ECU LEXUS RC350 2021 Workshop Manual

2846-3. Do-it-yourself maintenance
WARNING
●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 light 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.

2867-1. Essential information
7-1.Essential information
Press the switch to flash all of the turn
signal lights.
To turn them off, press the switch once
again.
■Emergency flashers
If the emergency flashers are used for a
long time while the engine is not operating,
the battery may discharge.
1 Steadily step on the brake pedal
with both feet and firmly depress it.
Do not pump the brake pedal repeatedly
as this will increase the effort required to
slow the vehicle.
2Shift the shift lever to N.
If the shift lever is shifted to N
3 After slowing down, stop the vehi-
cle in a safe place by the road.
4 Stop the engine.
If the shift lever cannot be shifted to
N
3 Keep depressing the brake pedal
with both feet to reduce vehicle
speed as much as possible.
4 To stop the engine, press and hold
the engine switch for 2 consecutive
Emergency flashers
The emergency flashers are used to
warn other drivers when the vehicle
has to be stopped on the road due
to a breakdown, etc.
Operating instructions
If your vehicle has to be
stopped in an emergency
Only in an emergency, such as if it
becomes impossible to stop the
vehicle in the normal way, stop the
vehicle using the following proce-
dure:
Stopping the vehicle

2907-2. Steps to take in an emergency
The following may indicate a problem
with your transmission. Contact your
Lexus dealer or commercial towing
service before towing.
The engine is running but the vehi-
cle does not move.
 The vehicle makes an abnormal
sound.
From the front
Use a towing dolly under the rear
wheels.
WARNING
■While towing
●When towing using cables or chains,
avoid sudden starts, etc. which place
excessive stress on the towing eyelets,
cables or chains. The towing eyelets,
cables or chains may become dam-
aged, broken debris may hit people,
and cause serious damage.
●Do not turn the engine switch off.
There is a possibility that the steering
wheel is locked and cannot be oper-
ated.
■Installing towing eyelets to the vehi-
cle
Make sure that towing eyelets are
installed securely.
If not securely installed, towing eyelets
may come loose during towing.
NOTICE
■To prevent damage to the vehicle
when towing using a wheel-lift type
truck
●Do not tow the vehicle from the rear
when the engine switch is off. The
steering lock mechanism is not strong
enough to hold the front wheels
straight.
●When raising the vehicle, ensure ade-
quate ground clearance for towing at
the opposite end of the raised vehicle.
Without adequate clearance, the vehi-
cle could be damaged while being
towed.
■To prevent damage to the vehicle
when towing with a sling-type truck
Do not tow with a sling-type truck, either
from the front or rear.
■To prevent damage to the vehicle
during emergency towing
Do not secure cables or chains to the
suspension components.
■Recreational towing (behind motor
home, etc.)
Never dinghy tow your vehicle to pre-
vent causing serious damage to the
AWD system and transmission. ( P.126)

Situations when it is necessary to
contact dealers before towing
Towing with a wheel-lift type
truck

2917-2. Steps to take in an emergency
7
When trouble arises
From the rear
Use a towing dolly under the front
wheels.
When using a flat-bed truck to trans-
port the vehicle, use tire strapping
belts. Refer to the owner's manual of
the flat-bed truck for the tire strapping
method.
In order to suppress vehicle movement
during transportati on, set the parking
brake and turn the engine switch off.
If a tow truck is not available in an
emergency, your vehicle may be tem-
porarily towed using cables or chains secured to the emergency towing eye-
lets. This should only be attempted on
hard surfaced roads for at most 50
miles (80 km) at under 18 mph (30
km/h).
A driver must be in the vehicle to steer
and operate the brakes. The vehicle’s
wheels, drive train, axles, steering and
brakes must be in good condition.
To have your vehicle towed by another
vehicle, the towing eyelet must be
installed to your vehicle. Install the tow-
ing eyelet using the following proce-
dure.
1
Take out the wheel nut wrench, flat-
head screwdriver and towing eye-
let. ( P.307)
2 Remove the eyelet cover using a
flathead screwdriver.
To protect the bodywork, place a rag
between the screwdriver and the vehicle
body as shown in the illustration.
Except F SPORT models
 F SPORT models
NOTICE
■Towing with a sling-type truck
Do not tow with a sling-type truck to pre-
vent body damage.
Using a flatbed truck
Emergency towing
Emergency towing procedure

2927-2. 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 nut wrench
or hard metal bar.
5 Securely attach cables or chains to
the towing eyelet.
Take care not to damage the vehi-
cle body.
6 Enter the vehicle being towed and
start the engine.
If the engine does not start, turn the
engine switch to ON. 7
Shift the shift lever to N and release
the parking brake.
Turn automatic mode off. ( P.138)
When the shift lever cannot be shifted:
 P.132
■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 nut wrench
Wheel nut wrench is installed in trunk.
(  P.307)

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.

