2020 LEXUS RX450H warning light

6107-3. Do-it-yourself maintenance
RX350/RX350L_U
■Warning performance of the tire pressure warning system
The warning of the tire pressu re warning system will change in accordance with the con-
ditions under which it was init ialized. 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 initialized.
■When initialization of the tire pressure warning system has failed
Initialization may take longer to complete if the vehicle is driven on an unpaved road.
When performing initialization, drive on a pa ved road if possible. Depending on the driv-
ing environment and condition of the tires, initialization will be completed in approxi-
mately 10 to 30 minutes. If initialization is not complete after driving approximately 10 to
30 minutes, continue driving for a while.
If the inflation pressure of each tire is not displayed after driving for approximately 1 hour,
perform the following procedure.
●Park the vehicle in a safe place for approxim ately 20 minutes. Then drive straight (with
occasional left and right turns) at appr oximately 25 mph (40 km/h) or more for
approximately 10 to 30 minutes.
However, in the following situations, the tire inflation pressure will not be recorded and
the system will not operate proper ly. Perform initialization again.
●When operating the tire pressure warning reset switch, the tire pressure warning light
does not blink 3 times.
●After performing initia lization, the tire pressure warning light blinks for 1 minute then
stays on while driving.
If the inflation pressure of each tire is still not displayed, have the vehicle inspected by
your Lexus dealer.

6127-3. Do-it-yourself maintenance
RX350/RX350L_U
WARNING
■When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as dangerous han-
dling characteristics, which may lead to an accident resulting in death or serious injury.
●Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix differently constructed tires (radial, bias-belted or bias-ply tires).
●Do not mix summer, all season and snow tires.
●Do not use tires that have be en used on another vehicle.
Do not use tires if you do not know how they were used previously.
●Do not tow if your vehicle has a compact spare tire installed.
■When initializing the tire pressure warning system
Do not initializing tire inflatio n pressure without first adjusting the tire inflation pressure
to the specified level. Otherwise, the tire pressure warning light may not come on even
if the tire inflation pressure is low, or it may come on when the tire inflation pressure is
actually normal.
NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves, transmitters and
tire valve caps
●When removing or fitting the wheels, tires or the tire pressure warning valves and
transmitters, contact your Lexus dealer as the tire pressure warning valves and trans-
mitters may be damaged if not handled correctly.
●Make sure to install the tire valve caps. If the tire valve caps are not installed, water
could enter the tire pressure warning valves and the tire pressure warning valves
could be bound.
●When replacing tire valve caps, do not use tire valve caps other than those specified.
The cap may become stuck.
■To avoid damage to the tire pressu re warning valves and transmitters
When a tire is repaired with liquid sealants, the tire pressure warning valve and trans-
mitter may not operate properly. If a liquid sealant is used, contact your Lexus dealer or
other qualified service shop as soon as possible. Make sure to replace the tire pressure
warning valve and transmitter when replacing the tire. ( P. 605)
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause lo sses in tire inflation pressure, reducing the cushioning
ability of the tires. In addition, driving on rough roads may cause damage to the tires
themselves, as well as the vehicle’s wheels and body.
■If tire inflation pressure of ea ch tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

6267-3. Do-it-yourself maintenance
RX350/RX350L_U
Remove the fuse with the pullout
tool.
Only some fuses can be removed
using the pullout tool.
Check if the fuse is blown. Normal fuse
Blown fuse
Replace the blown fuse with a new
fuse of an appropriate amperage rat-
ing. The amperage rating can be
found on the fuse box lid.
Many types of fuse are used on this
vehicle. This illustration shows a com-
mon type of fuse used on this vehicle.
■After a fuse is replaced
●If the lights do not turn on even after the fuse has been replaced, a bulb may need
replacement. ( P. 630)
●If the replaced fuse blows again, have th e vehicle inspected by your Lexus dealer.
■If there is an overload in a circuit
The fuses are designed to blow, protecting the wiring harness from damage.
■When replacing light bulbs
Lexus recommends that you use genuine Lexus products designed for this vehicle.
Because certain bulbs are conne cted to circuits designed to prevent overload, nongenu-
ine parts or parts not designed for this vehicle may be unusable.
3
4
1
2
WARNING
■To prevent system breakdowns and vehicle fire
Observe the following precautions.
Failure to do so may cause damage to th e vehicle, and possibly a fire or injury.
●Never use a fuse of a higher amperage rating than that indicated, or use any other
object in place of a fuse.
●Always use a genuine Lexus fuse or equivalent.
Never replace a fuse with a wire, even as a temporary fix.
●Do not modify the fuses or fuse boxes.

6427-3. Do-it-yourself maintenance
RX350/RX350L_U
■LED lights
The headlight low beams, headlight high beams, front turn signal lights (vehicles with tri-
ple-beam headlights), parking lights and da ytime running lights, fog lights, cornering
lights (if equipped), front side marker lights (vehicles with triple-beam headlights), side
turn signal lights, stop/tail lights, rear turn signal light (vehicles with triple-beam head-
lights), rear side marker lights, high mounted stoplight, license plate lights, and outer foot
lights consist of a number of LEDs. If any of the LEDs has burned out, take your vehicle to
your Lexus dealer to have the light replaced.
■Condensation build-up on the inside of a lens
Temporary condensation build-up on the inside of the headlight lens does not indicate a
malfunction. Contact your Lexus dealer for mo re information in the following situations:
●Large drops of water have built up on the inside of a lens.
●Water has built up inside a headlight.
■When replacing light bulbs
P. 626
WARNING
■To prevent injury
Before performing any light bulb replacement procedure, be sure to turn the engine
switch off. Failure to do so may result in burns from hot components or a part of your
body may get caught on an operating co mponent, possibly causing serious injury.
■Replacing light bulbs
●Turn off the lights. Do not attempt to replac e 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 bu lb with bare hands. When it is unavoid-
able 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 sc ratched 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 th e headlight unit. This may damage the head-
lights or cause condensation to build up on the lens.
●Do not attempt to repair or disassemble th e light bulbs, connectors, electric circuits
or component parts.
Doing so may result in death or se rious injury due to electric shock.
■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.

