
5268-2. Steps to take in an emergency
IS250_EE(OM53C51E)
■Stopping the engine
Shift the shift lever to P and press the engine switch as you normally do when stopping
the engine.
■Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the electronic
key battery be replaced immediately when the battery is depleted. (→P. 4 4 2 )
■Alarm (if equipped)
Using the mechanical key to lock the doors will not set the alarm system.
If a door is unlocked using the mechanical key when the alarm system is set, the alarm
may be triggered.
■Changing engine switch modes
Release the brake pedal and press the engine switch in step above.
The engine does not start and modes will be changed each time the switch is pressed.
(→P. 1 9 3 )
■When the electronic key does not work properly
●Make sure that the smart entry & start system has not been deactivated in the customi-
zation setting. If it is off, turn the function on.
(Customizable features →P. 551)
●Check if battery-saving mode is set. If it is set, cancel the function. (→P. 131)
CAUTION
■When using the mechanical key and operating the power windows and moon roof
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 power window and moon roof.
3

5298-2. Steps to take in an emergency
8
When trouble arises
IS250_EE(OM53C51E)
Start the engine of the second vehicle. Increase the engine speed slightly and
maintain at that level for approximately 5 minutes to recharge the battery of
your vehicle.
Open and close any of the doors of your vehicle with the engine switch off.
Maintain the engine speed of the second vehicle and start the engine of your
vehicle by turning the engine switch to IGNITION ON mode.
Once the vehicle’s engine has started, remove the jumper cables in the exact
reverse order from which they were connected.
Once the engine starts, have the vehicle inspected at any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional as soon
as possible.
■Starting the engine when the battery is discharged
The engine cannot be started by push-starting.
■To prevent battery discharge
●Turn off the headlights and the audio system while the engine is off.
●Turn off any unnecessary electrical components when the vehicle is running at a low
speed for an extended period, such as in heavy traffic.
■Charging the battery
The electricity stored in the battery will discharge gradually even when the vehicle is not
in use, due to natural discharge and the draining effects of certain electrical appliances. If
the vehicle is left for a long time, the battery may discharge, and the engine may be
unable to start. (The battery recharges automatically during driving.)
■When recharging or replacing the battery
●For vehicles with an alarm: Make sure that the key is not inside the vehicle when
recharging or replacing the battery. The key may be locked in the vehicle if the alarm is
activated. (→P. 8 5 )
●In some cases, it may not be possible to unlock the doors using the smart entry & start
system when the battery is discharged. Use the wireless remote control or the mechan-
ical key to lock or unlock the doors.
●The engine may not start on the first attempt after the battery has recharged but will
start normally after the second attempt. This is not a malfunction.
●The engine switch mode is memorized by the vehicle. When the battery is recon-
nected, the system will return to the mode it was in before the battery was discharged.
Before disconnecting the battery, turn the engine switch off.
If you are unsure what mode the engine switch was in before the battery discharged, be
especially careful when reconnecting the battery.
4
5
6
7

564
IS250_EE(OM53C51E)What to do if... (Troubleshooting)
What to do if... (Troubleshooting)
●If you lose your mechanical keys, new genuine mechanical keys can be made
by any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional. (→P. 114)
●If you lose your electronic keys, the risk of vehicle theft increases significantly.
Contact any authorized Lexus dealer or repairer, or another duly qualified
and equipped professional immediately. (→P. 1 1 7 )
●Is the electronic key battery weak or depleted? (→P. 4 4 2 )
●Is the engine switch in IGNITION ON mode?
When locking the doors, turn the engine switch off. (→P. 1 9 3 )
●Is the electronic key left inside the vehicle?
When locking the doors, make sure that you have the electronic key on your
person.
●The function may not operate properly due to the condition of the radio wave.
(→P. 1 3 2 )
●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. 1 2 2 )
If you have a problem, check the following before contacting any authorized
Lexus dealer or repairer, or another duly qualified and equipped professional.
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

