
2814-5. Using the driving support systems
4
Driving
IS300h_EE(OM53D89E)
WARNING
■Before using LDA system
Do not rely solely upon the LDA system. The LDA system does not automatically drive
the vehicle or reduce the amount of attention that must be paid to the area in front of
the vehicle. The driver must always assume full responsibility for driving safely by pay- ing careful attention to the surrounding cond itions and operating the steering wheel to
correct the path of the vehicle. Also, th e driver must take adequate breaks when
fatigued, such as from driving for a long period of time. Failure to perform appropriate driving operat ions and pay careful attention may lead to
an accident, resulting in death or serious injury.
■To avoid operating LDA system by mistake
When not using the LDA system, use the LDA switch to turn the system off.
■Situations unsuitable for LDA system
Do not use the LDA system in the following situations. The system may not operate properly and le ad to an accident, resulting in death or
serious injury.
●A spare tire, tire chains, etc. are equipped.
●When the tires have been excessively worn, or when the tire inflation pressure is low.
●Tires which differ by structure, manufacturer, brand or tread pattern are used.
●Objects or patterns that could be mistaken for white (yellow) lines are present on the side of the road (guardrails, cu rbs, reflective poles, etc.).
●Vehicle is driven on a snow-covered road.
●White (yellow) lines are difficult to see due to rain, snow, fog, dust, etc.
●Asphalt repair marks, white (yellow) line marks, etc. are present due to road repair.
●Vehicle is driven in a temporary lane or restricted lane due to construction work.
●Vehicle is driven on a road surface which is slippery due to rainy weather, fallen snow, freezing, etc.
●Vehicle is driven in traffic lanes ot her than on highways and freeways.
●Vehicle is driven in a construction zone.
●When your vehicle is towing a trailer or during emergency towing
■Preventing LDA system malfunctions and operations performed by mistake
●Do not modify the headlights or place stickers, etc. on the surface of the lights.
●Do not modify the suspension etc. If the suspension etc. needs to be replaced, con-
tact your authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer.
●Do not install or place anything on the hood or grille. Also, do not install a grille guard
(bull bars, kangaroo bar, etc.).
●If your windshield needs repairs, contact your authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.

4986-5. Using the other interior features
IS300h_EE(OM53D89E)
WARNING
■When the Emergency Call may not be made
●Any of the followings may occur. In such cases, report to the Public Safety Answering
Point (PSAP) by other means su ch as nearby public phones.
• It may sometimes be difficult to connect to the public Safety Answering Point (PSAP) even in the reception area of t he cellular phone due to the reception level,
or if the line is busy. In such cases, you may not be able to connect to the Public
Safety Answering Point (PSAP) and thus will not be able to make emergency calls and report to the emergency departments even though the system tries to con-
nect to the Public Safety Answering Point (PSAP).
• When the vehicle is out of the cellular phone service area, the Emergency Call cannot be made.
• When any related equipment (such as the “SOS” button panel, indicator lights,
microphone, speaker, DCM, antenna, or any wires connecting the equipment.) has an abnormality, is damaged or brok en, the Emergency Call cannot be made.
• During the Emergency Call, the system makes repeated attempts to connect to
the Public Safety Answerin g Point (PSAP). However, if it cannot connect to the Public Safety Answering Point (PSAP) due to poor radio wave reception, the sys-
tem may not be able to connect to the ce llular network and the call may finish with-
out connecting. The red indi cator light will blink for approximately 30 seconds to indicate this disconnection.
• This device may not function if a shock is applied to it.
●If the 12-volt battery’s voltage decreases or there is a disconnection, the system may
not be able to access the Public Safety Answering Point (PSAP).
■When replacing DCM to a new one
ERA-GLONASS have to be activated. Contac t any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.

5557-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
■After a fuse is replaced
●If the lights do not turn on even after the fuse has been replaced, a bulb may need
replacement. ( P. 556)
●If the replaced fuse blows again, have the vehicle inspected by any authorized Lexus
retailer or Lexus authorized re pairer, or any reliable repairer.
■If there is an overload in a circuit
The fuses are designed to blow, protecting the wiring harness from damage.
■When replacing light bulbs
Lexus recommends that you use genuine Lexus products designed for this vehicle. Because certain bulbs are connected to circui ts designed to prevent overload, non-gen-
uine parts or parts not designed for this vehicle may be unusable.
WARNING
■To prevent system breakdowns and vehicle fire
Observe the following precautions.
Failure to do so may cause damage to th e vehicle, and possibly a fire or injury.
●Never use a fuse of a higher amperage rating than that indicated, or use any other object in place of a fuse.
●Always use a genuine Lexus fuse or equivalent.
Never replace a fuse with a wi re, even as a temporary fix.
●Do not modify the fuses or fuse boxes.
■Fuse box near the power control unit
Never check or replace the fuses as there are high voltage parts and wiring near the fuse box.
Doing so may cause electric shock, re sulting in death or serious injury.
NOTICE
■Before replacing fuses
Have the cause of electrical overload de termined and repaired by any authorized
Lexus retailer or Lexus authorized repairer, or any reliable repairer as soon as possible.

