer.

3116-3. Do-it-yourself maintenance
6
Maintenance and care
before driving the vehicle.
If the vehicle is driven after ID code regis-
tration is started, to cancel registration,
perform the ID code registration start
procedure again and turn the engine
switch off before driving.
●If ID code registration has been canceled,
the tire pressure warning light will blink
for approximately 1 minute when the
engine switch is turned to IGNITION
ON mode and then illuminate. The tire
pressure warning system will be opera-
tional when the tire pressure warning
light turns off.
●If the warning light does not turn off even
after several minutes have elapsed, ID
code registration may not have been can-
celled correctly. To ca ncel registration,
perform the ID code registration start
procedure again and th en turn the engine
switch off before driving.
■If ID codes are not registered properly
●In the following situations, ID code regis-
tration may take longer than usual to be
completed or may not be possible. (Usu-
ally, the vehicle will need to be driven for
approximately 10 to 30 minutes to com-
plete ID code registration.)
If ID code registration is not complete
after driving for approximately 30 min-
utes, continue driving for a while.
• If the vehicle is driven on an unpaved road, it may take longer than normal to
complete registration.
• If the vehicle is backed up while perform- ing registration, data collected during
registration will be cleared, and it will take
longer than normal to complete.
• If the vehicle is driven in heavy traffic or another situation where other vehicles
are driven close by, it may take time for
the system to recognize the tire pressure
warning valve and tran smitters of your
vehicle over those of other vehicles.
• If a wheel with a tire pressure warning valve and transmitter installed is inside or
near the vehicle, registration of the ID
codes for the installed wheels may not be
possible.
If ID registration is not complete after driv-
ing for approximately 1 hour, park the vehi-
cle in a safe place for approximately 20 minutes and then perform the ID code reg-
istration procedure again.
●In the following situations, ID code regis-
tration will not be started or was not com-
pleted properly and the system will not
operate properly. Pe
rform the ID code
registration procedure again.
• If, when attempting to start ID code regis-
tration, the tire pressure warning light
does not blink slowly 3 times.
• If, when the vehicle has been driven for
about 20 minutes after performing ID
code registration, the tire pressure warn-
ing light blinks for approximately 1 minute
and then illuminates.
●If ID code registration cannot be com-
pleted after performing the above proce-
dure, contact your Lexus dealer.

3347-2. Steps to take in an emergency
3Insert the towing eyelet into the
hole and tighten partially by hand.
4 Tighten down the towing eyelet
securely using a wheel bolt wrench
or hard metal bar.
5 Securely attach cables or chains to
the towing eyelet.
Take care not to damage the vehicle body.
6Enter the vehicle being towed and
start the engine.
If the engine does not start, turn the engine
switch to IGNITION ON mode.
7Shift the shift lever to N and release
the parking brake.
Turn automatic mode off. ( P.144)
When the shift lever cannot be shifted:
 P.139
■While towing
If the engine is not running, the power assist
for the brakes and steering will not function,
making steering and braking more difficult.
■Wheel bolt wrench
Wheel bolt wrench is in stalled in the trunk.
(  P.349)

3407-2. Steps to take in an emergency
■Electric power steering system warning light (warning buzzer)
■Low fuel level warning light
■Driver’s and front passenger’s seat belt reminder light (warning buzzer)*
*: Driver’s seat belt warning buzzer:
The driver’s seat belt warning buzzer sounds to al ert the driver that his or her seat belt is not
fastened. Once the engine switch is turned to IGNITION ON mode, the buzzer sounds. If
the seat belt is still unfastened, the buzzer sounds intermittently for a certain period of time
after the vehicle reaches a certain speed.
Front passenger’s seat belt warning buzzer:
The front passenger’s seat belt warning buzzer sounds to alert the front passenger that his
or her seat belt is not fastened. If the seat be lt is unfastened, the buzzer sounds intermittenly
for a certain period of time after the vehicle reaches a certain speed.
■Rear passengers’ seat belt reminder lights*1 (warning buzzer)*2
Warning lightDetails/Actions
(red)
or
(yellow)
Indicates a malfunction in the EPS (Electric Power Steering) system
Have the vehicle inspected by your Lexus dealer immediately.
Warning lightDetails/Actions
Indicates that remaining fuel is approximately 2.6 gal. (10 L, 2.2 Imp.
gal.) or less
 Refuel the vehicle.
Warning lightDetails/Actions
Warns the driver and/or front pass enger 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.
Warning lightDetails/Actions
Warns the rear passengers to fasten their seat belts
 Fasten the seat belt.

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).

3607-2. Steps to take in an emergency
1Locks all the doors
2 Unlocks the door
Turning the key rearward unlocks the
driver’s door. Turning the key once again
within 5 seconds unlocks the other doors.
■Trunk
Turn the mechanical key clockwise to
open. ( P.62)
■Key linked functions
1 Closes the windows and moon roof
(turn and hold)
*
2Opens the windows and moon roof
(turn and hold)
*
*
: This setting must be customized at your Lexus dealer.
1
Ensure that the shift lever is in P and
depress the brake pedal.
2 Touch the Lexus emblem side of the
electronic key to the engine switch.
When the electronic key is detected, a
buzzer sounds and the engine switch will
turn to IGNITION ON mode.
When the smart access system with
push-button start is deactivated in custom-
ization setting, the engine switch will turn
to ACCESSORY mode.
3 Firmly depress the brake pedal and
check that is shown on the
multi-information display.
4 Press the engine switch.
In the event that the engine still cannot
WARNING
■When using the mechanical key and
operating the power windows or
moon roof
Operate the power window or moon
roof after checking to make sure that
there is no possibility of any passenger
having any of their body parts caught in
the window or moon roof.
Also, do not allow children to operate the
mechanical key. It is possible for children
and other passengers to get caught in
the power window or moon roof.
Starting the engine

3637-2. Steps to take in an emergency
7
When trouble arises
IS300Positive (+) battery terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic poin t away from the battery and any mov-
ing parts as shown in the illustration
4 Start the engine of the second vehi-
cle. Increase the engine speed
slightly and maintain at that level for
approximately 5 minutes to
recharge the battery of your vehi-
cle.
5 Open and close any of the doors of
your vehicle with the engine switch
off.
6 Maintain the engine speed of the
second vehicle and start the engine
of your vehicle by turning the
engine switch to IGNITION ON
mode.
7 Once the vehicle’s engine has
started, remove the jumper cables
in the exact reverse order from
which they were connected.
Once the engine starts, have the vehi-
cle inspected at your Lexus dealer as
soon as possible.
■Starting the engine when the battery is
discharged
The engine cannot be started by push-start-
ing.
■To prevent battery discharge
●Turn off the headlights and the audio sys-
tem while the engine is off.
●Turn off any unnecessary electrical com-
ponents when the vehicle is running at a
low speed for an extended period, such
as in heavy traffic.
■Charging the battery
The electricity stored in the battery will dis-
charge gradually even when the vehicle is
not in use, due to natural discharge and the
draining effects of certain electrical appli-
ances. If the vehicle is left for a long time,
the battery may discharge, and the engine
may be unable to start. (The battery
recharges automatically during driving.)
■When recharging or replacing the bat-
tery
●In some cases, it may not be possible to
unlock the doors using the smart access
system with push-button start when the
battery is discharged. Use the wireless
remote control or the mechanical key to
lock or unlock the doors.
A
B
C
D