LEXUS UX250H 2019 Owners Manual

4017-2. Steps to take in an emergency
7
When trouble arises
of the problem:
The 12-volt battery may be dis-
charged. ( P.405)
 The 12-volt battery terminal con-
nections may be loose or corroded.
( P.342)
One of the following may be the cause
of the problem:
 The 12-volt battery may be dis-
charged. ( P.405)
 One or both of the 12-volt battery
terminals may be disconnected.
( P.342)
Contact your Lexus dealer if the problem
cannot be repaired, or if repair procedures
are unknown.
When the hybrid system does not start,
the following steps can be used as an
interim measure to start the hybrid sys-
tem if the power switch is functioning
normally.
Do not use this starting procedure
except in cases of emergency.
1 Press the parking brake switch to
check that the parking brake is set.
(P.172)
Parking brake indicator will come on.
2 Shift the shift lever to P.
3 Turn the power switch to ACC. 4
Press and hold the power switch for
about 15 seconds while depressing
the brake pedal firmly.
Even if the hybrid system can be
started using the above steps, the sys-
tem may be malfunctioning. Have the
vehicle inspected by your Lexus dealer.
The interior lights and head-
lights do not turn on, or the horn
does not sound.
Starting the hybrid system in an
emergency

4027-2. Steps to take in an emergency
1Remove the cover inside the lug-
gage compartment by inserting a
screwdriver.
When removing the cover, to prevent dam-
age, cover the tip of the screwdriver with a
rag.
2Pull the lever.
Using the lever to open the fuel filler
door may not allow for an adequate
If you lose your keys
New genuine mechanical keys can
be made by your Lexus dealer using
another mechanical key and the
key number stamped on your key
number plate. Keep the plate in a
safe place such as your wallet, not in
the vehicle.
NOTICE
■When an electronic key is lost
If the electronic key remains lost, the risk
of vehicle theft increases significantly.
Visit your Lexus deal er immediately with
all remaining electronic keys and the
card key (if equipped) that were pro-
vided with your vehicle.
If the fuel filler door cannot
b
e opened
If the fuel filler door opener switch
cannot be operated, contact your
Lexus dealer to service the vehicle.
In case where refueling is urgently
necessary, the following procedure
can be used to open the fuel filler
door.
Opening the fuel filler door

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

4047-2. Steps to take in an emergency
1Insert the mechanical key while
pulling on the driver’s door handle.
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.
■Key linked functions
The opening and closing of the power win-
dows and moon roof can be linked to key
operation by a customized setting. 1
Closes the windows and moon roof
(turn and hold)
2
Opens the windows and moon roof
(turn and hold)
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.
When the smart access system with push-
button start is deactivated in customization
WARNING
■When using the mechanical key and
operating the power windows or
moon roof (if equipped)
Operate the power window or moon
roof after checking to make sure that
there is no possibility of any passenger
having any of their body parts caught in
the window or moon roof.
Also, do not allow children 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

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

4067-2. Steps to take in an emergency
Push the tab in and lift the lid off.
3Open the exclusive jump starting
terminal cover.
4 Remove the engine cover.

4077-2. Steps to take in an emergency
7
When trouble arises
5Connect 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 .
Exclusive jump starting terminal (your vehicle)
Positive (+) battery terminal (second vehicle)
Negative (-) battery terminal (second vehicle)
Solid, stationary, unpainted metallic point away from the exclusive jump starting
terminal and any mo ving parts as shown in the illustration
6 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 12-volt battery of your
vehicle.
7 Open and close any of the doors of
your vehicle with the power switch
OFF.
8 Maintain the engine speed of the
second vehicle and start the hybrid
system of your vehicle by turning
the power switch to ON.
9 Make sure the “READY” indicator
comes on. If the indicator light does not come on, contact your Lexus
dealer.
10 Once the hybrid system has
started, remove the jumper cables
in the exact reverse order from
which they were connected.
11 Close the exclusive jump starting
terminal cover, and reinstall the fuse
box cover to its original position.
Once the hybrid system starts, have
the vehicle inspected at your Lexus
dealer as soon as possible.A
B
C
D
A
B
C
D

