2020 Lexus ES300h key battery

3466-3. Do-it-yourself maintenance
■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.
Prepare the following before replacing
the battery:
 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
the local laws.
1Take out the mechanical key.
NOTICE
■To prevent damage to the vehicle
●Do not allow water or foreign matter to
enter the air intake vent when the
cover is removed.
●Carefully handle the removed filter so
that it will not be damage.
If the filter is damaged, have it replaced
with a new filter by your Lexus dealer.
●Make sure to reinstall the filter and
cover to their original positions after
cleaning.
●Do not install anything to the air intake
vent other than the exclusive filter for
this vehicle or use the vehicle without
the filter installed.
■If “Maintenance Required for Trac-
tion Battery Cooling Parts See
Owner’s Manual” is displayed on the
multi-information display
If the vehicle is continuously driven with
the warning message (indicating that
charging/discharging of the hybrid bat-
tery (traction battery) may become lim-
ited) displayed, the hybrid battery
(traction battery) may malfunction.
Electronic key battery
Replace the battery with a new one
if it is depleted.
Items to prepare
Replacing the battery

3476-3. Do-it-yourself maintenance
6
Maintenance and care
2Remove 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.
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
■When replacing the battery
Use a screwdriver of appropriate 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.
●Do not bend either of the battery ter-
minals.

355
7
7
When trouble arises
When trouble arises
7-1. Essential informationEmergency flashers.................. 356
If your vehicle has to be stopped in an emergency .......................... 356
If the vehicle is trapped in rising water............................................ 357
7-2. Steps to take in an emergency If your vehicle needs to be towed........................................................ 359
If you think something is wrong ........................................................ 362
If a warning light turns on or a warning buzzer sounds ....... 364
If a warning message is displayed ........................................................ 374
If you have a flat tire.................. 378
If the hybrid system will not start ........................................................ 385
If you lose your keys ................. 387
If the fuel filler door cannot be opened........................................ 387
If the electronic key does not operate properly .................... 388
If the 12-volt battery is discharged ........................................................ 390
If your vehicle overheats ........ 395
If the vehicle becomes stuck 398

3777-2. Steps to take in an emergency
7
When trouble arises
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.312)
*: 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.312)
*: Refer to the separa te “Scheduled Main-
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 should be
scheduled to be changed.
Check the engine oil and change it if neces-
sary. After changing the engine oil, make
sure to reset the message. ( P.312)
■If “Oil Maintenance Required” is dis-
played
Indicates that the engine oil should be
changed.
Check and change the en gine oil, and oil fil-
ter by your Lexus deal er. After changing the
engine oil, make sure to reset the message.
(  P.323)
■If a message that in dicates 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 a message that indicates the need for
referring to Owner’
s Manual is dis-
played
●If any of the following messages are
shown on the multi-information display,
follow the instructions.
• “Engine Coolant Temp High” ( P.395)
●If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malf unction. Have the
vehicle inspected by your Lexus dealer
immediately.
• “Access System with Elec. Key Malfunc-
tion”
• “Hybrid system malfunction”
•“Check Engine”
• “Hybrid battery system malfunction”
• “Accelerator system malfunction”
●If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malfun ction. Immediately
stop the vehicle and contact your Lexus
dealer.
• “Braking Power Low”
• “Charging System Malfunction”
• “Oil Pressure Low”
• “Hybrid system stopped”
• “Engine stopped”
●If “Low Auxiliary Battery” is shown
• When the display goes off after several
seconds
*:
Maintain the hybrid system operation for
more than 15 minutes and charge the 12-
volt battery.
• When the display does not go off:
Start up the hybrid system using the proce-
dures for “If the 12-volt battery is dis-
charged” ( P.390).
*: Displays for about 6 seconds
●If “Maintenance required for Traction bat-
tery cooling parts” is shown, the filter may
be clogged, the air intake vent may be
blocked, or there may be a gap in the
duct. Therefore, perform the following
correction procedure.
• If the air intake vent s and filters of the
hybrid battery (traction battery) are dirty,

