
6288-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
■Doors
Use the mechanical key ( P. 139)
in order to perform the following
operations:
Locks all the doors
Closes the windows and moon
roof (turn and hold)*
Unlocks all the doors
Opens the windows and moon roof (turn and hold)*
*: This setting must be customized at any authorized Lexus retailer or Lexus autho-
rized repairer, or an y reliable repairer.
■Trunk
Turn the mechanical key clockwise
to open.
If the electronic key does not operate properly
If communication between the electronic key and vehicle is interrupted ( P.
159) or the electronic key cannot be us ed because the battery is depleted, the
smart entry & start system and wireless remote control cannot be used. In
such cases, the doors and trunk can be opened and the hybrid system can be
started by following the procedure below.
Locking and unlocking the doors, unlocking the trunk and key linked
functions
1
2
3
4

6308-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
■Stopping the hybrid system
Shift the shift lever to P and pr ess the power switch as you normally do when stopping the
hybrid system.
■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. 549)
■Alarm (if equipped)
Using the mechanical key to lock th e 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 power switch modes
Release the brake pedal and press the power switch in step above. The hybrid system does not start and modes will be changed each time the switch is
pressed. ( P. 220)
■When the electronic key does not work properly
●Make sure that the smart entry & start system has not been deactivated in the
customization setting. If it is off, turn the function on.
(Customizable features: P. 657)
●Check if battery-saving mode is set. If it is set, cancel the function. (P. 158)
WARNING
■When using the mechanical key and operating the power windows or 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 op erate the mechanical key. It is possible for children and other passengers to get caught in the power window or moon roof.
3

6318-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D89E)
If you have a set of jumper (or booster) cables and a second vehicle with a 12-volt
battery, you can jump start your ve hicle by following the steps below.
Confirm that the electronic key is
being carried.
When connecting the jumper (or booster) cables, depending on the situa-
tion, the alarm may activate and doors
locked. (P. 94)
Open the hood ( P. 513) and fuse
box cover.
Remove the clips.
Push the tabs on either side to
detach the lock and lift the lid off
while pulling the lock plate.
If the 12-volt battery is discharged
The following procedures may be used to start the hybrid system if the 12-volt
battery is discharged.
You can also call any authorized Lexus retailer or Lexus authorized repairer,
or any reliable repairer.
1
2
1
2

6338-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D89E)
Maintain the engine speed of the second vehicle and start the hybrid system
of your vehicle by turning the power switch to ON mode.
Make sure the “READY” indicator comes on. If the indicator does not come
on, contact any authorized Lexus retailer or Lexus authorized repairer, or any
reliable repairer.
Once the hybrid system has started, remove the jumper cables in the exact
reverse order from which they were connected.
Once the hybrid system starts, have the vehicle inspected at any authorized
Lexus retailer or Lexus authorized repair er, or any reliable repairer 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 system while the hybrid system is off.
●Turn off any unnecessary electrical componen ts 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 w ill discharge gradually even when the vehicle
is not in use, due to natural discharge and the draining effects of certain electrical appli-
ances. If the vehicle is left for a long time, the 12-volt battery may discharge, and the hybrid system may be unable to start. (The 12-volt battery recharges automatically while
the hybrid system is operating.)
■When recharging or repl acing the 12-volt battery
●In some cases, it may not be possible to unlock the doors using the smart entry & start
system when the 12-volt battery is discharged. Use the wireless remote control or the
mechanical 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 retu rn to the mode it was in before the 12-volt battery was
discharged. Before disconnecting the 12-vol t battery, turn the power switch off.
If you are unsure what mode the power switch was in before the 12-volt battery dis- charged, be especially careful when reconnecting the 12-volt battery.
7
8
9