3097-2. Steps to take in an emergency
7
When trouble arises
1Hold the hook and lift up the lug-
gage mat.
2 Secure the luggage mat using the
hook. 3
Remove the tool tray.
4 Take out the jack.
1 For tightening
2 For loosening
If the jack is too tightly installed to be
removed by hand, insert a tool, such as the
screwdriver included wi th the vehicle, into
the hole of the jack (portion ) and
loosen the jack.
1 Secure the luggage mat using the
hook. ( P.309)
WARNING
●Do not raise the vehicle while some-
one is inside.
●When raising the vehicle, do not put an
object on or under the jack.
●Do not raise the vehicle to a height
greater than that required to replace
the tire.
●Use a jack stand if it is necessary to get
under the vehicle.
●When lowering the vehicle, make sure
that there is no-one near the vehicle. If
there are people nearby, warn them
vocally before lowering.
Taking out the jack
NOTICE
■To prevent damage to luggage mat
When closing the trunk lid, do not leave
the luggage mat lever hooked on the
edge of the trunk.
Taking out the spare tire
A

3107-2. Steps to take in an emergency
2Remove the tool tray.
3 Loosen the center fastener that
secures the spare tire.
If the center fastener cannot be turned by
hand, use the wheel nut wrench that is
stored in the trunk. (To secure the tire,
tighten the center fastener by hand. Do not
use the wrench or other tools.)
1 Chock the tires.
2 Slightly loosen the wheel nuts (one
turn).
3 Turn the tire jack portion by
hand until the notch of the jack is in
contact with the jack point.
The jack point guides are located under
the rocker panel. They indicate the jack
WARNING
■When storing the spare tire
Be careful not to catch fingers or other
body parts between the spare tire and
the body of the vehicle.
Replacing a flat tire
Flat tireWheel chock posi- tions
Front left-hand sideBehind the rear
right-hand side tire
Front right-hand
sideBehind the rear
left-hand side tire
Rear left-hand sideIn front of the front
right-hand side tire
Rear right-hand sideIn front of the front
left-hand side tire
A

3137-2. Steps to take in an emergency
7
When trouble arises
■When the spare tire is equipped
The vehicle becomes lower when driving
with the spare tire compared to when driv-
ing with standard tires.
■If you have a flat rear tire on a road cov-
ered with snow or ice (vehicles with
front and rear tires of the same size
except for vehicles with LDH and
19-inch tires)
Install the spare tire on one of the front
wheels of the vehicle. Perform the following
steps and fit tire chains to the rear tires:
1 Replace a front tire with the spare tire.
2 Replace the flat rear tire with the tire
removed from the front of the vehicle.
3 Fit tire chains to the rear tires.
WARNING
■When using the spare tire
●Remember that the spare tire provided
is specifically desi gned for use with
your vehicle. Do not use your spare
tire on another vehicle.
●Do not use more than one spare tire
simultaneously.
●Replace the spare tire with a standard
tire as soon as possible.
●Avoid sudden acceleration, abrupt
steering, sudden braking and shifting
operations that cause sudden engine
braking.
■When the spare tire is attached
The vehicle speed may not be correctly
detected, and the following systems may
not operate correctly:
• ABS & Brake assist
•VSC
•TRAC
• Dynamic radar cruise control with full-speed range
•PCS
•EPS
• Adaptive Variable Suspension System (if equipped)
• LDA (Lane Departure Alert with steering control)
• VGRS (if equipped)
• LDH (Lexus Dynamic Handling sys- tem) (if equipped)
• DRS (Dynamic Rear Steering) (if equipped)
• VDIM (Vehicle Dynamics Integrated Management)
• Tire pressure warning system
• Lexus parking assist monitor
• Intuitive parking assist (if equipped)
• Navigation system (if equipped)
Also, not only can the following system
not be utilized fully, bu t it may even nega-
tively affect the drive-train components:
• AWD system (if equipped)
■Speed limit when using the spare tire
Do not drive at speeds in excess of 50
mph (80 km/h) when a spare tire is
installed on the vehicle.
The spare tire is not designed for driving
at high speeds. Failure to observe this
precaution may lead to an accident caus-
ing death or serious injury.
■After using the tools and jack
Before driving, make sure all the tools
and jack are securely in place in their
storage location to reduce the possibility
of personal injury during a collision or
sudden braking.

3498-1. Specifications
8
Vehicle specifications
*: Table 1 - Occupant loading and distribution for vehicle normal load for various desig-
nated seating capacities
Radial ply tire
A pneumatic tire in which the ply cords that extend
to the beads are laid at su bstantially 90 degrees to
the centerline of the tread
Reinforced tire
A tire designed to operat e at higher loads and at
higher inflation pressures than the corresponding
standard tire
Section width
The linear distance between the exteriors of the
sidewalls of an inflated tire, excluding elevations
due to labeling, decoration, or protective bands
SidewallThat portion of a tire between the tread and bead
Sidewall separationThe parting of the rubber compound from the cord
material in the sidewall
Snow tire
A tire that attains a traction index equal to or
greater than 110, compared to the ASTM E-1136
Standard Referenc e Test Tire, when using the snow
traction test as described in ASTM F-1805-00,
Standard Test Method fo r Single Wheel Driving
Traction in a Straight Line on Snow-and Ice-Cov-
ered Surfaces, and which is marked with an Alpine
Symbol ( ) on at least one sidewall
Test rimThe rim on which a tire is fitted for testing, and may
be any rim listed as appropriate for use with that tire
TreadThat portion of a tire that comes into contact with
the road
Tread ribA tread section running ci rcumferentially around a
tire
Tread separationPulling away of the tread from the tire carcass
Treadwear indicators (TWI)
The projections within the principal grooves
designed to give a visual indication of the degrees
of wear of the tread
Wheel-holding fixtureThe fixture used to hold the wheel and tire assembly
securely during testing
Tire related termMeaning