
5067-3. Do-it-yourself maintenance
RC300h_EE(OM24740E)
WARNING
■Proper inflation is critical to save tire performance
Keep your tires properly inflated. If the tires are not properly inflated, the following conditions may occur which could
lead to an accident resulting in death or serious injury:
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts resulting from overheated tires
●Air leaking from between tire and wheel
●Wheel deformation and/or tire damage
●Greater possibility of tire damage while driving (due to road hazards, expansion joints, sharp edges in the road, etc.)
NOTICE
■When inspecting and adjusting tire inflation pressure
Be sure to put the tire valve caps back on. If a valve cap is not installed, dirt or moisture may get into the valve and cause an airleak, resulting in decrease d tire inflation pressure.

5077-3. Do-it-yourself maintenance
7
Maintenance and care
RC300h_EE(OM24740E)
When replacing wheels, care should be taken to ensure that they are equivalent
to those removed in load capacity, diameter, rim width and inset*.
Replacement wheels are available at any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
*: Conventionally referred to as “offset”.
Lexus does not recommend using the following:
●Wheels of different sizes or types
●Used wheels
●Bent wheels that have been straightened
●Use only Lexus wheel nuts and wrenches designed for use with your alumi-
num wheels.
●When rotating, repairing or changing your tires, check that the wheel nuts are
still tight after driving 1600 km (1000 miles).
●Be careful not to damage the aluminum wheels when using tire chains.
●Use only Lexus genuine balance weights or equivalent and a plastic or rubber
hammer when balancing your wheels.
■When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and transmit- ters that allow the tire pressure warning sy stem to provide advance warning in the event
of a loss in tire inflation pressure. Whenever wheels are replaced, tire pressure warning valves and transmitters must be installed. (P. 486)
Wheels
If a wheel is bent, cracked or heavily corroded, it should be replaced. Other-
wise, the tire may separate from the wheel or cause a loss of handling control.
Wheel selection
Aluminum wheel precautions

5087-3. Do-it-yourself maintenance
RC300h_EE(OM24740E)
WARNING
■When replacing wheels
●Do not use wheels that are a different size from those recommended in the Owner’s Manual, as this may result in a loss of handling control.
●Never use an inner tube in a leaking wheel which is designed for a tubeless tire. Doingso may result in an accident, causing death or serious injury.
NOTICE
■Replacing tire pressure warning valves and transmitters
●Because tire repair or replacement may affe ct the tire pressure warning valves and
transmitters, make sure to have tires se rviced by any authorized Lexus dealer or repairer, or another duly qualified and equipped professional or other qualified ser-vice shop. In addition, make sure to purcha se your tire pressure warning valves and
transmitters at any authorized Lexus dealer or repairer, or another duly qualified and equipped professional.
●Ensure that only genuine Lexus wheels are used on your vehicle.
Tire pressure warning valves and transmitte rs may not work properly with non-genu- ine wheels.

527
8When trouble arises
RC300h_EE(OM24740E)
8-1. Essential information
Emergency flashers ..................528
If your vehicle has
to be stopped
in an emergency...................... 529
8-2. Steps to take
in an emergency
If your vehicle needs
to be towed................................530
If you think something
is wrong....................................... 536
If a warning light turns
on or a warning buzzer
sounds.......................................... 537
If a warning message
is displayed ................................ 542
If you have a flat tire .................. 563
If the hybrid system will
not start ....................................... 576
If the electronic key does
not operate properly ............. 578
If the 12-volt battery is
discharged .................................582
If your vehicle overheats ......... 587
If the vehicle becomes
stuck ............................................. 592

5348-2. Steps to take in an emergency
RC300h_EE(OM24740E)
■While towing
If the hybrid system is off, 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. 565)
WARNING
Observe the following precautions. Failure to do so may result in death or serious injury.
■When towing the vehicle
■While towing
●When towing using cables or chains, avoid sudden starts, etc. which place excessivestress on the towing eyelets, cables or ch ains. The towing eyelets, cables or chains may become damaged, broken debris ma y hit people, and cause serious damage.
●Do not turn the power switch off. There is a possibility that the steering wheel is locked and cannot be operated.
■Installing towing eyelets to the vehicle
Make sure that towing eyelets are installed securely. If not securely installed, towing ey elets may come loose during towing.
Be sure to transport the vehicle with all four wheels raised off the ground. If the vehicle is
towed with the tires contacting the ground, the drivetrain and related parts may be damaged,an accident may occur due to a change in
direction of the vehicle or electricity generated by the operation of the motor may cause a fireto occur depending on the nature of the dam-
age or malfunction.

