2021 LEXUS ES300h key battery

3937-2. Steps to take in an emergency
7
When trouble arises
6Open and close any of the doors of
your vehicle with the power switch
off.
7 Maintain the engine speed of the
second vehicle and start the hybrid
system of your vehicle by turning
the power switch to ON mode.
8 Make sure the “READY” indicator
comes on. If the indicator does not
come on, contact your Lexus
dealer.
9 Once the vehicle’s hybrid system
has started, remove the jumper
cables in the exact reverse order
from which they were connected.
10 Close the exclusive jump starting
terminal cover, and reinstall the
fuse box cover to its original posi-
tion.
Once the hybrid system starts, have the
vehicle inspected at your Lexus dealer as
soon as possible.
■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 headlights and the audio sys-
tem while the hybrid system is stopped.
●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.
■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.
●Some systems may require initialization.
(  P.431)
■When removing the 12-volt battery ter-
minals
When the 12-volt battery terminals are
removed, the information stored in the
ECU is cleared. Before removing the 12-
volt battery terminals, contact your Lexus
dealer.
■Charging the 12-volt battery
The electricity stored in the 12-volt battery
will discharge gradually 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 recharging or replacing the 12-
volt battery
●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.
■When replacing the 12-volt battery
●Use a 12-volt battery that conforms to
European regulations.
●Use a 12-volt battery that the case size is
same as the previous one (LN2), 20 hour
rate capacity (20HR) is equivalent
(60Ah) or greater, and performance rat-
ing (CCA) is equivalent (345A) or
greater.

446What to do if... (Troubleshooting)
1-1.What to do if... (Troubleshooting)What to do if... (Troubleshooting)
If you lose your mechanical keys,
new genuine mechanical keys can
be made by your Lexus dealer.
( P.388)
 If you lose your electronic keys, the
risk of vehicle theft increases signifi-
cantly. Contact your Lexus dealer
immediately. ( P.388)
 Is the electronic key battery weak or
depleted? ( P.347)
 Is the power switch in ON mode?
When locking the doors, turn the power
switch off. ( P.148)
 Is the electronic key left inside the
vehicle?
When locking the doors, make sure that
you have the electronic key on your per-
son.
The function may not operate prop-
erly due to the condition of the radio
wave. ( P.114) 
Is the child-protector lock set?
The rear door cannot be opened
from inside the vehicle when the
lock is set.
Open the rear door from outside
and then unlock the child-protector
lock. ( P.104)
 The function to prevent the elec-
tronic key from being left inside the
trunk will operate and you can open
the trunk as usual. Take the key out
from the trunk. ( P.109)
 Did you press the power switch
while firmly depressing the brake
pedal? ( P.145)
 Is the shift lever in P? ( P.152)
 Is the electronic key anywhere
detectable inside the vehicle?
( P.112)
 Is the steering wheel unlocked?
( P.146)
 Is the electronic key battery weak or
depleted?
If you have a problem, check the
following before contacting your
Lexus dealer.
The doors cannot be locked,
unlocked, opened or closed
You lose your keys
The doors cannot be locked or
unlocked
The rear door cannot be opened
The trunk lid is closed with the
electronic key left inside
If you think something is wrong
The hybrid system does not start

Alphabetical index451
Distance until next engine oil change .... 80
Do-it-yourself maintenance ......................313
Door courtesy lights ....................................277
Door lockDoors.................................................................. 101
Smart access system with push-button start ....................................................................112
Wireless remote control........................... 99
Doors ................................................................... 101 Automatic door lock ing and unlocking
system ........................................................... 104
Door glasses ................................................. 130
Door lock.......................................................... 101
Open door warning buzzer ....... 102, 104
Outside rear view mirrors ...................... 127
Rear door child-protectors ................... 104
Drive distance .................................................. 82
Drive info 1/Drive info 2 .............................. 82
Driver’s seat position memory .................120 Driving position memory.........................120
Memory recall function ............................ 122
Drive-start control ........................................ 137
Driving................................................................136 Break-in tips ................................................... 137
Correct driving posture .............................23
Driving Mode Select switch................... 213
Hybrid vehicle driving tips .................... 252
Procedures .....................................................136
Winter drive tips......................................... 254
Driving information display ........................ 82
Driving Mode Select switch......................213
Driving range ................................................... 82
Driving support system information display ............................................................................. 83
Dynamic radar cruise control with full- speed range................................................. 198Warning message.....................................206
E
ECB (Electronically Controlled Brake Sys- tem) ................................................................ 248
Eco drive mode ..............................................213 EDR (Event data recorder) ............................7
Elapsed time ..................................................... 82
Electric motor (traction motor) .................. 61
Electric Power Steering (EPS)
Function ..........................................................248
Warning light ............................................... 367
Electronically Controlled Brake System (ECB) ............................................................ 248
Electronic key .................................................. 98 Battery-saving function.............................. 113
If the electronic key does not operate properly ...................................................... 389
Replacing the battery ............................... 347
Emergency, in case of If a warning buzzer sounds.................. 365
If a warning light turns on...................... 365
If a warning message is displayed .....375
If the 12-volt battery is discharged ..... 391
If the electronic key does not operate properly ...................................................... 389
If the fuel filler do or cannot be opened
......................................................................... 388
If the hybrid system will not start ....... 386
If the vehicle is trapped in rising water ......................................................................... 359
If you have a flat tire .................................. 379
If you lose your keys ................................ 388
If you think something is wrong..........364
If your vehicle becomes stuck ............ 399
If your vehicle has to be stopped in an emergency ................................................ 358
If your vehicle needs to be towed ...... 361
If your vehicle overheats ....................... 396
Emergency flashers ....................................358
Energy monitor ............................................... 90
Engine ACCESSORY mode............................... 148
Compartment................................................321
Hood ................................................................. 319
How to start the hybrid system............ 145
Identification number .............................. 403
If the hybrid system will not start ....... 386

