warning light LEXUS RX450h 2021 Service Manual

1674-1. Before driving
4
Driving
WARNING
●Do not shift the shift lever to a driving
position while the vehicle is moving
backward.
Doing so can damage the transmission
and may result in a loss of vehicle con-
trol.
●Shifting the shift lever to N while the
vehicle is moving will disengage the
hybrid system. Engine braking is not
available when N is selected.
●Be careful not to shift the shift lever
with the accelerator pedal depressed.
Shifting the shift lever to any position
other than P or N may lead to unex-
pected rapid acceleration of the vehi-
cle that may cause an accident and
result in death or serious injury.
■If you hear a squealing or scraping
noise (brake pad wear limit indica-
tors)
Have the brake pads checked and
replaced by your Lexus dealer as soon as
possible.
Rotor damage may result if the pads are
not replaced when needed.
It is dangerous to drive the vehicle when
the wear limits of the brake pads and/or
those of the brake discs are exceeded.
■When the vehicle is stopped
●Do not depress the accelerator pedal
unnecessarily.
If the shift lever is in any position other
than P or N, the vehicle may acceler-
ate suddenly and unexpectedly, caus-
ing an accident.
●In order to prevent accidents due to
the vehicle rolling away, always keep
depressing the brake pedal while
stopped with the “READY” indicator is
illuminated, and apply the parking
brake as necessary.
●If the vehicle is stopped on an incline,
in order to prevent accidents caused
by the vehicle rolling forward or back-
ward, always depress the brake pedal
and securely apply the parking brake
as needed.
●Avoid revving or racing the engine.
Running the engine at high speed
while the vehicle is stopped may cause
the exhaust system to overheat, which
could result in a fire if combustible
material is nearby.
■When the vehicle is parked
●Do not leave glasses, cigarette lighters,
spray cans, or soft drink cans in the
vehicle when it is in the sun.
Doing so may result in the following:
• Gas may leak from a cigarette lighter or spray can, and may lead to a fire.
• The temperature inside the vehicle may cause the plastic lenses and plas-
tic material of glasses to deform or
crack.
• Soft drink cans may fracture, causing the contents to spray over the interior
of the vehicle, and may also cause a
short circuit in the vehicle’s electrical
components.
●Do not leave cigarette lighters in the
vehicle. If a cigare tte lighter is in a
place such as the glove box or on the
floor, it may be lit accidentally when
luggage is loaded or the seat is
adjusted, causing a fire.
●Do not attach adhesive discs to the
windshield or windows. Do not place
containers such as air fresheners on
the instrument panel or dashboard.
Adhesive discs or containers may act
as lenses, causing a fire in the vehicle.
●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.

1764-1. Before driving
■GCWR (Gross Combination
Weight Rating)
The maximum allowable gross combi-
nation weight. The gross combination
weight is the sum of the total vehicle
weight (including the occupants, cargo
and any optional equipment installed
on the vehicle) and the weight of the
trailer being towed (including the
cargo in the trailer).
■GVWR (Gross Vehicle Weight
Rating)
The maximum allowable gross vehicle
weight. The gross vehicle weight is the
total weight of the vehicle. When tow-
ing a trailer, it is the sum of the vehicle
weight (including the occupants, cargo
and any optional equipment installed
on the vehicle) and the tongue weight.
WARNING
●Vehicle-trailer instabil ity is more likely
on steep long downhills. Before
descending steep or long downhill
grades, slow down and downshift. Do
not make sudden downshifts when
descending steep or long downhill
grades. Avoid holding the brake pedal
down too long or applying the brakes
too frequently. This could cause the
brakes to overheat and result in
reduced braking efficiency.
●Do not tow a trailer when the compact
spare tire is installed on your vehicle.
■When towing a trailer
Lexus recommends trailers with brakes
that conform to any applicable federal
and state/provincial regulations.
●If the gross trailer weight exceeds
unbraked TWR, trailer brakes are
required. Lexus recommends trailers
with brakes that conform to all applica-
ble federal and state/provincial regula-
tions.
●Never tap into your vehicle’s hydraulic
system, as this will lower the vehicle’s
braking effectiveness.
●Never tow a trailer without using a
safety chain securely attached to both
the trailer and the vehicle. If damage
occurs to the coupling unit or hitch
ball, there is danger of the trailer wan-
dering into another lane.
NOTICE
■When installing a trailer hitch
Use only the position recommended by
your Lexus dealer. Do not install the
trailer hitch on the bumper; this may
cause body damage.
■Do not directly splice trailer lights
Do not directly splice trailer lights.
Directly splicing trailer lights may dam-
age your vehicle’s electrical system and
cause a malfunction.
Towing related terms

