ECU LEXUS RC300 2020 Service Manual

1204-1. Before driving
WARNING
●Do not leave a door or window open if
the curved glass is coated with a met-
allized film such as a silver-colored
one. Reflected sunlight may cause the
glass to act as a lens, causing a fire.
●Always apply the parking brake, shift
the shift lever to P, stop the engine and
lock the vehicle.
Do not leave the vehicle unattended
while the engine is running.
If the vehicle is parked with the shift
lever in P but the parking brake is not
set, the vehicle may start to move, pos-
sibly leading to an accident.
●Do not touch the exhaust pipes while
the engine is running or immediately
after turning the engine off.
Doing so may cause burns.
■When taking a nap in the vehicle
Always turn the engine off. Otherwise, if
you accidentally move the shift lever or
depress the accelerator pedal, this could
cause an accident or fire due to engine
overheating. Additionally, if the vehicle is
parked in a poorly ventilated area,
exhaust gases may collect and enter the
vehicle, leading to death or a serious
health hazard.
■When braking
●When the brakes are wet, drive more
cautiously.
Braking distance increases when the
brakes are wet, and this may cause one
side of the vehicle to brake differently
than the other side. Also, the parking
brake may not securely hold the vehi-
cle.
●If the brake booster device does not
operate, do not follow other vehicles
closely and avoid hills or sharp turns
that require braking.
In this case, braking is still possible, but
the brake pedal should be depressed
more firmly than usual. Also, the brak-
ing distance will increase. Have your
brakes fixed immediately.
●Do not pump the brake pedal if the
engine stalls.
Each push on the brake pedal uses up
the reserve for the power-assisted
brakes.
●The brake system consists of 2 individ-
ual hydraulic systems; if one of the sys-
tems fails, the other w ill still operate. In
this case, the brake pedal should be
depressed more firmly than usual and
the braking distance will increase.
Have your brakes fixed immediately.
■If the vehicle becomes stuck
Do not spin the wheels excessively when
any of the tires is up in the air, or the vehi-
cle is stuck in sand, mud, etc. This may
damage the driveline components or
propel the vehicle forward or backward,
causing an accident.
NOTICE
■When driving the vehicle
●Do not depress the accelerator and
brake pedals at th e same time while
driving, as this may restrain the engine
output.
●Do not use the accelerator pedal or
depress the accelerator and brake
pedals at the same time to hold the
vehicle on a hill.
■When parking the vehicle
Always set the parking brake and shift
the shift lever to P. Failure to do so may
cause the vehicle to move or the vehicle
may accelerate suddenly if the accelera-
tor pedal is accidentally depressed.
■Avoiding damage to vehicle parts
●Do not turn the steering wheel fully in
either direction and hold it there for an
extended period of time. Doing so may
damage the power steering motor.
●When driving over bumps in the road,
drive as slowly as possible to avoid
damaging the wheels, underside of the
vehicle, etc.

1234-1. Before driving
4
Driving
■Total load capacity and seating capacity
These details are also described on the tire
and loading information label. ( P.263)
WARNING
●To prevent cargo and luggage from
sliding forward during braking, do not
stack anything in th e enlarged trunk.
Keep cargo and luggage low, as close
to the floor as possible.
●When you fold down the rear seats,
long items should not be placed
directly behind the front seats.
●Never allow anyone to ride in the
enlarged trunk. It is not designed for
passengers. They should ride in their
seats with their seat belts properly fas-
tened.
●Do not place cargo or luggage in or on
the following locations.
• At the feet of the driver
• On the front passenger or rear seats (when stacking items)
• On the package tray
• On the instrument panel
• On the dashboard
• In front of the Center Display
●Secure all items in the occupant com-
partment.
■Capacity and distribution
●Do not exceed the maximum axle
weight rating or the total vehicle
weight rating.
●Even if the total load of occupant’s
weight and the cargo load is less than
the total load capacity, do not apply the
load unevenly. Improper loading may
cause deterioration of steering or
braking control which may cause
death or serious injury.
Vehicle load limits
Vehicle load limits include total
load capacity, seating capacity,
towing capacity and cargo capac-
ity.
 Total load capacity (vehicle
capacity weight):  P.318
Total load capacity means the com-
bined weight of occupants, cargo
and luggage.
 Seating capacity: 4 occupants
(Front 2, Rear 2)
Seating capacity means the maxi-
mum number of occupants whose
estimated average weight is 150 lb.
(68 kg) per person.
 Towing capacity
Lexus does not recommend towing
a trailer with your vehicle.
 Cargo capacity
Cargo capacity may increase or
decrease depending on the weight
and the number of occupants.
WARNING
■Overloading the vehicle
Do not overload the vehicle.
It may not only cause damage to the tires,
but also degrade steering and braking
ability, resulting in an accident.

