check engine LEXUS RC350 2021 Service Manual

2756-3. Do-it-yourself maintenance
6
Maintenance and careUse only Lexus wheel nuts and
wrenches designed for use with
your aluminum wheels.
 When rotating, repairing or chang-
ing your tires, check that the wheel
nuts are still tight after driving 1000
miles (1600 km).
 Be careful not to damage the alumi-
num wheels when using tire chains.
 Use only Lexus genuine balance
weights or equivalent and a plastic
or rubber hammer when balancing
your wheels. 1
Turn 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.
WARNING
●Never use an inner tube in a leaking
wheel which is designed for a tubeless
tire. Doing so may result in an acci-
dent, causing death or serious injury.
NOTICE
■Replacing tire pressure warning
valves and transmitters
●Because tire repair or replacement
may affect the tire pressure warning
valves and transmitters, make sure to
have tires serviced by your Lexus
dealer or other qualified service shop.
In addition, make sure to purchase
your tire pressure warning valves and
transmitters at your Lexus dealer.
●Ensure that only ge nuine Lexus wheels
are used on your vehicle.
Tire pressure warning valves and trans-
mitters may not work properly with
non-genuine wheels.
Aluminum wheel precautions
Air conditioning filter
The air conditioning filter must be
changed regularly to maintain air
conditioning efficiency.
Removing the air conditioning
filter

2786-3. 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.
Left side instrument panel
Remove the lid.
WARNING
●Do not swallow the battery. Doing so
may cause chemical burns.
●A coin battery or button battery is
used in the electronic key. If a battery is
swallowed, it may cause severe chemi-
cal burns in as little as 2 hours and may
result in death or serious injury.
●Keep away new and removed batteries
from children.
●If the cover cannot be firmly closed,
stop using the electronic key and stow
the key in the place where children
cannot reach, and then contact your
Lexus dealer.
●If you accidentally swallow a battery or
put a battery into a part of your body,
get emergency medical attention
immediately.
■To prevent battery explosion or leak-
age of flammable liquid or gas
●Replace the battery with a new battery
of the same type. If a wrong type of
battery is used, it may explode.
●Do not expose batteries to extremely
low pressure due to high altitude or
extremely high temperatures.
●Do not burn, break or cut a battery.
NOTICE
■For normal operation after replacing
the battery
Observe the following precautions to
prevent accidents:
●Always work with dry hands.Moisture
may cause the battery to rust.
●Do not touch or move any other com-
ponent inside the remote control.
●Do not bend either of the battery ter-
minals.
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

2997-2. Steps to take in an emergency
7
When trouble arises
■Open door warning light (warning buzzer)*
*: Open door warning buzzer: P.90
■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 belt is unfastened, the buzzer sounds intermit-
tently for a certain period of time af ter the vehicle reaches a certain speed.
■Rear passengers’ seat belt reminder lights*1 (warning buzzer)*2
*1: This light illuminates on the center panel.
*2: Rear passengers’ seat belt warning buzzer:
Warning lightDetails/Actions
Indicates that a door or the trunk is not fully closed
 Check that both side doors and the trunk are closed.
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.

3017-2. Steps to take in an emergency
7
When trouble arises
■Brake hold operated indicator (warning buzzer)
■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.
■When the tire pressure warning light
comes on
Check the tire inflatio n pressure and adjust
to the appropriate leve l. Pushing the tire
pressure warning reset switch will not turn
off the tire pressure warning light.
■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.268
■If the tire pressure warning light fre-
quently comes on after blinking for 1
minute
If the tire pressure wa rning light frequently
comes on after blinking for 1 minute when
the engine switch is turned to IGNITION
ON mode, have it checked by your Lexus
dealer.
■Warning buzzer
In some cases, the buzzer may not be heard
due to being in a noisy location or audio
sound.
Warning lightDetails/Actions
(flashes)
Indicates a malfunction in the brake hold system
 Have the vehicle inspected by your Lexus dealer immediately.