1794-1. Before driving
4
Driving
Gross trailer weight
Tongue weight
Trailer hitch assemblies have different
weight capacities. Lexus recommends
the use of Lexus hitch/bracket for your
vehicle. For details, contact your Lexus
dealer.
 If you wish to install a trailer hitch,
contact your Lexus dealer.
 Use only a hitch that conforms to
the gross trailer weight requirement
of your vehicle.
 Follow the directions supplied by the
hitch manufacturer.
 Lubricate the hitch ball with a light
coating of grease.
 Remove the hitch ball whenever you
are not towing a trailer. Remove the
trailer hitch if you do not need it.
After removing the hitch, seal any
mounting hole in the vehicle body to
prevent entry of any substances into
the vehicle. Use the correct trailer ball for your
application.
Trailer ball load rating
Matches or exceeds the gross trailer
weight rating of the trailer.
Ball diameter
Matches the size of the trailer coupler.
Most couplers are stamped with the
required trailer ball size.
Hitch
A
B
WARNING
■Hitches
Trailer hitch assemblies have different
weight capacities established by the hitch
manufacturer. Even though the vehicle
may be physically capable of towing a
higher weight, the operator must deter-
mine the maximum weight rating of the
particular hitch assembly and never
exceed the maximum weight rating
specified for the trailer-hitch. Exceeding
the maximum weight rating set by the
trailer-hitch manufacturer can cause an
accident resulting in death or serious
personal injuries.
Selecting trailer ball
Trailer classTypical trailer ball size
IV2 5/16 in.
II and III2 in.
I1 7/8 in.
A
B

1864-2. Driving procedures
1Stop the vehicle completely.
2 Set the parking brake ( P.195),
and shift the shift lever to P.
3 Press the power switch.
4 Release the brake pedal and check
that the display on the meters is off.
■Automatic hybrid system shut off fea-
ture
●The vehicle is equipped with a feature
that automatically shuts off the hybrid sys-
tem when the shift lever is in P with the
hybrid system operating for an extended
period.
●The hybrid system will automatically shut
off after approximately 1 hour if it has
been left running while the shift lever is in
P.
●The timer for the automatic hybrid system
shut off feature will reset if the brake
pedal is depressed or if the shift lever is in
a position other than P.
●After the vehicle is parked, if the door is
locked with the door lock switch ( P.111)
from the inside or the mechanical key
from the outside, the automatic hybrid
system shut off feature will be disabled.
The timer for the automatic hybrid system
shut off feature will be re-enabled if the
driver’s door is opened.
■Locking the door from outside with the
hybrid system operating
1 With the driver’s door open, pull the
driver’s door hand le and insert the
mechanical key.
2 Turn the mechanical key counterclock-
wise.
3 Pull out the mechanical key and close
the door.NOTICE
■When starting the hybrid system
If the hybrid system becomes difficult to
start, have your vehicle checked by your
Lexus dealer immediately.
■Symptoms indicating a malfunction
with the power switch
If the power switch seems to be operat-
ing somewhat differently than usual, such
as the switch sticking slightly, there may
be a malfunction. Contact your Lexus
dealer immediately.
Stopping the hybrid system
WARNING
■Stopping the hybrid system in an
emergency
If you want to stop the hybrid system in an
emergency while driving the vehicle,
press and hold the power switch for more
than 2 seconds, or pr ess it briefly 3 times
or more in succession. ( P.410)
However, do not touch the power switch
while driving except in an emergency.
Turning the hybrid system off while driv-
ing will not cause loss of steering or brak-
ing control, however, power assist to the
steering will be lost. This will make it
more difficult to steer smoothly, so you
should pull over and stop the vehicle as
soon as it is safe to do so.

