2019 LEXUS RC300 key battery

2536-3. Do-it-yourself maintenance
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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

2656-3. Do-it-yourself maintenance
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Maintenance and care
When an air conditioning odor comes out
continuously, replace the air conditioning
filter.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-but-
ton start and wireless remote control will
not function properly.
●The operational range will be reduced.
■When the card key battery needs to be
replaced (if equipped)
The battery for the card key is available only
at Lexus dealers. Your Lexus dealer can
replace the battery for you.
 Flathead screwdriver
 Small flathead screwdriver
 Lithium battery CR2032
■Use a CR2032 lithium battery
●Batteries can be purchased at your Lexus
dealer, local electrical appliance shops or
camera stores.
●Replace only with the same or equivalent
type recommended by the manufacturer.
●Dispose of used batteries according to
local laws.
NOTICE
■When using the air conditioning sys-
tem
Make sure that a filter is always installed.
Using the air conditioning system without
a filter may cause damage to the system.
Electronic key battery
Replace the battery with a new one
if it is depleted.
As the key may be damaged if the
following procedure is not per-
formed properly, it is recom-
mended that key battery
replacement be performed by your
Lexus dealer.
Items to prepare

2666-3. Do-it-yourself maintenance
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1Take out the mechanical key.
2
Remove the cover.
To prevent damage to the key, wrap the tip
of the screwdriver with tape.
3Remove the depleted battery.
Insert a new battery with the “+” terminal
facing up.
Replacing the batteryWARNING
■Removed battery and other parts
These parts are small and if swallowed by
a child, they can cause choking. Keep
away from children. Failure to do so
could result in death or serious injury.
NOTICE
■For normal operation after replacing
the battery
Observe the following precautions to
prevent accidents:
●Always work with dry hands.Moisture
may cause the battery to rust.
●Do not touch or move any other com-
ponent inside the remote control.
●Do not bend either of the battery ter-
minals.

273
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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

2937-2. Steps to take in an emergency
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When trouble arises
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.
■If “Oil Maintenance Required Soon” is
displayed
Indicates that the engine oil is scheduled to
be changed. (The indicator will not work
properly unless the oil maintenance data
has been reset.)
Check the engine oil, and change if neces-
sary. After changing the engine oil, the oil
change system shou ld be reset. (P.250)
■If “Oil Maintenance Required” is dis-
played
Indicates that the engine oil should be
changed. (After the engine oil is changed
and the oil maintenance data has been
reset.)
Check and change the en gine oil, and oil fil-
ter by your Lexus deal er. After changing the
engine oil, the oil change system should be
reset. ( P.250)
■If a message that indicates the need for
visiting your Lexus dealer is displayed
The system or part shown on the
multi-information display is malfunctioning.
Have the vehicle inspected by your Lexus
dealer immediately.
■If “See Owner’s Manual” is displayed
●If the following messages are shown, fol-
lowing the instructions, accordingly.
• “Engine Coolant Temp High” ( P.309)
●If any of the following messages are
shown on the multi-information display, it
may indicate a malfunction. Have the
vehicle inspected by your Lexus dealer
immediately.
• “Braking Power Low”
• “Access System with Elec. Key Malfunc- tion”
●If any of the following messages are
shown on the multi-information display, it
may indicate a malfunction. Immediately
stop the vehicle and contact your Lexus
dealer.
• “Oil Pressure Low”
• “Charging System Malfunction” NOTICE
■“High Power Consumption Partial
Limit On AC/Heater Operation” is
frequently shown
There is a possible malfunction relating
to the charging system or the battery
may be deteriorating. Have the vehicle
inspected by your Lexus dealer.

3027-2. Steps to take in an emergency
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The engine starting system may be
malfunctioning due to an electrical
problem such as electronic key battery
depletion or a blown fuse. However, an
interim measure is available to start the
engine. (P.302)
One of the following may be the cause
of the problem:
 One or both of the battery terminals
may be disconnected. ( P.253)
 The battery may be discharged.
( P.306)
 There may be a malfunction in the
steering lock system.
Contact your Lexus dealer if the problem
cannot be repaired, or if repair procedures
are unknown.
When the engine does not start, the
following steps can be used as an
interim measure to start the engine if
the engine switch is functioning nor-
mally:
1 Set the parking brake.
2 Shift the shift lever to P.
3 Turn the engine switch to ACCES-
SORY mode. 4
Press and hold the engine switch
for about 15 seconds while
depressing the brake pedal firmly.
Even if the engine can be started using
the above steps, the system may be
malfunctioning. Have the vehicle
inspected by your Lexus dealer.
The starter motor does not turn
over
The starter motor does not turn
over, the interior lights and head-
lights do not turn on, or the horn
does not sound.
Emergency start function

3047-2. Steps to take in an emergency
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■When the electronic key does not work
properly
●Make sure that the smart access system
with push-button start has not been deac-
tivated in the customization setting. If it is
off, turn the function on.
●Check if battery-saving mode is set. If it is
set, cancel the function. ( P.94)
■Unlocking the door
Use the mechanical key ( P.82) in
order to perform the following opera-
tions: 1
Insert the mechanical key while
pulling on the driver’s door handle.
2
Unlocking the door.
3
Remove the key, return the handle,
and then pull the handle again.
■Locking the door
1
Move the inside lock button to the
lock position.
2
Close the door.
■Opening the trunk
Turn the mechanical key clockwise to
open. ( P.58)
If the electronic key does not
o
perate properly
If communication between the
electronic key and vehicle is inter-
rupted ( P.94) or the electronic
key cannot be used because the
battery is depleted, the smart
access system with push-button
start and wireless remote control
cannot be used. In such cases, the
doors and trunk can be opened and
the engine can be started by follow-
ing the procedure below.
NOTICE
■In case of a smart access system with
push-button start malfunction or
other key-related problems
Take your vehicle with all the electronic
keys provided with your vehicle, includ-
ing the card key, to your Lexus dealer.
Locking and unlocking the doors
and opening the trunk

3067-2. Steps to take in an emergency
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■Stopping the engine
Shift the shift lever to P and press the engine
switch as you normally do when stopping
the engine.
■Electronic key battery
As the above procedure is a temporary
measure, it is recomme nded that the elec-
tronic key battery be replaced immediately
when the battery is depleted. ( P.265)
■Changing engine switch modes
Release the brake pedal and press the
engine switch in step 3 above.
The engine does not start and modes will be
changed each time the switch is pressed.
(  P.126)
If you have a set of jumper (or booster)
cables and a second vehicle with a
12-volt battery, you can jump start your
vehicle by following the steps below.
1 Confirm that the electronic key is
being carried.
When connecting the jumper (or booster)
cables, depending on the situation, the
alarm may activate and doors locked.
( P.59)
2 Open the hood. ( P.245)
If the vehicle battery is dis-
charged
The following procedures may be
used to start the engine if the vehi-
cle’s battery is discharged.
You can also call your Lexus dealer
or a qualified repair shop.
Restarting the engine