5368-2. Steps to take in an emergency
RC300h_EE(OM24740E)
●Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
●Flat-looking tires or uneven tire wear
●Engine coolant temperature gauge continually points higher than normal.
●Changes in exhaust sound
●Excessive tire squeal when cornering
●Strange noises related to the suspension system
●Pinging or other noises related to the hybrid system
●Engine missing, stumbling or running roughly
●Appreciable loss of power
●Vehicle pulls heavily to one side when braking
●Vehicle pulls heavily to one side when driving on a level road
●Loss of brake effectiveness, spongy fe eling, pedal almost touches the floor
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact any authorized Lexus dealer or repairer, or
another duly qualified an d equipped professional as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

5398-2. Steps to take in an emergency
8
When trouble arises
RC300h_EE(OM24740E)
Automatic headlight leveling system warning light Indicates a malfunction in the au tomatic headlight leveling system
Have the vehicle inspected by any authorized Lexus dealer or repairer, or another duly qualified and equipped professionalimmediately.
Open door warning light (warning buzzer)*1
Indicates that a door or the trunk is not fully closed
Check that both side doors and the trunk are closed.
Low fuel level warning light Indicates that remaining fuel is approximately 10 L (2.6 gal., 2.2 Imp.gal.) or less
Refuel the vehicle.
Driver’s and front passenger’s seat belt reminder light (warning
buzzer)*2
Warns the driver and/or front passe nger 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.
Rear passengers’ seat belt reminder lights (warning buzzer)*2
Warns the rear passengers to fasten their seat belts Fasten the seat belt.
Master warning light A buzzer sounds and the warning light comes on and flashes to
indicate that the master warnin g system has detected a malfunc- tion. P. 542
Tire pressure warning light
When the light comes on: Low tire inflation pressure such as• Natural causes ( P. 540)
• Flat tire ( P. 563) Adjust the tire inflation pressure to the specified level. The light will turn off after a few minutes. If the warning light
does not turn off after a few minutes, perform initialization ( P. 487). If the light does not turn off after performing initialization,have the system checked by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
When the light comes on af ter blinking for 1 minute:
Malfunction in the tire pressure warning system Have the system checked by any authorized Lexus dealer or repairer, or another duly qualified and equipped professional.
Warning lightWarning light/Details/Actions

5408-2. Steps to take in an emergency
RC300h_EE(OM24740E)
*1: Open door warning buzzer:
P. 544
*2: Seat belt warning buzzer:
The seat belt warning buzzer sounds to al ert the driver, front passenger and rear pas- sengers that his or her seat belt is not fastened. The buzzer sounds for 30 seconds
after the vehicle reaches a speed of 20 km/h (12 mph). Then, if the seat belt is still unfastened, the buzzer will sound in a different tone for 90 more seconds.
■Front passenger detection sensor, seat belt reminder and warning buzzer
●If luggage is placed on a front passenger seat, the front passenger detection sensormay cause the warning light to flash and the warning buzzer to sound even if a passen-
ger is not sitting in the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the warn- ing light may not operate properly.
■If the malfunction indicator lamp comes on while driving
The malfunction indicator lamp will come on if the fuel tank becomes completely empty. If the fuel tank is empty, refuel the vehicle immediately. The malfunction indicator lamp
will go off after several trips.
If the malfunction indicator lamp does not go off, contact any authorized Lexus dealer or repairer, or another duly qualified and eq uipped professional as soon as possible.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insufficient 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
Carry out the following procedure after the tire temperature has lowered sufficiently.
●Check the tire inflation pressure and adjust to the appropriate level.
●If the warning light does not go out even afte r several minutes, check that the tire infla- tion pressure is at the specifie d level and carry out initialization.
The warning light may come on again if the above operations are conducted without first allowing the tire temperature to lower sufficiently.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air leaks and tire inflation pressure changes caused by temperature. In this case, adjustingthe tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with the spare tire (if equipped)
The spare tire is not equipped with a tire pre ssure warning valve and transmitter. If a tire
goes flat, the tire pressure warning light will no t turn off even though the flat tire has been replaced with the spare tire.
■Conditions that the tire pressure warning system may not function properly
P. 489