warning light LEXUS RC350 2019 Repair Manual

2536-3. Do-it-yourself maintenance
RC350AWD_RC350_RC300AWD_RC30
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6
Maintenance and care
■Brake fluid can absorb moisture from
the air
Excess moisture in the brake fluid can cause
a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
Check the battery as follows.
■Battery exterior
Make sure that the battery terminals
are not corroded and that there are no
loose connections, cracks, or loose
clamps. Terminals
Hold-down clamp
■Before recharging
When recharging, the battery produces
hydrogen gas which is flammable and
explosive. Therefore, observe the following
before recharging:
●If recharging with the battery installed on
the vehicle, be sure to disconnect the
ground cable.
●Make sure the power switch on the char-
ger is off when connecting and discon-
necting the charger cables to the battery.
■After recharging/reconnecting the bat-
tery
The engine may not start. Follow the proce-
dure below to initialize the system.
1
Shift the shift lever to P.
2
Open and close either door.
3
Restart the engine.
●Unlocking the doors using the smart
access system with pu sh-button start may
not be possible immediately after recon-
necting the battery. If this happens, use
the wireless remote control or the
mechanical key to lock/unlock the doors.
●Start the engine with the engine switch in
ACCESSORY mode. The engine may
not start with the engine switch turned off.
However, the engine will operate nor-
mally from the second attempt.
●The engine switch mode is recorded by
the vehicle. If the battery is disconnected
and reconnected, the vehicle will return
the engine switch mode to the status it
was in before the battery was discon-
nected. Make sure to turn off the engine
before disconnecting the battery. Take
extra care when connecting the battery if
the engine switch mode prior to the bat-
tery being disconnected is unknown.
If the system will not start even after multi-
ple attempts, contact your Lexus dealer.
WARNING
■When filling the reservoir
Take care as brake fluid can harm your
hands and eyes and damage painted sur-
faces.If fluid gets on your hands or in your
eyes, flush the affected area with clean
water immediately.
If you still experience discomfort, see a
doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go
down slightly as the brake pads wear out
or when the fluid level in the accumulator
is high.
If the reservoir need s frequent refilling,
there may be a serious problem.
Battery
A
B

2546-3. Do-it-yourself maintenance
RC350AWD_RC350_RC300AWD_RC30
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If any washer does not work or the
warning message appears on the
multi-information display, the washer
tank may be empty. Add washer fluid.
RC350/RC300 AWD
WARNING
■Chemicals in the battery
Batteries contain poisonous and corro-
sive sulfuric acid and may produce
hydrogen gas which is flammable and
explosive. To reduce the risk of death or
serious injury, take the following precau-
tions while working on or near the bat-
tery:
●Do not cause sparks by touching the
battery terminals with tools.
●Do not smoke or light a match near the
battery.
●Avoid contact with eyes, skin and
clothes.
●Never inhale or swallow electrolyte.
●Wear protective safety glasses when
working near the battery.
●Keep children away from the battery.
■Where to safely charge the battery
Always charge the battery in an open
area. Do not charge the battery in a
garage or closed room where there is
insufficient ventilation.
■How to recharge the battery
Only perform a slow charge (5 A or
less). The battery may explode if charged
at a quicker rate.
■Emergency measures regarding
electrolyte
●If electrolyte gets in your eyes
Flush your eyes with clean water for at
least 15 minutes and get immediate med-
ical attention. If possible, continue to
apply water with a sponge or cloth while
traveling to the nearest medical facility.
●If electrolyte gets on your skin
Wash the affected area thoroughly. If you
feel pain or burning, get medical atten-
tion immediately.
●If electrolyte gets on your clothes
It can soak through clothing on to your
skin. Immediately take off the clothing
and follow the procedure above if neces-
sary.
●If you accidentally swallow electrolyte
Drink a large quantity of water or milk.
Get emergency medical attention imme-
diately.
NOTICE
■When recharging the battery
Never recharge the battery while the
engine is running. Also, be sure all acces-
sories are turned off.
Adding the washer fluid