1254-2. Driving procedures
4
Driving
4-2.Driving procedures
1Check that the parking brake is set.
2 Check that the shift lever is in P.
3 Firmly depress the brake pedal.
and a message will be displayed on
the multi-information display.
If it is not displayed, the engine cannot be
started.
4 Press the engine switch shortly and
firmly.
When operating the engine switch, one
short, firm press is enough.
It is not necessary to press and hold the
switch.
The engine will crank until it starts or for up
to 30 seconds, whichever is less.
Continue depressing the brake pedal until
the engine is completely started.
The engine can be started from any engine
switch mode.
■If the engine does not start
●The engine immobilizer system may not have been deactivated. (
P.56)
Contact your Lexus dealer.
●Check that the shift leve r is securely set in
P. The engine may not start if the shift
lever is displaced out of P. “To Start Vehi-
cle. Put Shift Lever into P” will be dis-
played on the multi-information display.
■Electronic key battery depletion
 P.82
■Conditions affecting operation
 P.94
■Notes for the entry function
 P.95
■Steering lock function
●After turning the engine switch off and
opening and closing the doors, the steer-
ing wheel will be lock ed due to the steer-
ing lock function. Operating the engine
switch again automatically cancels the
steering lock.
●When the steering lock cannot be
released, “Steering Wheel Lock Press
Engine Switch while Turning Wheel” will
be displayed on the multi-information dis-
play.
Check that the shift lever is in P. Press the
engine switch while turning the steering
wheel left and right.
●To prevent the steering lock motor from
overheating, operation of the motor may
be suspended if the engine is turned on
and off repeatedly in a short period of
time. In this case, refrain from operating
the engine switch. After about 10 sec-
onds, the steering lock motor will resume
functioning.
Engine (ignition) switch
Performing the following opera-
tions when carryin g the electronic
key on your person starts the
engine or changes engine switch
modes.
Starting the engine

1494-4. Refueling
4
Driving
4-4.Refueling
Close both side doors and windows,
and turn the engine switch off.
 Confirm the type of fuel.
■Fuel types
 P.329
■Fuel tank opening for unleaded gasoline
To help prevent incorrect fueling, your vehi-
cle has a fuel tank opening that only accom-
modates the special nozzle on unleaded
fuel pumps.
■If the malfunction indicator lamp illumi-
nates
The malfunction indicator lamp may illumi-
nate erroneously if refueling is performed
repeatedly when the fuel tank is nearly full.
Opening the fuel tank cap
Perform the following steps to open
the fuel tank cap:
Before refueling the vehicle
WARNING
■When refueling the vehicle
Observe the following precautions while
refueling the vehicle. Failure to do so may
result in death or serious injury.
●After exiting the vehicle and before
opening the fuel door, touch an
unpainted metal surface to discharge
any static electricity. It is important to
discharge static electricity before refu-
eling because sparks resulting from
static electricity can cause fuel vapors
to ignite while refueling.
●Always hold the grips on the fuel tank
cap and turn it slowly to remove it.
A whooshing sound may be heard
when the fuel tank cap is loosened.
Wait until the sound cannot be heard
before fully removing the cap. In hot
weather, pressurized fuel may spray
out the filler neck and cause injury.
●Do not allow anyone that has not dis-
charged static electricity from their
body to come close to an open fuel
tank.
●Do not inhale vaporized fuel.
Fuel contains substances that are
harmful if inhaled.
●Do not smoke while refueling the vehi-
cle.
Doing so may cause the fuel to ignite
and cause a fire.
●Do not return to the vehicle or touch
any person or object that is statically
charged.
This may cause static electricity to
build up, resulting in a possible ignition
hazard.
■When refueling
Observe the following precautions to
prevent fuel overflowing from the fuel
tank:
●Securely insert the fuel nozzle into the
fuel filler neck.
●Stop filling the tank after the fuel noz-
zle automatically clicks off.
●Do not top off the fuel tank.
NOTICE
■Refueling
Do not spill fuel during refueling. Doing
so may damage the vehicle, such as
causing the emission control system to
operate abnormally or damaging fuel
system components or the vehicle’s
painted surface.