565What to do if... (Troubleshooting)
IS250_EE(OM53C51E)
●The function to prevent the electronic 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. 1 2 7 )
●Did you press the engine switch while firmly depressing the brake pedal?
(→P. 1 9 2 )
●Is the shift lever in P? (→P. 1 9 4 )
●Is the electronic key anywhere detectable inside the vehicle? (→P. 1 3 0 )
●Is the steering wheel unlocked? (→P. 1 9 4 )
●Is the electronic key battery weak or depleted?
In this case, the engine can be started in a temporary way. (→P. 5 2 5 )
●Is the battery discharged? (→P. 5 2 7 )
●Is the engine switch in IGNITION ON mode?
If you cannot release the shift lever by depressing the brake pedal with the
engine switch in IGNITION ON mode. (→P. 5 2 3 )
●It is locked automatically to prevent theft of the vehicle. (→P. 1 9 4 ) The trunk lid is closed with the electronic key left inside
If you think something is wrong
The engine does not start
The shift lever cannot be shifted from P even if you depress the brake
pedal
The steering wheel cannot be turned after the engine is stopped

570Alphabetical index
IS250_EE(OM53C51E)
Card key...................................................... 112
Care ............................................... 404, 408
Aluminum wheels ............................. 405
Exterior....................................................404
Interior .................................................... 408
Seat belts............................................... 409
Cargo hooks ...........................................395
CD player ................................................. 319
Chains .......................................................289
Child restraint system ............................58
Baby seats, definition .......................... 59
Baby seats, installation .......................68
Child seats, definition.......................... 59
Child seats, installation.......................68
Installing CRS with ISOFIX
rigid anchors.......................................... 71
Installing CRS with seat belts..........68
Installing CRS with top strap ...........72
Junior seats, definition ........................ 59
Junior seats, installation ..................... 70
Child safety................................................. 57
Airbag precautions .............................. 43
Battery precautions ............. 425, 530
Child restraint system.........................58
How your child should
wear the seat belt .............................. 38
Installing child restraints .................... 67Moon roof precautions .................... 173
Power window lock switch ............ 167
Power window precautions........... 169
Rear door child-protectors ............ 122
Removed electronic key
battery precautions....................... 444
Seat belt precautions.......................... 40
Seat heater precautions ................. 387
Trunk precautions .............................. 128
Child-protectors .................................... 122
Cleaning....................................... 404, 408
Aluminum wheels.............................. 405
Exterior ................................................... 404
Interior.....................................................408
Seat belts ............................................... 409
Clock ......................................................... 398
Coat hooks.............................................. 402
Condenser ............................................. 422
Console box ........................................... 392
Cooling system ....................................... 421
Engine overheating ............................ 531
Cruise control
Cruise control ......................................225
Dynamic radar cruise control ......229
Cup holders ............................................ 393
Current fuel consumption ................... 101
Curtain shield airbags ............................ 41
Customizable features....................... 552
C