3857-2. Steps to take in an emergency
7
When trouble arises
One of the following may be the cause
of the problem:
The electronic key may not be func-
tioning properly. ( P.389)
 There may not be sufficient fuel in
the vehicle’s tank.
Refuel the vehicle. ( P.170)
 There may be a malfunction in the
immobilizer system. ( P.67)
 There may be a malfunction in the
steering lock system.
 The hybrid system may be malfunc-
tioning due to an electrical problem
such as electronic key battery
depletion or a blown fuse. However,
depending on the type of malfunc-
tion, an interim measure is available
to start the hybrid system.
One of the following may be the cause
WARNING
■Speed limit when using the compact
spare tire
Do not drive at speeds in excess of 50
mph (80 km/h) when a compact spare
tire is installed on the vehicle.
The compact spare tire is not designed
for driving at high speeds. Failure to
observe this precaution may lead to an
accident causing deat h or serious injury.
■After using the tools and jack
Before driving, make sure all the tools
and jack are securely in place in their
storage location to reduce the possibility
of personal injury during a collision or
sudden braking.
NOTICE
■Be careful when driving over bumps
with the compact spare tire installed
on the vehicle
The vehicle becomes lower when driving
with the compact spare tire compared to
when driving with standard tires. Be
careful when driving over uneven road
surfaces.
■Driving with tire chains and the com-
pact spare tire
Do not fit tire chains to the compact
spare tire.
Tire chains may damage the vehicle body
and adversely affect driving perfor-
mance.
■When replacing the tires
When removing or fitting the wheels,
tires or the tire pressure warning valve
and transmitter, contact your Lexus
dealer as the tire pr essure warning valve
and transmitter may be damaged if not
handled correctly.
If the hybrid system will not
s
tart
Reasons for the hybrid system not
starting vary depending on the situ-
ation. Check the following and per-
form the appropriate procedure:
The hybrid system will not start
even though the correct starting
procedure is being followed.
(  P.143)
The interior lights and head-
lights are dim, or the horn does
not sound or sounds at a low vol-
ume.

3887-2. Steps to take in an emergency
■When the electronic key does not work
properly
●Make sure that the smart access system
with push-button start has not been deac-
tivated using the Remote Touch or at your
Lexus dealer. If it is off, turn the function
on.
●Check if battery-saving mode is set. If it is
set, cancel the function. ( P.111)
Use the mechanical key ( P.98) in
order to perform the following opera-
tions:
■Unlocking the door
1
Pull the driver’s door handle and
insert the mechanical key.
2
Unlock the door.
3
Remove the key, return the handle,
and then pull the handle again.
■Locking the door
1
With the door open, push down the
inside lock button.
2
Close the door.
■Opening the trunk
Turn the mechanical key clockwise to
If the electronic key does not
o
perate properly
If communication between the
electronic key and vehicle is inter-
rupted ( P.112) 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 hybrid system can be started by
following 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 to your
Lexus dealer as soon as possible.
Locking and unlocking the
doors, opening the trunk and
using the key linked functions

3897-2. Steps to take in an emergency
7
When trouble arises
open.
■Key linked functions
1
Closes the windows and the moon roof
(turn and hold)
2
Opens the windows and the moon roof
(turn and hold)
These settings must be customized at your
Lexus dealer.
1Ensure that the shift lever is in P and
depress the brake pedal.
2
Touch the Lexus emblem side of the
electronic key to the power switch.
When the electronic key is detected, a
buzzer sounds and the power switch will
turn to ON mode.
When the smart access system with push-
button start is deactivated in customization
setting, the power switch will turn to
ACCESSORY mode.
3Firmly depress the brake pedal and
check that is shown on the
multi-information display.
4
Press the power switch shortly and
firmly.
In the event that the hybrid system still
cannot be started, contact your Lexus
dealer.
■Stopping the hybrid system
Set the parking brake, shift the shift lever to
P and press the power switch as you nor-
mally do when stopping the hybrid system.
■Electronic key battery
As the above procedure is a temporary
measure, it is recommended that the elec-
tronic key battery be replaced immediately
when the battery is depleted. (P.346)
WARNING
■When using the mechanical key and
operating the power windows or
moon roof
Operate the power window after check-
ing to make sure that there is no possibil-
ity of any passenger having any of their
body parts caught in the window or
moon roof.
Also, do not allow ch ildren to operate the
mechanical key. It is possible for children
and other passengers to get caught in
the power window or moon roof.
Starting the hybrid system

3907-2. Steps to take in an emergency
■Changing power switch modes
Release the brake pedal and press the
power switch in step 3 above.
The hybrid system does not start and modes
will be changed each time the switch is
pressed. ( P.146)
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 using the following procedure.
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.70)
2 Open the hood ( P.319) and
open the fuse box cover.
If the 12-volt battery is dis-
charged
The following procedures may be
used to start the hybrid system if the
12-volt battery is discharged.
You can also call your Lexus dealer
or a qualified repair shop.
Restarting the hybrid system