2586-3. Do-it-yourself maintenance
RC350AWD_RC350_RC300AWD_RC30
0_OM_(U)_1810information will not be updated.
If this accidentally oc
curs, either turn the
engine switch to off and then to IGNITION
ON mode, or initialize the system after
checking that the tire pressure is properly
adjusted.
Your vehicle is equipped with a tire
pressure warning system that uses tire
pressure warning valves and transmit-
ters to detect low tire inflation pressure
before serious problems arise.
 If the tire pressure drops below a
predetermined level, the driver is
warned by a screen display and a
warning light. ( P.287)
 The tire pressure detected by the
tire pressure warning system can be
displayed on the multi-information
display. ( P.71)
The illustration used is intended as an
example, and may differ from the image
that is actually displayed on the multi-infor-
mation display.
■Routine tire inflation pressure checks
The tire pressure warning system does not
replace routine tire inflation pressure
checks. Make sure to check tire inflation
pressure as part of your routine of daily
vehicle checks.
■Situations in which the tire pressure
warning system may not operate prop-
erly
●In the following cases, the tire pressure
warning system may not operate prop-
erly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains, etc. are equipped.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects the radio wave signals is installed.
• If there is a lot of snow or ice on the vehi-
cle, particularly around the wheels or
wheel housings.
• If the tire inflation pressure is extremely
higher than the specified level.
• If tires not equipped with tire pressure warning valves and transmitters are used.
• If the ID code on the tire pressure warn- ing valves and transmitters is not regis-
tered in the tire pressure warning
computer.
●Performance may be af fected in the fol-
lowing situations.
• Near a TV tower, electric power plant, gas station, radio stat ion, large display,
airport or other fac ility that generates
strong radio waves or electrical noise
• When carrying a portable radio, cellular
phone, cordless phone or other wireless
communication device
If tire position information is not correctly
displayed due to the radio wave conditions,
the display may be corrected by driving and
changing the radio wave conditions.
●When the vehicle is parked, the time
taken for the warning to start or go off
could be extended.
●When tire inflation pr essure declines rap-
idly for example when a tire has burst, the
warning may not function.
Tire pressure warning system

2596-3. Do-it-yourself maintenance
RC350AWD_RC350_RC300AWD_RC30
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6
Maintenance and care
When replacing tires or wheels, tire
pressure warning valves and transmit-
ters must also be installed.
When new tire pressure warning
valves and transmitte rs are installed,
new ID codes must be registered in the
tire pressure warning computer and
the tire pressure warning system must
be initialized. Have tire pressure warn-
ing valve and transmitter ID codes reg-
istered by your Lexus dealer. ( P.261)
■Replacing tires and wheels
If the ID code of the tire pressure warning
valve and transmitter is not registered, the
tire pressure warning system will not work
properly. After driving for about 20 min-
utes, the tire pressure warning light blinks
for 1 minute and stays on to indicate a sys-
tem malfunction.WARNING
■Caution regarding interference with
electronic devices
●People with implantable cardiac pace-
makers, cardiac resynchronization
therapy-pacemakers or implantable
cardioverter defibrillators should not
come within 17.7 in . (450 mm) of the
tire pressure warning system initiators.
The radio waves may affect the opera-
tion of such devices.
●Users of any electrical medical device
other than implantable cardiac pace-
makers, cardiac resynchronization
therapy-pacemakers or implantable
cardioverter defibrillators should con-
sult the manufacturer of the device for
information about its operation under
the influence of radio waves.Radio
waves could have unexpected effects
on the operation of such medical
devices.
Installing tire pressure warning
valves and transmitters
NOTICE
■Repairing or replac ing tires, wheels,
tire pressure warning valves, trans-
mitters 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 warn-
ing valves and transmitters 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 pressure
warning valves and transmitters
When a tire is repaired with liquid seal-
ants, the tire pressure warning valve and
transmitter may not operate properly. If a
liquid sealant is used , contact your Lexus
dealer or other qualified service shop as
soon as possible. After use of liquid seal-
ant, make sure to re place the tire pres-
sure warning valve and transmitter when
repairing or replacing the tire. ( P.259)

2606-3. Do-it-yourself maintenance
RC350AWD_RC350_RC300AWD_RC30
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■The tire pressure warning system
must be initialized in the following
circumstances:
 When rotating the tires.
 When the tire inflation pressure is
changed such as when changing
traveling speed.
 When changing the tire size.
When the tire pressure warning system
is initialized, the cu rrent tire inflation
pressure is set as the benchmark pres-
sure.
■How to initialize the tire pressure
warning system
1 Park the vehicle in a safe place and
turn the engine switch off.
Initialization cannot be performed while
the vehicle is moving.
2 Adjust the tire inflation pressure to
the specified cold tire inflation pres-
sure level.
Make sure to adjust th e tire pressure to the
specified cold tire infl ation pressure level.
The tire pressure warning system will oper-
ate based on this pressure level.
3 Turn the engine switch to IGNI-
TION ON mode.
4 Press and hold the tire pressure
warning reset switch until the tire pressure warning light blinks slowly
3 times.
5 Wait for a few minutes with the
engine switch in IGNITION ON
mode and then turn the engine
switch off.
■Initialization procedure
●Make sure to carry out initialization after
adjusting the tire inflation pressure.
Also, make sure the tires are cold before
carrying out initialization or tire inflation
pressure adjustment.
●If you have accidentally turned the engine
switch off during initialization, it is not
necessary to press the reset switch again
as initialization will restart automatically
when the engine switch has been turned
to IGNITION ON mode for the next
time.
●If you accidentally press the reset switch
when initialization is not necessary, adjust
the tire inflation pressure to the specified
level when the tires are cold, and conduct
initialization again.
■When initialization of the tire pressure
warning system has failed
Initialization ca n be completed in a few min-
utes. However, in the following cases, the
settings have not been recorded and the
system will not operate properly. If repeated
attempts to record tire inflation pressure
settings are unsuccessf ul, have the vehicle
inspected by your Lexus dealer.
●When operating the tire pressure warn-
ing reset switch, the tire pressure warning
light does not blink 3 times.
Initializing the tire pressure
warning system

