2019 LEXUS UX250H key battery

3426-3. Do-it-yourself maintenance
The 12-volt battery is located in the left-
hand side of luggage compartment.
■Before recharging
When recharging, the 12-volt battery pro-
duces hydrogen gas which is flammable
and explosive. Therefore, observe the fol-
lowing precautions before recharging:
●If recharging with the 12-volt battery
installed on the vehicle, be sure to discon-
nect the ground cable.
●Make sure the power switch on the char-
ger is off when connecting and discon-
necting the charger cables to the 12-volt
battery.
■After recharging/reconnecting the 12-
volt battery
●The hybrid system may not start. Follow
the procedure below to initialize the sys-
tem.
1
Shift the shift lever to P.
2
Open and close any of the doors.
3
Restart the hybrid system.
●Unlocking the doors using the smart
access system with pu sh-button start may
not be possible immediately after recon-
necting the 12-volt battery. If this hap-
pens, use the wireless remote control or
the mechanical key to lock/unlock the
doors.
●Start the hybrid system with the power
switch in ACC. The hybrid system may
WARNING
■When adding washer fluid
Do not add washer fluid when the hybrid
system is hot or operating as washer fluid
contains alcohol and may catch fire if
spilled on the engine etc.
NOTICE
■Do not use any fluid other than
washer fluid
Do not use soapy water or engine anti-
freeze instead of washer fluid.
Doing so may cause streaking on the
vehicle’s painted surfaces, as well as
damaging the pump leading to problems
of the washer fluid not spraying.
■Diluting washer fluid
Dilute washer fluid with water as neces-
sary.
Refer to the freezing temperatures listed
on the label of the washer fluid bottle.
12-volt battery
Location

3686-3. 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.
■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.
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.
NOTICE
■When cleaning the air intake vent
When cleaning the air intake vent, make
sure to only use a vacuum to suck out
dust and clogs. If a compressed air blow
gun, etc. is used to blow out dust and
clogs, the dust or clogs may be pushed
into the air intake ve nt, which may affect
the performance of the hybrid battery
(traction battery) and cause a malfunc-
tion.
■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 damaged. 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 Traction
battery cooling parts See owner’s
manual” is shown on the multi-infor-
mation 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. If the
warning message is shown, clean the air
intake vent immediately.
Electronic key battery
Replace the battery with a new one
if it is depleted.
Items to prepare

3696-3. Do-it-yourself maintenance
6
Maintenance and care
1Take out the mechanical key.
2
Remove the cover.
To prevent damage to the key, cover the tip
of the flathead screwdriver with a tape.
3Remove the depleted battery using
the small flathead screwdriver.
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
■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.

377
7
7
When trouble arises
When trouble arises
7-1. Essential informationEmergency flashers.................. 378
If your vehicle has to be stopped in an emergency .......................... 378
If the vehicle is trapped in rising water............................................ 379
7-2. Steps to take in an emergency If your vehicle needs to be towed......................................................... 381
If you think something is wrong ........................................................ 385
If a warning light turns on or a warning buzzer sounds ....... 386
If a warning message is displayed ........................................................ 395
If you have a flat tire.................. 399
If the hybrid system will not start ........................................................ 400
If you lose your keys ................. 402
If the fuel filler door cannot be opened........................................ 402
If the electronic key does not operate properly .................... 403
If the 12-volt battery is discharged ........................................................ 405
If your vehicle overheats ......... 410
If the vehicle becomes stuck . 413

3987-2. Steps to take in an emergency
reset. If necessary, perform maintenance.
Please reset the message after the mainte-
nance is performed. (P.328)
*: 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.328)
*: 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.339)
■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.339)
■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.410)
• “Front Camera Unavailable” ( P.196)
• “Radar Cruise Control Unavailable” ( P.196)
●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”
●If “Low Auxiliary Battery See Owner’s
Manual” 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.405)
*: Displays for about 6 seconds
●If “Maintenance required for Traction bat-
tery cooling parts See owner’s manual” 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 and filter of the hybrid battery (traction battery) are dirty, per-

4007-2. Steps to take in an emergency
One of the following may be the cause
of the problem:
The electronic key may not be func-
tioning properly. ( P.403)
 There may not be sufficient fuel in
the vehicle’s tank.
Refuel the vehicle. ( P.190)
 There may be a malfunction in the
immobilizer system. ( P.69)
 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
NOTICE
■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.
■When driving over bumps
If a vehicle has a flat tire, the vehicle
height will be lower than usual. Ensure
that nothing strikes the bottom of the
vehicle.
■To avoid damaging 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. Make sure to replace
the tire pressure warning valve and trans-
mitter when replacing the tire. ( P.350)
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.162)
The interior lights and head-
lights are dim, or the horn does
not sound or sounds at a low vol-
ume.

4037-2. Steps to take in an emergency
7
When trouble arises
reduction in fuel tank pressure before
refueling. To prevent fuel from spilling
out, turn the cap slowly when removing
it. During refueling, fuel may spill out
from the filler opening due to air being
discharged from inside the fuel tank.
Therefore, fill the fuel tank carefully and
slowly.
■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.125)
■Unlocking the door
Use the mechanical key ( P.106) to
perform the following operations.
If the electronic key does not
o
perate properly
If communication between the
electronic key and vehicle is inter-
rupted ( P.125) 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 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, includ-
ing the card key, to your Lexus dealer.
Locking and unlocking the doors

4057-2. Steps to take in an emergency
7
When trouble arises
setting, the power switch will turn to ACC.
3Firmly depress the brake pedal and
check that is shown on the
multi-information display.
4 Press the power switch.
In the event that the hybrid system still can-
not 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 recomme nded that the elec-
tronic key battery be replaced immediately
when the battery is depleted. ( P.368)
■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.164)
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.72)
2 Open the hood ( P.335) and fuse
box cover.
If the 12-volt battery is dis-
charged
The following procedures may be
used to start the hybrid system if the
vehicle’s 12-volt battery is dis-
charged.
You can also call your Lexus dealer
or a qualified repair shop.
Restarting the hybrid system