Page 521 of 628

5218-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
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, but 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 authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
Brake system warning light (warning buzzer)*1
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 dealer or repairer, or another duly qualified
and equipped professional. Continuing to drive the vehicle may
be dangerous.
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 dealer or
repairer, or another duly qualified and equipped professional
immediately.
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 dealer or repairer, or another duly qualified
and equipped professional.
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 dealer or
repairer, or another duly qualified and equipped professional
immediately.
Page 522 of 628

5228-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
SRS warning lightIndicates a malfunction in:
• The SRS airbag system; or
• The seat belt pretensioner system
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
ABS warning light
Indicates a malfunction in:
•The ABS; or
• The brake assist system
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
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 dealer or
repairer, or another duly qualified and equipped professional
immediately.
(Flashes)
(If equipped)
Pre-crash safety system warning light Indicates a malfunction in the PCS (Pre-Crash Safety system)
The warning light will operate as follows, even when the system is
not malfunctioning:
• The light will flash quickly when the system is operating.
(→ P. 3 0 2 )
• The light will turn on when the pre-crash safety system is dis- abled. ( →P. 3 0 3 )
• The light will turn on when the VSC (Vehicle Stability Control) system is disabled. ( →P. 2 9 8 )
• The light will flash when the system cannot temporarily be used.
(→ P. 5 3 6 )
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
Slip indicator
Indicates a malfunction in:
• The VSC (Vehicle Stability Control) system;
• The TRC (Traction Control) system; or
• The hill-start assist control system
The light will flash when the VSC, the TRC or the ABS system is
operating.
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
Warning lightWarning light/Details/Actions
Page 523 of 628

5238-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
Automatic headlight leveling system warning lightIndicates a malfunction in the au tomatic headlight leveling system
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
Open door warning light (warning buzzer)*2
Indicates that a door or the trunk is not fully closed
→ Check that all the doors and the trunk are closed.
Low fuel level warning light
Indicates that remaining fuel is a pproximately 10 L (2.6 gal., 2.2 Imp.
gal.) or less
→ Refuel the vehicle.
Driver’s and front passenger’s seat belt reminder light (warning
buzzer)
*3
Warns the driver and/or front passenger to fasten their seat belts
→ Fasten the seat belt.
If the front passenger’s seat is occupied, the front passenger’s
seat belt also needs to be fastened to make the warning light
(warning buzzer) turn off.
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. 5 2 7
Tire pressure warning light
When the light comes on:
Low tire inflation pressure such as
• Natural causes ( →P. 5 2 4 )
• Flat tire ( →P. 545, 559)
→ Adjust the tire inflation pre ssure 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 inflation pressure is adjusted, have the
system checked by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
When the light comes on af ter blinking for 1 minute:
Malfunction in the tire pressure warning system
→ Have the system checked by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
Warning lightWarning light/Details/Actions
Page 524 of 628

5248-2. Steps to take in an emergency
IS300h_EE(OM53D56E)*
1: Parking brake engaged warning buzzer:
→ P. 5 3 1
*2: Open door warning buzzer:
→ P. 5 2 9
*3: Seat belt warning buzzer:
The seat belt warning buzzer sounds to alert 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 will sound in a different tone for 90 more seconds.
■Passenger detection sensor, seat belt reminder and warning buzzer
●If luggage is placed on a passenger seat, the passenger detection sensor may cause the
warning light to flash and the warning buzzer to sound even if a passenger is not sitting
in the seat.
●If a cushion is placed on the seat, the sensor 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 indicator lamp will come on if the fuel tank becomes completely empty.
If the fuel tank is empty, refuel the vehicle immediately. The malfunction indicator lamp
will go off after several trips.
If the malfunction indicator lamp does not go off, contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional as soon as possible.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insu fficient or the voltage temporarily drops,
the electric power steering system warning light may come on and the warning buzzer
may sound.
■When the tire pressure warning light comes on
Carry out the following procedure after the tire temperature has lowered sufficiently.
●Check the tire inflation pressure and adjust to the appropriate level.
●If the warning light does not go out even after several minutes, check that the tire infla-
tion pressure is at the specifie d level and carry out initialization.
The warning light may come on again if the above operations are conducted without first
allowing the tire temperature to lower sufficiently.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air
leaks and tire inflation pressure changes caused by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (after a few minutes).
■Conditions that the tire pressure warning system may not function properly
→ P. 4 7 1
Page 525 of 628

5258-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
■If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the
power switch is turned to ON mode, have it checked by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.
CAUTION
■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 dealer
or repairer, or another duly qualified and equipped professional. The vehicle will
become extremely unstable during braking, and the ABS system may fail, which could
cause an accident resulting in death or serious injury.
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
If the steering wheel becomes heavier than us ual when operating, hold firmly and oper-
ate using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause a loss of
vehicle control and result in death or serious injury.
XVehicles 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 have 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.
XVehicles 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 in flation 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 dealer or repairer, or another duly qualified and equipped profes-
sional.
●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 system may not activate immediately.
Page 526 of 628
5268-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
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.
Page 527 of 628
5278-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
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 again after the following actions have been
performed, contact any authorized Lexu s dealer or repairer, or another duly
qualified and equipped professional.
If a warning message is displayed
If a warning is shown on the multi-information display, stay calm and perform
the following actions:
XExcept F SPORT models XF SPORT models (when the main
meter is in the center position)
XF SPORT models (when the main
meter is in the right-side position)
1
2
Page 528 of 628

5288-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
Warning message and warning buzzer list
Wa r n i n g m e s s a g eDetails/Actions
(If equipped)
Indicates that:
• There is a high possibility of a frontal collision; or
• The pre-crash braking function is operatingA buzzer also sounds.
→ Slow the vehicle by applying the brakes.
Indicates that the hybrid sy stem was stopped with the
shift lever not in P A buzzer also sounds.
→ Shift the shift lever to P.
Indicates that the hybrid system was stopped while driv-
ing
A buzzer also sounds.
→ Stop the vehicle in a safe place such as the shoulder
of a road.
(If equipped)
Indicates that your vehicle is nearing the vehicle ahead
(in vehicle-to-vehicle distance mode)
A buzzer also sounds.
→ Slow the vehicle by applying the brakes.
(If equipped)
Alerts the driver that the vehicle has deviated from the
lane (while the LDA [Lane Departure Alert] system is
operating)
The lane line on the side the vehicle has deviated from
flashes in yellow.
The warning buzzer sounds continuously.
→ Check around the vehicle and back to inside of the
lane lines.
(Flashes)
(Flashes)
(Flashes)