battery LEXUS RCF 2021 Service Manual

2846-4. Do-it-yourself maintenance
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 battery
WARNING
■Battery precautions
Observe the following precautions.
Failure to do so may result in death or
serious injury.
●Do not swallow the battery. Doing so
may cause chemical burns.
●A coin battery or button battery is
used in the electronic key. If a battery is
swallowed, it may cause severe chemi-
cal burns in as little as 2 hours and may
result in death or serious injury.
●Keep away new and removed batteries
from children.
●If the cover cannot be firmly closed,
stop using the electronic key and stow
the key in the place where children
cannot reach, and then contact your
Lexus dealer.
●If you accidentally swallow a battery or
put a battery into a part of your body,
get emergency medical attention
immediately.
■To prevent battery explosion or leak-
age of flammable liquid or gas
●Replace the battery with a new battery
of the same type. If a wrong type of
battery is used, it may explode.
●Do not expose batteries to extremely
low pressure due to high altitude or
extremely high temperatures.
●Do not burn, break or cut a battery.
NOTICE
■When replacing the battery
Use a flathead screwdriver of appropri-
ate size. Applying excessive force may
deform or damage the cover.
■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.

2856-4. Do-it-yourself maintenance
6
Maintenance and care
1Turn the engine switch off.
2 Open the fuse box cover.
Engine compartment: type A fuse
box
Push the tab in and lift the lid off.
Engine compartment: type B fuse
box
Push the tab in and lift the lid off.
Driver’s side instrument panel
Remove the lid.
NOTICE
●Do not bend either of the battery ter-
minals.
Checking and replacing
fuses
If any of the electrical components
do not operate, a fuse may have
blown. If this happens, check and
replace the fuses as necessary.
Checking and replacing fuses

293
7
7
When trouble arises
When trouble arises
.7-1. Essential informationEmergency flashers.................. 294
If your vehicle has to be stopped in an emergency .......................... 294
If the vehicle is trapped in rising water............................................ 295
7-2. Steps to take in an emergency If your vehicle needs to be towed........................................................ 297
If you think something is wrong ........................................................ 300
Fuel pump shut off system ...... 301
If a warning light turns on or a warning buzzer sounds ....... 302
If a warning message is displayed ......................................................... 310
If you have a flat tire (vehicles with a spare tire) ................................ 313
If you have a flat tire (vehicles with an emergency tire puncture
repair kit) .................................... 319
If the engine wi ll not start .......329
If you lose your keys .................. 331
If the fuel filler door cannot be opened......................................... 331
If the electronic key does not operate properly .................... 332
If the vehicle battery is discharged ........................................................ 334
If your vehicle overheats ........ 337
If the vehicle becomes stuck ........................................................ 339

2947-1. Essential information
7-1.Essential information
Press the switch to flash all of the turn
signal lights.
To turn them off, press the switch once
again.
■Emergency flashers
If the emergency flashers are used for a
long time while the engine is not operating,
the battery may discharge.
1 Steadily step on the brake pedal
with both feet and firmly depress it.
Do not pump the brake pedal repeatedly
as this will increase the effort required to
slow the vehicle.
2Shift the shift lever to N.
If the shift lever is shifted to N
3 After slowing down, stop the vehi-
cle in a safe place by the road.
4 Stop the engine.
If the shift lever cannot be shifted to
N
3 Keep depressing the brake pedal
with both feet to reduce vehicle
speed as much as possible.
4 To stop the engine, press and hold
the engine switch for 2 consecutive
Emergency flashers
The emergency flashers are used to
warn other drivers when the vehicle
has to be stopped on the road due
to a breakdown, etc.
Operating instructions
If your vehicle has to be
stopped in an emergency
Only in an emergency, such as if it
becomes impossible to stop the
vehicle in the normal way, stop the
vehicle using the following proce-
dure:
Stopping the vehicle