454Alphabetical index
J
JackPositioning a floor jack..............................319
Vehicle-equipped jack .......................... 380
Jack handle ....................................................380
Jam protection function Moon roof .......................................................133
Power trunk opener and closer .......... 109
Power windows........................................... 130
K
Keyless entrySmart access system with push-button start ....................................................................112
Wireless remote control........................... 99
Keys...................................................................... 98 Battery-saving function ............................. 113
Electronic key ................................................. 98
If the electronic key does not operate properly.......................................................389
If you lose your keys................................ 388
Key number plate ......................................... 98
Keyless entry ................................ 101, 107, 112
Mechanical key.............................................. 98
Power switch .................................................145
Replacing the battery............................... 347
Warning buzzer .............................................112
Wireless remote control........................... 99
Knee airbags .................................................... 28
L
Lane Tracing Assist (LTA) .........................187 Operation........................................................187
Warning messages ................................... 195
Language (multi-information display) ... 84
LATCH anchors ............................................. 50
Lever Auxiliary catch lever ...................................319
Hood lock release lever...........................319
Internal trunk release lever .................... 109 Shift lever ......................................................... 152
Turn signal lever .......................................... 156
Wiper lever .....................................................167
Lexus climate concierge .......................... 263
Lexus Enform Safety Connect.................. 55
Lexus Safety System + 2.0 ........................ 174 Automatic High Beam ............................. 164
Dynamic radar cruise control with full-
speed range ............................................... 198
LTA (Lane Tracing Assist) ..................... 187
PCS (Pre-Collision System) ................. 180
RSA (Road Sign Assist)........................... 196
License plate lights......................................... 161 Light switch ...................................................... 161
Replacing light bulbs ................................352
Light bulbs Replacing .......................................................352
Wattage ......................................................... 408
Lights Automatic High Beam system ............. 164
Front interior lights .................................... 278
Front personal lights.................................278
Headlight switch............................................ 161
Interior lights list .......................................... 277
Interior lights ................................................. 277
Rear interior lights .....................................278
Rear personal lights .................................. 278
Trunk light ....................................................... 109
Turn signal lever .......................................... 156
Vanity lights ..................................................284
Wattage ......................................................... 408
Welcome light illumination control ....162
Lock steering column ..................................146
Low profile tire.............................................. 329
LTA (Lane Tracing Assist) .........................187 Operation ....................................................... 187
Warning messages.................................... 195
Luggage mat ................................................. 283
M
Maintenance Do-it-yourself maintenance ...................317

Alphabetical index457
........................................................................ 388
Opening the fuel tank cap ...................... 172
Regenerative braking ................................... 62
Remote Touch .............................................. 258
Replacing Electronic key battery.............................. 347
Fuses ................................................................ 349
Light bulbs..................................................... 352
Tires .................................................................. 379
Resetting the message indicating mainte- nance is required ........................................312
Road Sign Assist ............................................196
RSA (Road Sign Assist) ..............................196
S
SCB (Secondary Collision Brake) ....... 248
Seat belt reminder ligh t............................. 368
Seat belts............................................................ 24 Adjusting the seat belt................................ 26
Automatic Locking Retractor ................ 26
Child restraint system installation ......... 44
Cleaning and maintaining the seat belt.........................................................................309
Emergency Locking Retractor .............. 26
How to wear your seat belt ..................... 25
How your child should wear the seat belt ............................................................................ 25
Pregnant women, proper seat belt use .............................................................................24
Reminder light and buzzer ...................368
Seat belt extender ........................................ 25
Seat belt pretensioners ...............................27
SRS warning light ......................................366
Seat heaters ................................................... 273
Seating capacity.............................................143
Seat position memory..................................120
Seats..................................................................... 119 Adjustment precautions ............................ 119
Adjustment....................................................... 119
Child seats/child restraint system instal-lation................................................................. 43
Cleaning.........................................................309 Driving position memory ........................ 120
Head restraints..............................................123
Power easy access system .................... 120
Properly sitting in the seat ........................ 23
Seat heaters .................................................. 273
Seat position memory .............................. 120
Seat ventilators ............................................ 273
Seat ventilators ............................................. 273
Secondary Collision Brake (SCB) ....... 248
Sensor Automatic headlight system .................... 161
Automatic High Beam system ............. 164
Inside rear view mirror .............................. 127
Intuitive parking assist ................................216
LTA (Lane Tracing Assist) ..................... 187
Parking Support Brake function (rear-crossing vehicles).....................................241
Parking Support Brake function (static objects) ........................................................236
Radar sensor ....................................... 174, 210
Rain-sensing windshield wipers .......... 169
RCTA............................................................... 223
Service plug ...................................................... 64
Service reminder message .......................312
S-FLOW mode .............................................. 271
Shift lever Hybrid transmission................................... 152
Shift lever light ...............................................277
Side airbags ...................................................... 28
Side marker lights........................................... 161 Light switch ...................................................... 161
Side mirrors ..................................................... 127 Adjustment ...................................................... 127
BSM (Blind Spot Monitor)................... 208
Folding.............................................................. 128
Linked mirror functi on when reversing
............................................................................129
Mirror position memory .......................... 120
RCTA function ............................................ 222
Side turn signal lights ...................................156 Replacing light bulbs ................................352
Turn signal lever .......................................... 156