2020 LEXUS RX350 key battery

3696-3. Do-it-yourself maintenance
6
Maintenance and care
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
precautions 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 pro-
cedure below to initialize the system.
1 Shift the shift lever to P.
2 Open and close any of the doors.
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 lo ck/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 reconnected,
the vehicle will return the engine switch
mode to the status it was in before the
battery was disconnected. Make sure to
turn off the power before disconnect the
battery. Take extra care when connecting
the battery if the engine switch mode
prior to discharge is unknown.
If the system will not start even after multiple
attempts at all the methods above, 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

3896-3. Do-it-yourself maintenance
6
Maintenance and care
■Replacing the rear wiper insert
Have the rear wiper inse rt replaced by your
Lexus dealer.
■Handling of the windshield wiper blades
and inserts
Improper handling of the windshield wiper
blades and inserts may cause them to be
damaged. If it is difficult to follow the wiper
blade and insert replacement procedure
precisely, contact your Lexus dealer.
■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 operationa l range will be reduced.
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
the local laws.
1Take out the mechanical key.
2 Remove the cover.
To prevent damage to the key, cover the tip
Electronic key battery
Replace the battery with a new one
if it is depleted.
You will need the following items:
Replacing the battery

3906-3. Do-it-yourself maintenance
of the flathead screwdriver with a tape.
3Remove the depleted battery.
When removing the cover, the electronic
key module may stick to the cover and the
battery may not be visible. In this case,
remove the electronic key module in order
to remove the battery.
Insert a new battery with the “+” terminal
facing up.
WARNING
■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.

403
7
7
When trouble arises
When trouble arises
.7-1. Essential informationEmergency flashers.................. 404
If your vehicle has to be stopped in an emergency .......................... 404
If the vehicle is trapped in rising water............................................ 405
7-2. Steps to take in an emergency If your vehicle needs to be towed........................................................ 407
If you think something is wrong .......................................................... 411
Fuel pump shut off system ...... 412
If a warning light turns on or a warning buzzer sounds ........ 413
If a warning message is displayed ........................................................ 422
If you have a flat tire.................. 426
If the engine wi ll not start .......438
If you lose your keys ................. 440
If the fuel filler door cannot be opened........................................ 440
If the electronic key does not operate properly ..................... 441
If the vehicle battery is discharged ........................................................ 443
If your vehicle overheats ........ 447
If the vehicle becomes stuck ........................................................ 449

4397-2. Steps to take in an emergency
7
When trouble arises
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.439)
One of the following may be the cause
of the problem:
 One or both of the battery terminals
may be disconnected. ( P.369)
 The battery may be discharged.
( P.443)
 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.
Do not use this starting procedure
except in cases of emergency.
1 Turn the engine switch to IGNI-
TION ON mode and check that the parking brake is set. (
P.179,
185)
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.
Starting the engine in an emer-
gency

4417-2. Steps to take in an emergency
7
When trouble arises
the lever to open the fuel filler door.
When using a screwdriver, make sure to
wrap its tip with tape to protect the cover.
■When the electronic key does not work
properly
●Make sure that the smart access system
with push-button star t has not been dis-
abled at your Lexus dealer. If it has been
disabled, re-enable it.
●Check if battery-saving mo de is set. If it is
set, cancel the function. ( P.114)
■Unlocking the door
Use the mechanical key ( P.95) in
order to perform th e following opera-
tions:
If the electronic key does not
operate properly
If communication between the
electronic key and vehicle is inter-
rupted ( P.114) 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 can be opened and the
engine can be started by following
the procedure below.
NOTICE
■In case of a smart access system with
push-button start malfunction or
other key-rela ted problems
Take your vehicle with all the electronic
keys provided with your vehicle to your
Lexus dealer.
Locking and unlocking the doors

4437-2. Steps to take in an emergency
7
When trouble arises
When the smart access system with
push-button start is deactivated in custom-
ization setting, the engine switch will turn
to ACCESSORY mode.
3 Firmly depress the brake pedal and
check that is shown on the
multi-information display.
4 Press the engine switch shortly and
firmly.
In the event that the engine still cannot
be started, contact your Lexus dealer.
■Stopping the engine
Shift the shift lever to P, set the parking
brake, and press the engine switch as you
normally do when stopping the engine.
■Replacing the 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.389)
■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.179)
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.

4447-2. Steps to take in an emergency
If you have a set of jumper (or booster)
cables and a second vehicle with a bat-
tery, you can jump start your vehicle by
following the steps below.
1Confirm 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.68)
2 Open the hood. ( P.363)
3 Connect a positive jumper cable clamp to on your vehicle and connect the
clamp on the other end of the positive cab le to on the second vehicle. Then,
connect a negative cable clamp to on the second vehicle and connect the
clamp at the other end of the negative cable to .
Positive (+) battery terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic poin t away from the battery and any mov-
ing parts as shown in the illustration
4 Start the engine of the second vehi-
cle. Increase the engine speed
slightly and maintain at that level for
approximately 5 minutes to recharge the battery of your vehi-
cle.
5 Open and close any of the doors of
your vehicle with the engine switch
off.
Restarting the engine
A
B
C
D
A
B
C
D