2019 LEXUS UX250H change key battery

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

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.)

Alphabetical Index465
Head-up display ........................................... 93
Intuitive parking assist.............................. 232
LTA (Lane-Tracing Assist) .....................210
Multi-information display .......................... 87
RCTA .............................................................. 239
Warning messages ..................................395
Distance until next engine oil change .. 80, 86
Do-it-yourself maintenance .................... 333
Door lock Doors................................................................ 108
Smart access system with push-button start .................................................................. 124
Wireless remote control......................... 106
Doors Automatic door lock ing and unlocking
system ............................................................... 111
Back door..........................................................112
Door glasses ..................................................145
Door lock........................................................ 108
Open door warning bu zzer .......... 109, 111
Outside rear view mirrors ...................... 142
Rear door child-protectors ....................... 111
Side doors ...................................................... 108
Drive distance .................................................. 89
Drive info 1/Drive info 2 .............................. 89
Driver’s seat position memory .................133
Drive-start control ........................................152
Driving................................................................152 Break-in tips ...................................................153
Correct driving posture ............................ 25
Driving mode select switch .................. 255
Hybrid vehicle driving tips ...................... 261
Procedures .....................................................152
Winter drive tips......................................... 263
Driving information display ........................ 88
Driving position memory............................133 Memory recall function ............................135
Driving range ................................................... 89
Driving support system information display ............................................................................. 90
Dynamic radar cruise control with full- speed range..................................................216
Warning message .........................224, 395
E
ECB (Electronically Controlled Brake Sys-
tem) ................................................................ 256
Eco drive mode ............................................ 255
EDR (Event data recorder) ........................... 8
E-Four .............................................................. 257
Elapsed time ..................................................... 89
Electric motor Location ............................................................. 62
Electric Power Steering (EPS) Function .......................................................... 257
Warning light .............................................. 388
Electronically Controlled Brake System (ECB) ............................................................ 256
Electronic key ................................................ 104 Battery-saving function............................ 125
If the electronic key does not operate properly ...................................................... 403
Replacing the battery .............................. 368
Emergency, in case of If a warning buzzer sounds.................. 386
If a warning light turns on...................... 386
If a warning message is displayed .... 395
If the 12-volt battery is discharged ... 405
If the electronic key does not operate properly ...................................................... 403
If the fuel filler do or cannot be opened
..........................................................................402
If the hybrid system will not start ....... 400
If the vehicle is trapped in rising water .......................................................................... 379
If you have a flat tire ................................. 399
If you lose your keys .................................402
If you think something is wrong......... 385
If your vehicle becomes stuck ...............413
If your vehicle has to be stopped in an emergency .................................................378
If your vehicle needs to be towed ...... 381
If your vehicle overheats ......................... 410