668
IS300h_EE(OM53D89E)
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 retailer or Lexu s authorized repairer, or any reliable
repairer. ( P. 140)
●If you lose your electronic keys, the risk of vehicle theft increases significantly.
Contact any authorized Lexus retailer or Lexus authorized repairer, or any
reliable repairer immediately. ( P. 143)
●Is the electronic key battery weak or depleted? (P. 549)
●Is the power switch in ON mode?
When locking the doors, turn the power switch off. (P. 220)
●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 du e to the condition of the radio wave.
( P. 159)
●Is the child-protector lock set?
The rear door cannot be opened from in side the vehicle when the lock is set.
Open the rear door from outside and then unlock the child-protector lock.
( P. 148)
If you have a problem, check the following before contacting any authorized
Lexus retailer or Lexus authorized re pairer, or any reliable repairer.
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

669What to do if... (Troubleshooting)
IS300h_EE(OM53D89E)
●The function to prevent the electronic key from being left inside the trunk will
operate and you can open the trunk as us ual. Take the key out from the trunk.
( P. 154)
●Did you press the power switch while firmly depressing the brake pedal?
( P. 219)
●Is the shift lever in P? (P. 221)
●Is the electronic key anywhere detectable inside the vehicle? (P. 157)
●Is the steering wheel unlocked? (P. 222)
●Is the electronic key battery weak or depleted?
In this case, the hybrid system can be started in a temporary way. (P. 629)
●Is the 12-volt battery discharged? (P. 631)
●Is the power switch in ON mode?
If you cannot release the shift lever by depressing the brake pedal with the
power switch in ON mode. ( P. 230)
●It is locked automatically to prevent theft of the vehicle. (P. 222)
The trunk lid is closed with the electronic key left inside
If you think something is wrong
The hybrid system 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 hybrid system is stopped

674Alphabetical index
IS300h_EE(OM53D89E)
Card key.................................................... 138
Care ............................................... 502, 506
Aluminum wheels ............................. 503
Exterior....................................................502
Interior .................................................... 506
Seat belts ................................................507
Cargo hooks.......................................... 488
Caution label .............................................. 81
CD player ................................................ 396
Chains ....................................................... 362
Child restraint system ............................ 59
Baby seats, definition ..........................60
Baby seats, installation .......................68
Child seats, definition..........................60
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 ........................60
Junior seats, installation ..................... 70
Child safety ................................................ 58
12-volt battery
precautions ........................... 524, 634
Airbag precautions ............................. 45
Child restraint system ........................ 59
How your child should
wear the seat belt.............................. 40
Installing child restraints .....................67
Moon roof precautions .................. 200
Power window lock switch ............ 193
Power window precautions........... 196
Rear door child-protectors ............148
Removed electronic key
battery precautions.........................551
Seat belt precautions........................... 42
Seat heater precautions ................. 479
Trunk precautions ..............................155
Child-protectors ................................... 148
Cleaning....................................... 502, 506
Aluminum wheels..............................503
Exterior ................................................... 502
Interior.....................................................506
Seat belts ............................................... 507
Clock ...........................................................491
Coat hooks.............................................. 495
C

676Alphabetical index
IS300h_EE(OM53D89E)
Doors .......................................................... 144
Automatic door locking and
unlocking system............................. 148
Door lock ................................................. 147
Open door warning buzzer ..........145
Open door warning
light ........................................................ 577
Outside rear view mirrors.............. 189
Rear door child-protector ............ 148
Side windows.........................................193
Drive information..................................... 116
Driver’s and front passenger’s
seat belt reminder light ................... 577
Driver’s seat position memory .......... 177
Driving ....................................................... 202
Break-in tips .........................................203
Correct driving posture .................... 36
Driving mode select switch ..........348
Hybrid vehicle driving tips ........... 358
Procedures ........................................... 202
Winter drive tips...................................361
Dynamic radar cruise control.......... 293
E-mail ........................................................ 429
ECB (Electronically Controlled
Brake System) .................................... 352
Eco drive mode ..................................... 348
Elapsed time .................................. 130, 134
Electric motor (traction motor) .......... 77
Electric Power Steering (EPS) ....... 352
Warning light....................................... 576
Electronic key ......................................... 138
Battery-saving function ....................158
If the electronic key does not
operate properly ............................ 628
Replacing the battery ...................... 549
E