5637-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
WARNING
■Replacing light bulbs
●Turn off the lights. Do not attempt to replace the bulb immediately after turning off the
lights.
The bulbs become very hot and may cause burns.
●Do not touch the glass portion of the light bu lb with bare hands. When it is unavoid-
able to hold the glass portion, use and hold with a clean dry cloth to avoid getting
moisture and oils on the bulb. Also, if the bulb is scratched or dropped, it may blow out or crack.
●Fully install light bulbs and any parts used to secure them. Failure to do so may result
in heat damage, fire, or water entering th e headlight unit. This may damage the head- lights or cause condensation to build up on the lens.
■To prevent damage or fire
●Make sure bulbs are fully seated and locked.
●Check the wattage of the bulb before installing to prevent heat damage.
NOTICE
■When replacing the outer foot lights
If the front window is stop ping you from conducting the replace operation properly,
open the window on the side you are working on to allow you enough space to work.
Continuing the operation without giving yourself enough space to work could lead you to scratch the vehicle.

5758-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D89E)
If a warning light turns on or a warning buzzer
sounds
Calmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, bu t then goes off, this does not necessar-
ily indicate a malfunction in the system . However, if this continues to occur,
have the vehicle inspected by any au thorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
Brake system warning light Indicates that:
• The brake fluid level is low; or
• The brake system is malfunctioning Immediately stop the vehicle in a safe place and contact any
authorized Lexus retailer or Lexus authorized repairer, or any
reliable repairer. Continuing to drive the vehicle may be dan- gerous.
Brake system warning light
Indicates a malfunction in:
• The regenerative braking system; or
• The electronically controlled brake system Have the vehicle inspected by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
(If equipped)
Charging system warning light
Indicates a malfunction in the vehicle’s charging system Immediately stop the vehicle in a safe place and contact any
authorized Lexus retailer or Lexus authorized repairer, or any
reliable repairer.
Malfunction indicator lamp Indicates a malfunction in:
• The hybrid system;
• The emission control system (if equipped); • The electronic engine control system; or
• The electronic throttle control system
Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.

5788-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
*1: Parking brake engaged warning buzzer:
P. 587
*2: Open door warning buzzer:
P. 583
*3: Seat belt warning buzzer:
The seat belt warning buzzer sounds to al ert the driver, front passenger and rear pas-
sengers that his or her seat belt is not fastened. The buzzer sounds for 30 seconds
after the vehicle reaches a speed of 20 km/h (12 mph). Then, if the seat belt is still unfastened, the buzzer w ill sound in a different tone for 90 more seconds.
■Front passenger detection sensor, seat belt reminder and warning buzzer
●If luggage is placed on the front passenger seat, the front passenger detection sensor
may cause the warning light to flash and the warning buzzer to sound even if a passen-
ger is not sitting in the seat.
●If a cushion is placed on the seat, the sens or may not detect a passenger, and the warn-
ing light may not operate properly.
■If the malfunction indicator lamp comes on while driving
The malfunction indicato r lamp will come on if the fuel tank becomes completely empty.
If the fuel tank is empty, refuel the vehi cle immediately. The malfunction indicator lamp
will go off after several trips.
If the malfunction indicator lamp does not go off, contact any authorized Lexus retailer or
Lexus authorized repairer, or any re liable repairer as soon as possible.
Rear passengers’ seat belt reminder lights (warning buzzer)*3
Warns the rear passengers to fasten their seat belts
Fasten the seat belt.
Master warning light
A buzzer sounds and the warning light comes on and flashes to indicate that the master warning system has detected a malfunc-
tion.
P. 581
Tire pressure warning light When the light comes on:
Low tire inflation pressure such as
• Natural causes ( P. 579) •Flat tire ( P. 610, 625)
Adjust the tire inflation pressure to the specified level.
The light will turn off after a few minutes. In case the light does not turn off even if the tire inflat ion pressure is adjusted, have the
system checked by any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer. When the light comes on after blinking for 1 minute:
Malfunction in the tire pressure warning system
Have the system checked by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer.
Warning lightWarning light/Details/Actions

5808-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
WARNING
■If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediately and contact any authorized Lexus retailer
or Lexus authorized repairer, or any re liable repairer. The vehicle will become
extremely unstable during braking, and the ABS system may fail, which could cause an accident resulting in de ath or serious injury.
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy. When steering wheel operations are heavier than usual, grip the steering wheel firmly
and operate it using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precaution s. Failure to do so could cause a loss of
vehicle control and result in death or serious injury.
Vehicles with an emergency tire puncture repair kit
●Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pressure
immediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust- ment, it is probable that you ha ve a flat tire. Check the tires. If a tire is flat, repair the
flat tire by using emergency tire puncture repair kit.
●Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you could lose control of the steering wheel or the brakes.
Vehicles with run-flat tires
●Decelerate to the lowest appropriate speed as soon as possible. Do not drive over 60 km/h (37 mph).
●Check and adjust the tire inflation pressure immediately.
●If the tire pressure warning light comes on even after tire inflation pressure adjust- ment, it is probable that you have a flat tire. Have the tire replaced by the nearest
authorized Lexus retailer or Lexus author ized repairer, or any reliable repairer.
●Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you could lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning syst em may not activate immediately.
NOTICE
■To ensure the tire pressure warning system operates properly
Do not install tires with different specifications or makers, as the tire pressure warning system may not operate properly.

5818-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D89E)
Master warning light
The master warning light also comes on or flashes in order to indicate that a message
is currently being displayed on the multi-information display.
Multi-information display
If any of the warning lights come on ag ain after the following actions have been
performed, contact any authorized Lexus retailer or Lexus authorized repairer,
or any reliable repairer.
If a warning message is displayed
If a warning is shown on the multi-info rmation display, stay calm and perform
the following actions:
Except F SPORT modelsF SPORT models (when the main
meter is in the center position)
F SPORT models (when the main
meter is in the right-side position)
1
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