1964-2. Driving procedures
The parking brake indicator light and park-
ing brake light will turn on.
Pull and hold the parking brake switch if an
emergency occurs and it is necessary to
operate the parking brake while driving.
2Push the parking brake switch to
release the parking brake
Operate the switch while depressing the
brake pedal or slowly depressing the
accelerator pedal.
Make sure that the pa rking brake indicator
light and parking brake light turn off.
If the parking brake indicator light and
parking brake light flashes, operate the
switch again. ( P.424)
■Turns automatic mode on
While the vehicle is stopped, pull and
hold the parking brake switch until
“Automatic Mode On” will be dis-
played on the multi-information dis-
play.
When the automatic mode is turned
on, the parking brake operates as fol-
lows.
 When the shift lever is moved out of
P, the parking brake will be released,
and the parking brake indicator light
and parking brake light turn off.
 When the shift lever is moved into P,
the parking brake will be set, and the parking brake indicator light and
parking brake light turn on.
Operate the shift lever with the brake
pedal depressed.
■Turns automatic mode off
While the vehicle is stopped, press and
hold the parking brake switch until
“Automatic Mode Off” will be dis-
played on the multi-information dis-
play.
■Parking brake operation
●When the power swit ch is not in ON
mode, the parking brake cannot be
released using the parking brake switch.
●When the power swit ch is not in ON
mode, automatic mode (automatic brake
setting and releasing) is not available.
■Parking brake automatic release func-
tion
The parking brake is automatically released
when slowly depress the accelerator pedal.
The parking brake will be released auto-
matically under the following conditions:
• The driver’s door is closed.
• The driver’s seatbelt is fastened.
• Shift the shift lever is in a forward or reverse position.
• The malfunction indicator lamp or brake system warning light is not illuminated.
If the automatic release function does not
operate, manually release the parking
brake.

1974-2. Driving procedures
4
Driving
■If “Parking Brake Overheated Parking
Brake Unavailable” is displayed on the
multi-information display
If the parking brake is operated repeatedly
over a short period of time, the system may
restrict operation to prevent overheating. If
this happens, refrain from operating the
parking brake. Normal operation will return
after about 1 minute.
■If “EPB Activation Stopped Incom-
pletely” or “Parking Brake Unavailable”
is displayed on th e multi-information
display
Operate the parking brake switch. If the
message does not disappear after operat-
ing the switch several times, the system may
be malfunctioning. Have the vehicle
inspected by your Lexus dealer immedi-
ately.
■Parking brake operation sound
When the parking brake operates, a motor
sound (whirring sound) may be heard. This
does not indicate a malfunction.
■Parking brake indicator light and park-
ing brake light
●Depending on the power switch mode,
the parking brake in dicator light and
parking brake light will turn on and stay
on as described below:
ON mode: Comes on until the parking
brake is released.
Not in ON mode: Stays on for approxi-
mately 15 seconds.
●When the power switch is turned off with
the parking brake set, the parking brake
indicator light and parking brake light will
stay on for about 15 seconds. This does
not indicate a malfunction.
■Changing the mode
When changing the automatic mode on/off,
the message will be shown on the
multi-information display and the buzzer
sounds.
■Parking the vehicle
 P.164
■Parking brake engaged warning buzzer
A buzzer will sound if the vehicle is driven
with the parking brake engaged. “Release Parking Brake” is displayed on the
multi-information display.
■Warning messages and buzzers
Warning messages and buzzers are used to
indicate a system malfunction or to inform
the driver of the need for caution. If a warn-
ing message is shown on the multi-informa-
tion display, read the message and follow
the instructions.
■If the brake system warning light comes
on
 P.418
■Usage in winter time
 P.293
WARNING
■When parking the vehicle
Do not leave a child in the vehicle alone.
The parking brake may be released unin-
tentionally and there is the danger of the
vehicle moving that may lead to an acci-
dent resulting in death or serious injury.
■Parking brake switch
Do not set any objects near the parking
brake switch. Objects may interfere with
the switch and may lead the parking
brake to unexpectedly operate.
NOTICE
■When parking the vehicle
Before you leave the vehicle, shift the
shift lever to P, set the parking brake and
make sure that the vehicle does not
move.
■When the system malfunctions
Stop the vehicle in a safe place and
check the warning messages.