572Alphabetical index
IS250_EE(OM53C51E)
E-mail .........................................................353
Eco drive mode ..................................... 263
Eco Driving Indicator ........................... 104
Eco Driving Indicator Light ............... 102
Elapsed time ..............................................101
Electric Power Steering (EPS)........ 265
Function ..................................................265
Warning light ....................................... 477
Electronic key............................................ 112
Battery-saving function...................... 131
If the electronic key does not
operate properly ............................ 524
Replacing the battery....................... 442
Emergency, in case of
If the electronic key does not
operate properly ............................ 524
If the engine will not start .................521
If the shift lever cannot be
shifted from P ................................... 523
If the vehicle battery is
discharged......................................... 527
If the warning buzzer sounds ...... 476
If the warning light turns on .......... 476
If the warning message is
displayed ............................................ 482
If you have a flat tire ............. 496, 507
If you think something
is wrong............................................... 474
If your vehicle becomes stuck..... 534
If your vehicle has to be
stopped in an emergency.......... 467
If your vehicle needs to
be towed............................................ 468
If your vehicle overheats ................. 531Emergency brake signal.................... 266
Emergency flashers ............................. 466
Emergency tire puncture
repair kit ................................................ 507
Engine ....................................................... 540
ACCESSORY mode ....................... 193
Compartment ....................................... 417
Engine switch ........................................ 192
Hood ......................................................... 415
How to start the engine ................... 192
Identification number....................... 539
If the engine will not start ................. 521
Ignition switch (engine switch) ..... 192
Overheating .......................................... 531
Engine coolant......................................... 421
Capacity................................................. 543
Checking ................................................. 421
Preparing and checking
before winter.................................... 288
Engine coolant temperature
gauge ........................................................ 95
Engine immobilizer system .................. 77
Engine oil .................................................. 418
Capacity................................................... 541
Checking ................................................. 418
Preparing and checking
before winter.................................... 288
Engine switch ...........................................192
EPS (Electric Power Steering) ....... 265
Function.................................................. 265
Warning light........................................ 477
E

575Alphabetical index
IS250_EE(OM53C51E)
Identification
Engine......................................................539
Vehicle ....................................................539
Ignition switch (engine switch) ......... 192
Illuminated entry system ....................390
Indicators..................................................... 92
Initialization
Moon roof ............................................... 172
Multi-information display ................ 102
Power windows................................... 168
Tire pressure warning
system ..................................................428
Inside door handle lights ................... 389
Inside rear view mirror .......................... 161
Instrument panel light control ............98
Interior lights ...........................................390
Wattage................................................. 548
Intrusion sensor and tilt sensor ..........86
ISOFIX rigid anchors............................. 67
Jack
Positioning the jack.............................416
Vehicle-equipped jack ...... 497, 508
Jack handle .................................. 497, 508
Jam protection function
Moon roof .................................................171
Power window ..................................... 168Keyless entry
Smart entry & start
system........................................... 118, 125
Wireless remote control ........ 118, 125
Keys............................................................... 112
Battery-Saving Function .................... 131
Electronic key.......................................... 112
Engine switch ........................................ 192
If the electronic key does not
operate properly ............................ 524
Key number plate .................................. 112
Keyless entry................................. 118, 125
Mechanical key ...................................... 113
Replacing the battery .......................442
Warning buzzer.....................................119
Wireless remote control ................... 112
Knee airbags ............................................... 41
I
J
K

579Alphabetical index
IS250_EE(OM53C51E)
Radar cruise control (dynamic
radar cruise control) ........................ 229
Radiator .................................................... 422
Radio ............................................................317
Rear Crossing Traffic Alert .............. 278
Rear fog light ........................................... 213
Replacing light bulb............................461
Switch ........................................................ 213
Rear passengers’ seat belt
reminder lights.................................... 478
Rear seat.................................................... 149
Fold down the seatback ...................149
Luggage security system.................126
Rear personal lights .............................390
Wattage................................................. 548
Rear sunshade ...................................... 400
Operation............................................. 400
Reverse operation feature ........... 400
Rear turn signal lights..........................203
Replacing light bulbs........................ 454
Turn signal lever .................................203
Wattage................................................. 548
Rear view mirror
Inside rear view mirror....................... 161
Outside rear view mirrors...............163Rear view monitor system ................ 254
Rear window defogger ..................... 382
Refueling .................................................... 221
Capacity................................................. 540
Fuel types .............................................. 540
If the fuel filler door cannot
be opened ..........................................223
Opening the fuel tank cap.............223
Remote Touch
*
Replacing
Electronic key battery ......................442
Fuses ........................................................ 445
Light bulbs ............................................ 449
Tires.......................................................... 496
Rev indicator ............................................102
Rev peak ....................................................102
R
*: For vehicles with a navigation or multimedia system, refer to
“NAVIGATION AND MULTIMEDIA SYSTEM OWNER’S MANUAL”.