643
8When trouble arises
RX350/RX350L_U
8-1. Essential informationEmergency flashers .................. 644
If your vehicle has to be stopped in
an emergency .......................... 645
8-2. Steps to take in an emergency
If your vehicle needs to be towed................................ 646
If you think something is wrong ........................................... 652
Fuel pump shut off system .......................................... 653
If a warning light turns on or a warning buzzer
sounds.......................................... 654
If a warning message is displayed...................................... 661
If you have a flat tire .................. 666
If the engine will not start ........ 682
If the electronic key does not operate properly .............684
If the vehicle battery is discharged ................................. 687
If your vehicle overheats ......... 692
If the vehicle becomes stuck ............................................. 695

6548-2. Steps to take in an emergency
RX350/RX350L_U
If a warning light turns on or a warning buzzer
sounds
Calmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, but then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspecte d by your Lexus dealer.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
(U.S.A.)
(Canada)
Brake system warning light Indicates that:
• The brake fluid level is low; or
• The brake system is malfunctioning
 Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
Brake system warning light
Indicates a malfunction in the electric parking brake
 Have the vehicle inspected by your Lexus dealer immediately.
(If equipped)
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
 Immediately stop the vehicle in a safe place and contact your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
(U.S.A.)
(Canada)
Malfunction indicator lamp Indicates a malfunction in:
• The electronic engine control system;
• The electronic throttle control system; or
• The electronic automatic transmission control system
 Have the vehicle inspected by your Lexus dealer immediately.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
 Have the vehicle inspected by your Lexus dealer immediately.
(U.S.A.)
(Canada)
ABS warning light Indicates a malfunction in:
• The ABS; or
• The brake assist system
 Have the vehicle inspected by your Lexus dealer immediately.

6558-2. Steps to take in an emergency
8
When trouble arises
RX350/RX350L_U
(Flashes)(U.S.A.)
(Flashes)
(Canada)
Parking brake indicator
It is possible that the parking br ake is not fully engaged or released
 Operate the parking brake switch once again.
This light comes on when the parking brake is not released. If the
light turns off after the parking brak e is fully released, the system is
operating normally.
(Flashes)
Brake hold operated indicator Indicates a malfunction in the brake hold system
 Have the vehicle inspected by your Lexus dealer immediately.
Electric power steering system warning light (warning buzzer)
Indicates a malfunction in the EPS (Electric Power Steering) sys-
tem
 Have the vehicle inspected by your Lexus dealer immediately.
LKA indicator
Indicates a malfunction in the LKA (Lane-Keeping Assist)
 When “Lane Keeping Assist Unavailable” is displayed on the
multi-information display, turn the LKA system off, drive the
vehicle for a short time, and then turn the LKA system back on.
(  P. 295)
When a message other than above is displayed, follow the
instructions displayed in the message.
Slip indicator When the warning lig ht is illuminated:
Indicates a malfunction in:
• The VSC system;
• The TRAC system;
• The Trailer Sway Control; or
• The hill-start assist control system
 Have the vehicle inspected by your Lexus dealer immediately.
When the warning light flashes:
Indicates that the VSC, TRAC or Trailer Sway Control system is
operating
Warning lightWarning light/Details/Actions

6568-2. Steps to take in an emergency
RX350/RX350L_U
(Flashes or illuminates)
PCS warning lightIndicates a malfunction in the PCS (Pre-Collision System) or that
the system is temporarily unavailable due to the vehicle being
extremely hot/cold, or dirt around a front sensor, etc.
( P. 290, 664)
 Follow the instructions displayed on the multi-information dis-
play. ( P. 290, 664)
If the PCS (Pre-Collision System ) or VSC (Vehicle Stability Con-
trol) system is disabled, the PC S warning light will illuminate.
 P. 290
(Flashes)
(If equipped)
ICS OFF indicator When a buzzer sounds:
Indicates a malfunction in the In telligent Clearance Sonar system
 Have the vehicle inspected by your Lexus dealer immediately.
When a buzzer does not sound:
Indicates that the system is temporarily unavailable, possibly due to
a sensor being dirty or covered with ice, etc.
 Clear the dirt, etc.
Low fuel level warning light
Indicates that remaining fuel is approximately 2.8 gal. (10.8 L,
2.3 Imp. gal.) or less
 Refuel the vehicle.
Driver’s and front passenger’s seat belt reminder light (warning
buzzer)
*1
Warns the driver and/or front passenger 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.
(RX350)
(RX350L)Rear passengers’ seat belt reminder light (warning buzzer)*2
Warns the rear passengers to fasten their seat belts
 Fasten the seat belt.
Tire pressure warning light
Indicates the following:
• Low tire pressure due to flat tire;
• Low tire pressure due to natural causes; or
• The tire pressure warnin g system is malfunctioning
 Immediately stop the vehicle in a safe place.
Handling method ( P. 658)
Warning lightWarning light/Details/Actions