1984-2. Driving procedures
Turns the brake hold system on
The brake hold standby indicator (green) comes on. While the system is holding
the brake, the brake hold operated indica-
tor (yellow) comes on.
■Brake hold system operating conditions
The brake hold system cannot be turned on
in the following conditions:
●The driver’s door is not closed.
●The driver is not wearing the seat belt.
If any of the conditions above are detected
when the brake hold system is enabled, the
system will turn off and the brake hold
standby indicator light will go off. In addi-
tion, if any of the conditions are detected
while the system is holding the brake, a
warning buzzer will sound and a message
will be shown on the multi-information dis-
NOTICE
■When the parking brake cannot be
released due to a malfunction
Driving the vehicle with the parking
brake set will lead to brake components
overheating, which may affect braking
performance and increase brake wear.
Have the vehicle inspected by your
Lexus dealer immediately if this occurs.
Brake Hold
The brake hold system keeps the
brake applied when the shift lever is
in D, S or N with the system on and
the brake pedal has been
depressed to stop the vehicle. The
system releases the brake when the
accelerator pedal is depressed with
the shift lever in D or S to allow
smooth start off.
Enabling the system
A
B

1994-2. Driving procedures
4
Driving
play. The parking brake will then be set
automatically.
■Brake hold function
●If the brake pedal is left released for a
period of about 3 minutes after the sys-
tem has started holding the brake, the
parking brake will be set automatically. In
this case, a warning buzzer sounds and a
message is shown on the multi-informa-
tion display.
●To turn the system off while the system is
holding the brake, firmly depress the
brake pedal and press the button again.
●The brake hold function may not hold the
vehicle when the vehicle is on a steep
incline. In this situation, it may be neces-
sary for the driver to apply the brakes. A
warning buzzer will sound and the
multi-information display will inform the
driver of this situation. If a warning mes-
sage is shown on the multi-information
display, read the message and follow the
instructions.
■When the parking brake is set automati-
cally while the system is holding the
brakes
Perform any of the follo wing operations to
release the parking brake.
●Depress the accelerator pedal. (The
parking brake will not be released auto-
matically if the seat belt is not fastened.)
●Operate the parking brake switch with
the brake pedal depressed.
Make sure that the pa rking brake indicator
light goes off. ( P.195)
■When an inspection at your Lexus
dealer is necessary
When the brake hold standby indicator
(green) does not illuminate even when the
brake hold switch is pressed with the brake
hold system operating conditions met, the
system may be malfun ctioning. Have the
vehicle inspected at your Lexus dealer.
■If “Brake Hold Fault Depress Brake to
Deactivate Visit Your Dealer” or “Brake
Hold Malfunction Visit Your Dealer” is
displayed on the multi-information dis-
play
The system may be ma lfunctioning. Have
the vehicle inspected by your Lexus dealer.
■Warning messages and buzzers
Warning messages and buzzers are used to
indicate a system malfunction or to inform
the driver of the need for caution. If a warn-
ing message is shown on the multi-informa-
tion display, read the message and follow
the instructions.
■If the brake hold operated indicator
flashes
 P.425
WARNING
■When the vehicle is on a steep incline
When using the brake hold system on a
steep incline exercise caution. The brake
hold function may not hold the vehicle in
such a situation.
■When stopped on a slippery road
The system cannot stop the vehicle when
the gripping ability of the tires has been
exceeded. Do not use the system when
stopped on a slippery road.
NOTICE
■When parking the vehicle
The brake hold system is not designed
for use when parking the vehicle for a
long period of time. Turning the power
switch off while the system is holding the
brake may release the brake, which
would cause the vehicle to move. When
operating the power switch, depress the
brake pedal, shift the shift lever to P and
set the parking brake.