3087-2. Steps to take in an emergency
interconnecting wiring and power sources.
(  P.29)
■Front passenger detection sensor, seat
belt reminder and warning buzzer
●If luggage is placed on the front passen-
ger seat, the front passenger detection
sensor may cause th e warning light to
flash and the warning buzzer to sound
even if a passenger is not sitting in the
seat.
●If a cushion is placed on the seat, the sen-
sor may not detect a passenger, and the
warning light may not operate properly.
■If the malfunction indicator lamp comes
on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving
trips.
If the light does not go off even after several
trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning
light (warning buzzer)
When the battery charge becomes insuffi-
cient or the voltage temporarily drops, the
electric power steeri ng system warning
light may come on and the warning buzzer
may sound.
■When the tire pressure warning light
comes on
Check the tire inflation pressure and adjust
to the appropriate level. Pushing the tire
pressure warning reset switch will not turn
off the tire pressure warning light.
■The tire pressure warning light may
come on due to natural causes
The tire pressure wa rning light may come
on due to natural causes such as natural air
leaks and tire inflation pressure changes
caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the
warning light (after a few minutes).
■When a tire is replaced with a spare tire
The spare tire is not equipped with a tire
pressure warning valve and transmitter. If a
tire goes flat, the tire pressure warning light
will not turn off even though the flat tire has
been replaced with the spare tire.
■Conditions that the tire pressure warn-
ing system may not function properly
 P.276
■If the tire pressure warning light fre-
quently comes on after blinking for 1
minute
If the tire pressure wa rning light frequently
comes on after blinking for 1 minute when
the engine switch is turned to IGNITION
ON mode, have it checked by your Lexus
dealer.
WARNING
■If both the ABS and the brake system
warning lights remain on
Stop your vehicle in a safe place immedi-
ately and contact your Lexus dealer. The
vehicle will become extremely unstable
during braking, and the ABS system may
fail, which could cause an accident
resulting in death or serious injury.
■When the electric power steering
system warning light comes on
The steering wheel may become
extremely heavy.
When steering wheel operations are
heavier than usual, grip the steering
wheel firmly and operate it using more
force than usual.
■If the tire pressure warning light
comes on
Be sure to observe the following precau-
tions. Failure to do so could cause a loss
of vehicle control and result in death or
serious injury.
Vehicles with a spare tire
●Stop your vehicle in a safe place as
soon as possible. Adjust the tire infla-
tion pressure immediately.

3117-2. Steps to take in an emergency
7
When trouble arises
The warning lights and warning buzzers operate as follows depending on the con-
tent of the message. If a message indicates the need for inspection by a dealer, have
the vehicle inspected by your Lexus dealer immediately.
 In some situations, the master warning light and warning buzzer may not oper-
ate as specified. In this case, follow the instructions displayed in the warning
message.
 If a warning light comes on or flashes at the same time that a warning message is
displayed, take corrective actio n according to the warning light. ( P.302)
*: A buzzer sounds the first time a message is shown on the multi-information display.
■Warning messages
The warning messages explained below
may differ from the actual messages
according to operation conditions and vehi-
cle specifications.
■Warning buzzer
In some cases, the bu zzer may not be heard
due to being in a noisy location or audio
sound.
■If “Engine Oil Level Low Add or
Replace” is displayed
The engine oil level is low. Check the level
of the engine oil, and add if necessary. This message ma
y appear if the vehicle is
stopped on a slope. Move the vehicle to a
level surface and chec k to see if the mes-
sage disappears.
■If “Engine Stopped Steering Power
Low” is displayed
This message is displayed if the engine is
stopped while driving.
When steering wheel operations are
heavier than usual, gr ip the steering wheel
firmly and operate it using more force than
usual.
■If “Power Turned Off to Save Battery” is
displayed
Power was turned off due to the automatic
Messages and warnings
Warning buzzer*Warning
Comes onSounds
Indicates an important situat ion, such as when a sys-
tem related to driving is ma lfunctioning or that dan-
ger may result if the co rrection procedure is not
performed
FlashesSoundsIndicates a situation, such as when damage to the
vehicle or danger may result
Comes onDoes not sound
Indicates a condition, such as malfunction of electri-
cal components, their cond ition, or indicates the
need for maintenance
FlashesDoes not sound
Indicates a situation, such as when an operation has
been performed incorrectly, or indicates how to
perform an operation correctly