4087-2. Steps to take in an emergency
■Starting the hybrid system when the 12-
volt battery is discharged
The hybrid system cannot be started by
push-starting.
■To prevent 12-volt battery discharge
●Turn off the headlight s, the air condition-
ing system, the audio system, etc. while
the hybrid system is off.
●Turn off any unnecessary electrical com-
ponents when the vehicle is running at a
low speed for an extended period, such
as in heavy traffic.
■Charging the 12-volt battery
The electricity stored in the 12-volt battery
will discharge gradua lly even when the
vehicle is not in use, due to natural dis-
charge and the draining effects of certain
electrical appliances. If the vehicle is left for
a long time, the 12-volt battery may dis-
charge, and the hybrid system may be
unable to start. (The 12-volt battery
recharges automatically while the hybrid
system is operating.)
■When the 12-volt battery is removed or
discharged
●Information stored in the ECU is cleared.
When the 12-volt battery is depleted,
have the vehicle inspected at your Lexus
dealer.
●In some cases, it may not be possible to
unlock the doors using the smart access
system with push-button start when the
12-volt battery is discharged. Use the
wireless remote control or the mechani-
cal key to lock or unlock the doors.
●The hybrid system may not start on the
first attempt after the 12-volt battery has
recharged but will start normally after the
second attempt. This is not a malfunction.
●The power switch mode is memorized by
the vehicle. When the 12-volt battery is
reconnected, the system will return to the
mode it was in before the 12-volt battery
was discharged. Before disconnecting
the 12-volt battery, turn the power switch
off.
If you are unsure what mode the power
switch was in before the 12-volt battery discharged, be especially careful when
reconnecting the 12-volt battery.
●The power back door must be initialized.
(
 P.119)
■When replacing the 12-volt battery
●Use a Central Degassing type 12-volt
battery (European Regulations).
●Use a 12-volt battery that the case size is
same as the previous one (LN1), 20 hour
rate capacity (20HR) is equivalent
(45Ah) or greater, and performance rat-
ing (CCA) is equivalent (286A) or
greater.
• If the sizes differ, the 12-volt battery can- not be properly secured.
• If an improper 12-volt battery is used, bat-
tery performance may decrease and the
hybrid system may not be able to restart.
• If the 20 hour rate capacity is low, even if
the time period where the vehicle is not
used is a short time, the 12-volt battery
may discharge and hybrid system may
not be able to start.
●Use a 12-volt battery with a handle. If a
12-volt battery without a handle is used,
removal is more difficult.
●After exchanging, firmly attach the fol-
lowing items to the exhaust hole of the 12-
volt battery.
• Confirm that the elbow is securely attached to the exhaust hose and exhaust
hole.
• Confirm that the exhaust hole plug is securely attached to the exhaust hole that
the elbow is not attached to.
• Use the elbow/exhaust hole plug included with the 12-volt battery
exchanged or the on e installed on the
battery prior to the exchange. (Depend-
ing on the 12-volt battery to be
exchanged, the exhaust hole may be
plugged.)

4097-2. Steps to take in an emergency
7
When trouble arises
Exhaust hole
Exhaust hole plug
Exhaust hose
Elbow
For details, consult your Lexus dealer.
WARNING
■When removing the 12-volt battery
terminals
Always remove the negative (-) terminal
first. If the positive (+) terminal contacts
any metal in the surrounding area when
the positive (+) terminal is removed, a
spark may occur, leadin g to a fire in addi-
tion to electrical shocks and death or
serious injury.
■Avoiding 12-volt battery fires or
explosions
Observe the following precautions to
prevent accidentally igniting the flamma-
ble gas that may be emitted from the 12-
volt battery:
●Make sure each jumper cable is con-
nected to the correct terminal and that
it is not unintentiona lly in contact with
any other than the intended terminal.
A
B
C
D
●Do not allow the other end of the
jumper cable connected to the “+” ter-
minal to come into contact with any
other parts or metal surfaces in the
area, such as brackets or unpainted
metal.
●Do not allow the + and - clamps of the
jumper cables to come into contact
with each other.
●Do not smoke, use matches, cigarette
lighters or allow open flame near the
12-volt battery.
■12-volt battery precautions
The 12-volt battery contains poisonous
and corrosive acidic electrolyte, while
related parts contain lead and lead com-
pounds. Observe the following precau-
tions when handling the 12-volt battery:
●When working with the 12-volt battery,
always wear safety glasses and take
care not to allow any battery fluids
(acid) to come into contact with skin,
clothing or the vehicle body.
●Do not lean over the 12-volt battery.
●In the event that battery fluid (acid)
comes into contact with the skin or
eyes, immediately wash the affected
area with water and seek medical
attention.
Place a wet sponge or cloth over the
affected area until medical attention
can be received.
●Always wash your hands after handling
the 12-volt battery and other battery-
related parts.
●Do not allow children near the 12-volt
battery.
■After recharging the 12-volt battery
Have the 12-volt battery inspected at
your Lexus dealer as soon as possible.
If the 12-volt battery is deteriorating, con-
tinued use may cause the 12-volt battery
to emit a malodorous gas, which may be
detrimental to the health of passengers.

4107-2. Steps to take in an emergency
If the engine coolant temperature
gauge enters the red zone or
“Engine Coolant Temp High Stop in
a Safe Place See Owner’s Manual”
is shown on the multi-information
display
1
Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the hybrid system.
2
If you see steam:
Carefully lift the hood after the
steam subsides.
If you do not see steam:
Carefully lift the hood.
3
After the hybrid system has cooled
down sufficiently, inspect the hoses
WARNING
■When replacing the 12-volt battery
●When the vent plug is close to the hold
down clamp, the battery fluid (acid)
may leak.
●For information regarding battery
replacement, contact your Lexus
dealer.
●After exchanging, securely attach the
elbow connected to the exhaust hose,
and exhaust hole plug to the exhaust
hole of the exchanged 12-volt battery.
If not properly installed, gases (hydro-
gen) may leak into the vehicle interior,
and there is the possible danger of the
gas igniting and exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when charging the 12-volt bat-
tery from another vehicle in an emer-
gency. It cannot be used to jump start
another vehicle.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The engine coolant temperature
gauge ( P.78, 82) enters the
red zone, or a loss of hybrid sys-
tem power is experienced. (For
example, the vehicle speed does
not increase.)
 “Engine Coolant Temp High Stop
in a Safe Place See Owner’s
Manual” or “Hybrid system over-
heated Output power reduced” is
shown on the multi-information
display.
 Steam comes out from under the
hood.
Correction procedures