3057-2. Steps to take in an emergency
7
When trouble arises
The warning lights and warning buzzers operate as follows depending on the con-
tent of the message. If a message indicates the need for inspection by a dealer, have
the vehicle inspected by your Lexus dealer immediately.
 In some situations, the master warning light and warning buzzer may not oper-
ate as specified. In this case, follow the instructions displayed in the warning
message.
 If a warning light comes on or flashes at the same time that a warning message is
displayed, take corrective actio n according to the warning light. ( P.295)
*: A buzzer sounds the first time a message is shown on the multi-information display.
■Warning messages
The warning messages explained below
may differ from the actual messages
according to operation conditions and vehi-
cle specifications.
■Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound.
■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.
■If a message that indicates the malfunc-
tion of front camera is displayed
The following systems may be suspended
until the problem shown in the message is
resolved. ( P.160, 298)
●PCS (Pre-Collision System)
●LDA (Lane Departure Alert with steering
control)
●Automatic High Beam
●Dynamic radar cruise control with
Messages and warnings
Warning buzzer*Warning
Comes onSounds
Indicates an important situat ion, such as when a sys-
tem related to driving is ma lfunctioning or that dan-
ger may result if the co rrection procedure is not
performed
FlashesSoundsIndicates a situation, such as when damage to the
vehicle or danger may result
Comes onDoes not sound
Indicates a condition, such as malfunction of electri-
cal components, their cond ition, or indicates the
need for maintenance
FlashesDoes not sound
Indicates a situation, such as when an operation has
been performed incorrectly, or indicates how to
perform an operation correctly

3067-2. Steps to take in an emergency
full-speed range
■If “Maintenance Required Soon” is dis-
played
Indicates that all maintenance according to
the driven distance on the maintenance
schedule
* should be performed soon.
Comes on approximately 4500 miles
(7200 km) after the message has been
reset. If necessary, perform maintenance.
Please reset the message after the mainte-
nance is performed. ( P.248)
*: Refer to the separa te “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.
■If “Maintenance Required Visit Your
Dealer” is displayed
Indicates that all maintenance is required to
correspond to the driven distance on the
maintenance schedule
*.
Comes on approximately 5000 miles
(8000 km) after the message has been
reset. (The indicator will not work properly
unless the message ha s been reset.) Per-
form the necessary maintenance. Please
reset the message after the maintenance is
performed. ( P.248)
*: Refer to the separa te “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.
■If “Oil Maintenance Required Soon” is
displayed
Indicates that the engine oil is scheduled to
be changed. (The indicator will not work
properly unless the oil maintenance data
has been reset.)
Check the engine oil, and change if neces-
sary. After changing the engine oil, the oil
change system should be reset. ( P.260)
■If “Oil Maintenance Required” is dis-
played
Indicates that the engine oil should be
changed. (After the engine oil is changed
and the oil maintenance data has been
reset.) Check and change the en
gine oil, and oil fil-
ter by your Lexus dealer. After changing the
engine oil, the oil change system should be
reset. ( P.260)
■If a message that indicates the need for
visiting your Lexus dealer is displayed
The system or part shown on the
multi-information display is malfunctioning.
Have the vehicle inspected by your Lexus
dealer immediately.
■If “See Owner’s Manual” is displayed
●If the following messages are shown, fol-
lowing the instruct ions, accordingly.
• “Engine Coolant Temp High” ( P.322)
●If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malfunction. Have the
vehicle inspected by your Lexus dealer
immediately.
• “Braking Power Low”
• “Access System with Elec. Key Malfunc-
tion”
●If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malfun ction. Immediately
stop the vehicle and contact your Lexus
dealer.
• “Oil Pressure Low”
• “Charging System Malfunction”
NOTICE
■“High Power Consumption Partial
Limit On AC/Heater Operation” is
frequently shown
There is a possible malfunction relating
to the charging system or the battery
may be deteriorating. Have the vehicle
inspected by your Lexus dealer.