3127-2. Steps to take in an emergency
power off function. Next time when starting
the engine, increase the engine speed
slightly and maintain that level for approxi-
mately 5 minutes to recharge the battery.
■If “Headlight System Malfunction Visit
Your Dealer” is displayed
The following systems may be malfunction-
ing. Have the vehicle inspected by your
Lexus dealer immediately.
●The LED headlight system
●The automatic headlight leveling system
●Automatic High Beam
■If “Radar Cruise Control Unavailable” is
displayed
The dynamic radar cruise control system
cannot be used temporar ily. Use the system
when it becomes available again.
■If a message that indicates the malfunc-
tion of front camera is displayed
The following systems may be suspended
until the problem shown in the message is
resolved. ( P.155, 305)
●PCS (Pre-Collision System)
●LDA (Lane Departure Alert with steering
control)
●Dynamic radar cruise control
●Automatic High Beam
■If “Maintenance Required Soon” is dis-
played
Indicates that all maintenance according to
the driven distance on the maintenance
schedule
* should be performed soon.
Comes on approximately 4500 miles
(7200 km) after the message has been
reset. If necessary, perform maintenance.
Please reset the message after the mainte-
nance is performed. ( P.257)
*: Refer to the separa te “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.
■If “Maintenance Required Visit Your
Dealer” is displayed
Indicates that all maintenance is required to
correspond to the driven distance on the maintenance schedule
*.
Comes on approximately 5000 miles
(8000 km) after the message has been
reset. (The indicator will not work properly
unless the message ha s been reset.) Per-
form the necessary maintenance. Please
reset the message after the maintenance is
performed. ( P.257)
*: Refer to the separate “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the main tenance interval
applicable to your vehicle.
■If “Active Rear Wing Off Go to Settings
to turn On” is displayed
The active rear wing switch was pressed
when the active rear wing
* was disabled.
Enable the active rear wing before pressing
the active rear wing switch. ( P.195)
*: If equipped
■If “TVD System Overheated Reduce
Engine Speed and Load” is displayed
The TVD system
* has overheated, this mes-
sage may be displayed when driving under
high load conditions, such as the following:
●When driving at high speeds or through
sharp turns continuously
●When either rear tire has lost traction
and spun continuously
Drive the vehicle for a while, while avoiding
high load conditions.
*: If equipped
■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 instruct ions, accordingly.
• “Engine Coolant Temp High” ( P.337)
• “Transmission Fluid Temp High” ( P.132)
●If any of the following messages are
shown on the multi-information display, it
may indicate a malfunction. Have the

3137-2. Steps to take in an emergency
7
When trouble arises
vehicle inspected by your Lexus dealer
immediately.
• “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.
• “Braking Power Low”
• “Charging System Malfunction”
• “Oil Pressure Low”
 Stop the vehicle in a safe place on a
hard, flat surface.
 Set the parking brake.
 Shift the shift lever to P.
 Stop the engine.
 Turn on the emergency flashers.
( P.294)
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.
If you have a flat tire (vehi-
cles with a spare tire)
Your vehicle is equipped with a
spare tire. The flat tire can be
replaced with the spare tire.
For details about tires: P.273
WARNING
■If you have a flat tire
Do not continue driving with a flat tire.
Driving even a short distance with a flat
tire can damage the tire and the wheel
beyond repair, which could result in an
accident.
Before jacking up the vehicle

3297-2. Steps to take in an emergency
7
When trouble arises
One of the following may be the cause
of the problem:
There may not be sufficient fuel in
the vehicle’s tank.
Refuel the vehicle.
 The engine may be flooded.
Try to restart the engine again fol-
lowing correct starting procedures.
( P.128)
 There may be a malfunction in the
engine immobilizer system.
( P.57)
One of the following may be the cause
of the problem:
 The battery may be discharged.
( P.334)
 The battery terminal connections
may be loose or corroded.
( P.271)
NOTICE
●Store the emergency tire puncture
repair kit in the trunk. The kit may be
thrown around during sudden braking
and so forth, damaging the kit.
●Store the kit in its assigned place out of
reach of children.
●Do not disassemble or modify the kit.
Do not subject parts such as the air
pressure indicator to impacts. This may
cause a malfunction.
■To avoid damage to the tire pressure
warning valves and transmitters
When a tire is repaired with liquid seal-
ants, the tire pressu re warning valve and
transmitter may not operate properly. If a
liquid sealant is used , contact your Lexus
dealer as soon as possible. After use of
liquid sealant, make sure to replace the
tire pressure warnin g valve and transmit-
ter when repairing or replacing the tire.
(
P.277)
If the engine will not start
If the engine will not start even
though correct starting procedures
are being followed ( P.128), con-
sider each of the following points:
The engine will not start even
though the starter motor oper-
ates normally.
The starter motor turns over
slowly, the interior lights and
headlights are dim, or the horn
does not sound or sounds at a low
volume.

3307-2. Steps to take in an emergency
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.330)
One of the following may be the cause
of the problem:
 One or both of the battery terminals
may be disconnected. ( P.271)
 The battery may be discharged.
( P.334)
 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