2034-3. Operating the lights and wipers
4
Driving
1Press the Automatic High Beam
switch.
2 Turn the headlight switch to the
or position.
The Automatic High Beam indicator will come on when the system is operating.
■Conditions to turn the high beams on/off
automatically
●When all of the follo
wing conditions are
met, the high beams will be turned on
automatically (after approximately 1 sec-
ond):
• The vehicle speed is approximately 21 mph (34 km/h) or more.
• The area ahead of the vehicle is dark.
• There are no vehicles ahead with head- lights or tail lights turned on.
• There are few streetlights on the road ahead.
●If any of the following conditions is met,
the high beams will turn off automatically:
• The vehicle speed is below approxi-
mately 17 mph (27 km/h).
• The area ahead of the vehicle is not dark.
• Vehicles ahead have their headlights or
tail lights turned on.
• There are many streetlights on the road ahead.
■Camera sensor dete ction information
●The high beams may not be automatically
turned off in the following situations:
• When a vehicle suddenly appears from around a curve
• When the vehicle is cut in front of by
another vehicle
• When vehicles ahead cannot be detected due to repeated curves, road
dividers or roadside trees
• When vehicles ahead appear in a far- away lane on a wide road
• When the lights of vehicles ahead are not
on
●The high beams may be turned off if a
vehicle ahead that is using fog lights with-
AHB (Automatic High
Beam)
The Automatic High Beam uses a
camera sensor located behind the
upper portion of the windshield to
assess the brightness of the lights of
vehicles ahead, streetlights, etc.,
and automatically turns the high
beams on or off as necessary.
WARNING
■Limitations of the Automatic High
Beam
Do not overly rely on the Automatic High
Beam. Always drive sa fely, taking care to
observe your surroundings and turning
the high beams on or off manually if nec-
essary.
■To prevent incorrect operation of the
Automatic High Beam system
Do not overload the vehicle.
Activating the Automatic High
Beam

2084-3. Operating the lights and wipers
●If the wiper switch is turned to the
“AUTO” position while the power switch
is in ON mode, the wipers will operate
once to show that AUTO mode is acti-
vated.
●When the sensor sensitivity ring is turned
toward high while in “AUTO” position, the
wipers will operate once to indicate that
the sensor sensitiv ity is enhanced.
●If the temperature of the raindrop sensor
is 194°F (90°C) or higher, or 5°F (-15°C)
or lower, automatic operation may not
occur. In this case, operate the wipers in
any mode other than AUTO mode.
■If no windshield washer fluid sprays
Check that the washer nozzles are not
blocked, if there is washer fluid in the
washer fluid tank.
■Front door opening linked windshield
wiper stop function
When “AUTO” is selected and the wind-
shield wipers are operatin g, if a front door is
opened, the operation of the windshield
wipers will be stopped to prevent anyone
near the vehicle from being sprayed by
water from the wipers, provided the vehicle
is stopped with the parking brake applied or
the shift lever in P. When the front door is
closed, wiper operation will resume.
■Customization
Some functions can be customized.
(  P.480)
When the windshield wipers are not
being used, they retract to below the
hood. To enable the windshield wipers
to be lifted when parking in cold condi-
tions or when replacing a windshield
wiper insert, change the rest position of
the windshield wipers to the service
position using the wiper lever.
WARNING
■Caution regarding the use of wind-
shield wipers in AUTO mode
The windshield wipers may operate
unexpectedly if the sensor is touched or
the windshield is subj ect to vibration in
A U T O m o d e . T a k e c a r e t h a t y o u r f i n g e r s ,
etc. do not become caught in the wind-
shield wipers.
■Caution regarding the use of washer
fluid
When it is cold, do not use the washer
fluid until the windshield becomes warm.
The fluid may freeze on the windshield
and cause low visibility. This may lead to
an accident, resulting in death or serious
injury.
NOTICE
■When the washer fluid tank is empty
Do not operate the switch continually as
the washer fluid pump may overheat.
■When a nozzle becomes blocked
In this case, contact your Lexus dealer.
Do not try to clear it with a pin or other
object. The nozzle will be damaged.
Changing the windshield wiper
rest position/Lifting the wind-
shield wipers