3177-2. Steps to take in an emergency
7
When trouble arises
■When the electronic key does not work
properly
●Make sure that the smart access system
with push-button start has not been deac-
tivated in the customization setting. If it is
off, turn the function on.
●Check if battery-saving mode is set. If it is
set, cancel the function. ( P.96)
■Unlocking the door
Use the mechanical key ( P.84) in
order to perform the following opera-
tions: 1
Insert the mechanical key while
pulling on the driver’s door handle.
2 Unlocking the door.
3 Remove the key, return the handle,
and then pull the handle again.
■Locking the door
1 Move the inside lock button to the
lock position.
2 Close the door.
■Opening the trunk
Turn the mechanical key clockwise to
open. ( P.57)
If the electronic key does not
operate properly
If communication between the
electronic key and vehicle is inter-
rupted ( P.96) or the electronic
key cannot be used because the
battery is depleted, the smart
access system with push-button
start and wireless remote control
cannot be used. In such cases, the
doors and trunk can be opened and
the engine can be started by follow-
ing the procedure below.
NOTICE
■In case of a smart access system with
push-button start malfunction or
other key-related problems
Take your vehicle with all the electronic
keys provided with your vehicle, includ-
ing the card key, to your Lexus dealer.
Locking and unlocking the doors
and opening the trunk

3187-2. Steps to take in an emergency
■Key linked functions
1 Locks both side door
2 Closes the windows and moon roof (if
equipped) (turn and hold)
*
3Unlocks the door
Turning the key rearward unlocks the
driver’s door. Turning the key again unlocks
the other door.
4 Opens the windows and moon roof (if
equipped) (turn and hold)
*
*
: These settings 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
be started, contact your Lexus dealer.
■Stopping the engine
Shift the shift lever to P and press the engine
switch as you normally do when stopping
the engine.
■Electronic key battery
As the above procedure is a temporary
measure, it is recommended that the elec-
tronic key battery be replaced immediately
when the battery is depleted. ( P.277)
■Alarm (For Canada)
Using the mechanical ke y to lock the doors
will not set the alarm system.
If a door is unlocked using the mechanical
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 possibilit y of any passenger
having any of their body parts caught in
the window or moon roof.
Also, do not allow ch ildren 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

3247-2. Steps to take in an emergency
5Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
Engine (RC350/RC300 AWD)
 Engine (RC300)
 Intercooler (RC300)
6 Start the engine and turn the air
conditioning system on to check
that the radiator cooling fans oper-
ate and to check for coolant leaks
from the radiator or hoses.
The fans operate when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fans are oper- ating by checking the fan sound and air
flow. If it is difficult
to check these, turn the
air conditioning system on and off repeat-
edly.
(The fans may not oper ate in freezing tem-
peratures.)
7 If the fans are not operating:
Stop the engine immediately and
contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the
nearest Lexus dealer.
WARNING
■When inspecting under the hood of
your vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.
●Keep hands and clothing (especially a
tie, a scarf or a muffler) away from the
fans and belts. Failure to do so may
cause the hands or clothing to be
caught, resulting in serious injury.

3308-1. Specifications
■RC300
■Oil capacity (Drain and refill [Reference*])
*: The engine oil capacity is a reference quantity to be used when changing the engine oil. Warm up and turn off the engine, wait more than 5 minutes, and check the oil level on the
dipstick.
Displacement210.9 cu. in. (3456 cm3)
Drive belt tensionAutomatic adjustment
Model2.0 L 4-cylinder (8AR-FTS) engine
Type4-cylinder in line, 4-cycle, gasoline (with tur-
bocharger)
Bore and stroke3.39  3.39 in. (86.0  86.0 mm)
Displacement121.9 cu. in. (1998 cm3)
Drive belt tensionAutomatic adjustment
Fuel
Fuel typeUnleaded gasoline only
Octane Rating91 (Research Octane Number 96) or higher
Fuel tank capacity (Reference)17.5 gal. (66.4 L, 14.6 Imp. gal.)
Lubrication system
With filter
RC350
6.0 qt. (5.7 L, 5.0 Imp. qt.)
RC350 AWD/RC300 AWD
6.8 qt. (6.4 L, 5.6 Imp. qt.)
RC300
4.9 qt. (4.6 L, 4.0 Imp. qt.)
Without filter
RC350
5.8 qt. (5.5 L, 4.8 Imp. qt.)
RC350 AWD/RC300 AWD
6.3 qt. (6.0 L, 5.3 Imp. qt.)
RC300
4.5 qt. (4.3 L, 3.8 Imp. qt.)