Page 555 of 692

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.
Page 563 of 692

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.
Page 565 of 692

565
8When trouble arises
IS300h_EE(OM53D89E)
8-1. Essential information
Emergency flashe rs ..................566
If your vehicle has to
be stopped in an
emergency................................. 567
8-2. Steps to take in an
emergency
If your vehicle needs to
be towed .....................................568
If you think something is
wrong ........................................... 574
If a warning light turns
on or a warning buzzer
sounds.......................................... 575
If a warning message is
displayed ..................................... 581
If you have a flat tire
(vehicles with
emergency tire puncture
repair kit) ..................................... 610
If you have a flat tire
(vehicles with run-flat
tires).............................................. 625
If the hybrid sy stem will not
start ............................................... 626
If the electronic key does
not operate properly ............. 628
If the 12-volt battery is
discharged .................................. 631
If your vehicle overheats ......... 636
If the vehicle becomes
stuck ...............................................641
Page 567 of 692

5678-1. Essential information
8
When trouble arises
IS300h_EE(OM53D89E)
Steadily step on the brake pedal with both feet and firmly depress it.
Do not pump the brake pedal repeatedly as this will increase the effort required to
slow the vehicle.
Shift the shift lever to N.
If the shift lever is shifted to N
After slowing down, stop the vehicle in a safe place by the road.
Stop the hybrid system.
If the shift lever cann ot be shifted to N
Keep depressing the brake pedal with both feet to reduce vehicle speed as
much as possible.
To stop the hybrid system, press and
hold the power switch for 2 consec-
utive seconds or more, or press it
briefly 3 times or more in succes-
sion.
Stop the vehicle in a safe place by the road.
If your vehicle has to be stopped in an emergency
Only in an emergency, such as if it becomes impossible to stop the vehicle in
the normal way, stop the vehicl e using the following procedure:
1
2
3
4
3
Press and hold for 2 seconds or more
or press briefly 3 times or more
4
WARNING
■If the hybrid system has to be turned off while driving
Power assist for the steering wheel will be lost, making the steering wheel heavier to turn. Decelerate as much as possible before turning off the hybrid system.
5
Page 568 of 692
568
IS300h_EE(OM53D89E)
8-2. Steps to take in an emergency
The following may indicate a problem wi th your transmission. Contact any
authorized Lexus retailer or Lexus authoriz ed repairer, or any reliable repairer or
commercial towing service before towing.
●A warning message for the hybrid system is shown on the multi-information
display and the vehicle does not move.
●The vehicle makes an abnormal sound.
If your vehicle needs to be towed
If towing is necessary, we recommen d having your vehicle towed by any
authorized Lexus retailer or Lexus authorized repairer, or any reliable
repairer or commercial towing service, using a wheel-lift type truck or flatbed
truck.
Use a safety chain system for all towing, and abide by all state/provincial and
local laws.
Situations when it is necessary to contact dealers before towing
Page 572 of 692

5728-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
■While towing
If the hybrid system is off, the power assist for the brakes and steering will not function,
making steering and braking more difficult.
■Wheel nut wrench
Wheel nut wrench is installed in the trunk. ( P. 537)
WARNING
Observe the following precautions. Failure to do so may result in death or serious injury.
■When towing the vehicle
■While towing
●When towing using cables or chains, avoid sudden starts, etc. which place excessive
stress on the towing eyelets, cables or chains. The towing eyelets, cables or chains may become damaged, broken debris ma y hit people, and cause serious damage.
●Do not turn the power switch off.
There is a possibility that the steering wheel is locked and cannot be operated.
■Installing towing eyelet to the vehicle
Make sure that towing eyel et is installed securely.
If not securely installed, towing ey elet may come loose during towing.
Be sure to transport the vehicle with all four
wheels raised off the ground. If the vehicle is
towed with the tires contacting the ground, the
drivetrain and related parts may be damaged, an accident may occur due to a change in
direction of the vehicle or electricity generated
by the operation of the motor may cause a fire to occur depending on the nature of the dam-
age or malfunction.
Page 575 of 692

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.
Page 576 of 692

5768-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
SRS warning light Indicates a malfunction in:
• The SRS airbag system; or
• The seat belt pretensioner system Have the vehicle inspected by any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
ABS warning light
Indicates a malfunction in: • The ABS; or
• The brake assist system
Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.
Parking brake warning light (warning buzzer)*1
Indicates that the parking brake is engaged
Release the parking brake.
Electric power steering system warning light (warning buzzer) Indicates a malfunction in the EPS (Electric Power Steering) sys-
tem
Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer immediately.
(If equipped)
LDA (Lane Departure Alert) indicator
If the LDA indicato r is illuminated:
Indicates a malfunction in the LDA (Lane Departure Alert with
steering control) system. Check the warning message displayed on the multi-information
display. ( P. 581)
If the LDA indicator flashes:
Indicates that the vehicle has deviated from the lane (while the
LDA [Lane Departure Alert with stee ring control] system is oper- ating)
Check the area around the vehicle and return the vehicle to
between the lane lines.
Warning lightWarning light/Details/Actions