2616-3. Do-it-yourself maintenance
RC350AWD_RC350_RC300AWD_RC30
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6
Maintenance and care
●After carrying out the initialization proce-
dure, the tire pressure warning light
blinks for 1 minute then stays on after
driving for 20 minutes.
The tire pressure warning valve and
transmitter is equipped with a unique
ID code. When replacing a tire pres-
sure warning valve and transmitter, it is
necessary to register the ID code.
Have the ID code registered by your
Lexus dealer. The recommended cold tire inflation
pressure and tire size are displayed on
the tire and loading information label.
(
P.322)
Tire valve
Tire pressure gauge
WARNING
■When initializing the tire pressure
warning system
Do not operate the ti re pressure warning
reset switch 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.
Registering ID codes
Tire inflation pressure
Checking the specified tire infla-
tion pressure
Inspection and adjustment pro-
cedure
A
B

2686-3. Do-it-yourself maintenance
RC350AWD_RC350_RC300AWD_RC30
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Type BNormal fuse
Blown fuse
Type C
Normal fuse
Blown fuse
Type DNormal fuse
Blown fuse
■After a fuse is replaced
●If the lights do not turn on even after the fuse has been replaced, a bulb may need
replacement.
●If the replaced fuse blows again, have the
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 connected to cir-
cuits designed to prevent overload,
non-genuine parts or parts not designed for
this vehicle may be unusable.
A
B
A
B
A
B
WARNING
■To prevent system breakdowns and
vehicle fire
Observe the following precautions.
Failure to do so may cause damage to
the 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.
NOTICE
■Before replacing fuses
Have the cause of electrical overload
determined and repaired by your Lexus
dealer as soon as possible.

2726-3. Do-it-yourself maintenance
RC350AWD_RC350_RC300AWD_RC30
0_OM_(U)_1810there is no light leaking from the bulb base.
8Align the tabs and push the light
unit toward the front of the vehicle
to install it.
9
Install the 2 screws and cover.
1
0Remove the protective tape.
WARNING
■Replacing light bulbs
●Turn off the lights. Do not attempt to
replace 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 bulb with bare hands. When it is
unavoidable 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 scratched 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 the lig ht 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.

273
RC350AWD_RC350_RC300AWD_RC30
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7
7
When trouble arises
When trouble arises
.7-1. Essential informationEmergency flashers.................. 274
If your vehicle has to be stopped in an emergency .......................... 274
If the vehicle is trapped in rising water............................................ 275
7-2. Steps to take in an emergency If your vehicle needs to be towed.277
If you think something is wrong ........................................................ 280
Fuel pump shut off system ...... 281
If a warning light turns on or a warning buzzer sounds ....... 282
If a warning message is displayed 290
If you have a flat tire.................. 294
If the engine wi ll not start ........301
If you lose your keys ................. 303
If the fuel filler door cannot be opened........................................ 303
If the electronic key does not operate properly .................... 304
If the vehicle battery is discharged 306
If your vehicle overheats ........ 309
If the vehicle becomes stuck ......................................................... 313

2827-2. Steps to take in an emergency
RC350AWD_RC350_RC300AWD_RC30
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■Brake system warning light
■High coolant temperature warning light* (warning buzzer)
*: This light illuminates on the multi-information display.
■Charging system warning light*
*: Except F SPORT models: This light illuminates on the multi-information display.
F SPORT models: This light illuminates on the meter.
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, bu t then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspected by your Lexus dealer.
Actions to the warning lights or warning buzzers
Warning lightDetails/Actions
(U.S.A.)
or
(Canada)
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.
Warning lightDetails/Actions
Indicates that the engine coolant temperature is too high
 Immediately stop the vehicle in a safe place.
Handling method ( P.309)
Warning lightDetails/Actions
Indicates a malfunction in the vehicle’s charging system
 Immediately stop the vehicle in a safe place and contact your Lexus
dealer.