1884-5. Using the driving support systems
●The vehicle speed is greater than approx-
imately 10 mph (16 km/h).
■The BSM function will detect a vehicle
when
The BSM function will detect a vehicle pres-
ent in the detection area in the following sit-
uations:
●A vehicle in an adj acent lane overtakes
your vehicle.
●You overtake a vehicle in an adjacent lane
slowly.
●Another vehicle enters the detection
area when it changes lanes.
■Conditions under which the BSM func-
tion will not detect a vehicle
The BSM function is not designed to detect
the following types of vehicles and/or
objects:
●Small motorcycles, bicycles, pedestrians,
etc.*
●Vehicles traveling in the opposite direc-
tion
●Guardrails, walls, signs, parked vehicles
and similar stationary objects*
●Following vehicles th at are in the same
lane*
●Vehicles traveling 2 lanes away from your
vehicle*
●Vehicles which are being overtaken rap-
idly by your vehicle*
*
: Depending on the conditions, detection of a vehicle and/or object may occur.
■Conditions under which the BSM func-
tion may not function correctly
●The BSM function may not detect vehi-
cles correctly in the following situations:
• When the sensor is misaligned due to a strong impact to the sensor or its sur-
rounding area
• When mud, snow, ice, a sticker, etc. is covering the sensor or surrounding area
on the rear bumper
• When driving on a road surface that is wet with standing water during bad
weather, such as heavy rain, snow, or fog • When multiple vehicles are approaching
with only a small gap between each vehi-
cle
• When the distance between your vehicle and a following vehicle is short
• When there is a significant difference in
speed between your vehicle and the vehi-
cle that enters the detection area
• When the difference in speed between
your vehicle and another vehicle is
changing
• When a vehicle enters a detection area
traveling at about the same speed as your
vehicle
• As your vehicle starts from a stop, a vehi-
cle remains in the detection area
• When driving up and down consecutive steep inclines, such as hills, dips in the
road, etc.
• When driving on roads with sharp bends, consecutive curves, or uneven surfaces
• When vehicle lanes are wide, or when driving on the edge of a lane, and the
vehicle in an adjacent lane is far away
from your vehicle
• When a bicycle carrier or other acces- sory is installed to the rear of the vehicle
• When there is a significant difference in height between your vehicle and the
vehicle that enters the detection area
• Immediately after the BSM main switch is turned on
●Instances of the BSM function unneces-
sarily detecting a vehicle and/or object
may increase in the following situations:
• When the sensor is misaligned due to a strong impact to the sensor or its sur-
rounding area
• When the distance between your vehicle and a guardrail, wall, etc. that enters the
detection area is short
• When driving up and down consecutive steep inclines, such as hills, dips in the
road, etc.
• When vehicle lanes are narrow, or when driving on the edge of a lane, and a vehi-
cle traveling in a lane other than the adja-
cent lanes enters the detection area
• When driving on roads with sharp bends, consecutive curves, or uneven surfaces
• When the tires are slipping or spinning
• When the distance between your vehicle
and a following vehicle is short
• When a bicycle carrier or other acces-

2215-4. Using the storage features
5
Interior features
Raise the hooks when needed.
The cargo hooks are provided for securing
loose items.
1Loosen the belt
2
Tighten the belt
Trunk features
Cargo hooks
WARNING
■When the cargo net is not in use
To avoid injury, always return the cargo
hooks on the floor to their stowed posi-
tions.
First-aid kit storage belt

2245-5. Using the other interior features
The HomeLink® wireless control sys-
tem in your vehicle has 3 buttons which
can be programmed to operate 3 dif-
ferent devices. Refer to the program-
ming methods on the following pages
to determine the method which is
appropriate for the device.
HomeLink
® indicator light
Garage door operation indicators
HomeLink
® icon
Illuminates while HomeLink® is operating.
Buttons
■Codes stored in the HomeLink® mem-
ory
●The registered codes are not erased even
if the battery cable is disconnected.
●If learning failed wh en registering a dif-
ferent code to a HomeLink® button that
already has a code registered to it, the already registered code will not be
erased.
■When support is necessary
Visit on the web at
www.homelink.com/lexus
or call
1-800-355-3515.
■Before programming HomeLink®
 During programming, it is possible
that garage doors, gates, or other
devices may operate. For this rea-
son, make sure that people and
objects are clear of the garage door
or other devices to prevent injury or
other potential harm.
 It is recommended that a new bat-
Garage door opener
The garage door opener can be
programmed to operate garage
doors, gates, entry doors, door
locks, home lighting systems, secu-
rity systems, and other devices.
System components
A
B
C
D
WARNING
■When programming a garage door or
other remote control device
The garage door or other device may
operate, so ensure people and objects
are out of danger to prevent potential
harm.
■Conforming to federal safety stan-
dards
Do not use the HomeLink
® compatible
transceiver with any garage door opener
or device that lacks safety stop and
reverse features as required by federal
safety standards.
This includes any garage door that can-
not detect an interf ering object. A door
or device without these features
increases the risk of death or serious
injury.
■When operating or programming
HomeLink®
Never allow a child to operate or play
with the HomeLink® buttons.
Programming the HomeLink®

2315-5. Using the other interior features
5
Interior features
If there is not enough space to drive in a
circle, drive around the block until the
direction is displayed.
WARNING
■When doing the circling calibration
Secure a wide space, and watch out for
people and vehicles in the neighbor-
hood. Do not violate any local traffic
rules while performi ng circling calibra-
tion.

2426-2. Maintenance
Radiator, con-
denser and inter-
cooler radiator
The radiator, con-
denser and inter-
cooler radiator should
be free from foreign
objects. (P.254)
Washer fluid
Is there sufficient
washer fluid?
( P.256)
Vehicle interior
ItemsCheck points
Accelerator
pedal
• The accelerator
pedal should move
smoothly (without
uneven pedal effort
or catching).
Automatic trans-
mission “Park”
mechanism
•When parked on a slope and the shift
lever is in P, is the
vehicle securely
stopped?
Brake pedal
• Does the brake pedal move
smoothly?
• Does the brake pedal have appro-
priate clearance
from the floor?
• Does the brake pedal have the cor-
rect amount of free
play?
ItemsCheck points
Brakes
• The vehicle should not pull to one side
when the brakes are
applied.
•The brakes should work effectively.
• The brake pedal should not feel
spongy.
• The brake pedal should not get too
close to the floor
when the brakes are
applied.
Head restraints
•Do the head restraints move
smoothly and lock
securely?
Indicators/buzz-
ers•Do the indicators and buzzers function
properly?
Lights• Do all the lights come on?
Parking brake
• Does the parking brake pedal move
smoothly?
• When parked on a slope and the park-
ing brake is on, is the
vehicle securely
stopped?
Seat belts
• Do the seat belts operate smoothly?
• The seat belts should not be damaged.
ItemsCheck points

2746-3. Do-it-yourself maintenance
there is no light leaking from the bulb base.
8Align the tabs and push the light
unit toward the front of the vehicle
to install it.
9
Install the 2 screws and cover.
1
0Remove the protective tape.
WARNING
■Replacing light bulbs
●Turn off the lights. Do not attempt to
replace 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 bulb with bare hands. When it is
unavoidable 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 scratched 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 the lig ht unit. This may
damage the lights or cause condensa-
tion 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.