
4777-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
ABS warning lightIndicates 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)
PCS (Pre-Crash Safety system) warning light
●When the warning light flashes (and a buzzer sounds):
Indicates a malfunction in the PCS (Pre-Crash Safety system)
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
●When the warning light flashes (and a buzzer does not sound):
Indicates that the PCS (Pre-Crash Safety system) is temporarily
unavailable, possibly due to either of the following:
• An area around the radar sensor or camera sensor being dirty
or covered with condensation, ice, stickers, etc.
→ Clear the dirt, condensation, ice, stickers, etc.
(→ P. 263, 284, 292)
• Radar sensor or camera sensor being outside of its operational
condition range. (temperature etc.)
→ If operational condition (tempera ture etc.) is satisfied, PCS
(Pre-Crash Safety system) becomes to be available.
●When the warning light is illuminated:
Either the VSC (Vehicle Stability Control) system or PCS (Pre-
Crash Safety system) is disabled or both are disabled.
→ To enable the PCS (Pre-Crash Safety system), enable both
the VSC system and PCS (Pre-Crash Safety system).
(→ P. 2 8 0 , 3 4 7 )
Slip indicator
Indicates a malfunction in:
• The VSC system;
• The TRC system; or
• The hill-start assist control system
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
The light will flash when the VSC, TRC or ABS system is operating.
Warning lightWarning light/Details/Actions

4797-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
*: Driver’s and front passenger’s seat belt buzzer:The driver’s and front passenger’s seat belt buzzer sounds to alert the driver and front
passenger that his or her seat belt is not fastened. The buzzer sounds intermittently 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.
■Front passenger detection sensor, seat belt reminder and warning buzzer
●If luggage is placed on the front passenge r 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 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 (if equipped)
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.
(If equipped)
Tire pressure warning light When the light comes on:
Low tire inflation pressure such as
• Natural causes ( →P. 4 8 0 )
• Flat tire ( →P. 5 1 7 , 5 2 8 )
→ 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

4807-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
■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).
■When a tire is replaced with a spare tire
The compact spare tire is not equipped with a tire pressure warning valve and transmit-
ter. If a tire goes flat, the tire pressure warning light will not turn off even though the flat
tire has been replaced with the spare tire.
■Conditions that the tire pressure warning system may not function properly
→P. 4 3 6
■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 because of noisy place or an audio sound.
WA R N I N G
■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.
●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, change it
with the spare tire and have the flat tire repaired by the nearest any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional.
●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.

4837-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
(If equipped)
Indicates that your vehicle is nearing the vehicle ahead
(in vehicle-to-vehicle distance control mode)At the same time, will appear on the head-up dis-
play (the image flashes).
A buzzer also sounds.
→ Slow the vehicle by applying the brakes.
(If equipped)
Indicates that the vehicle has deviated from the lane
(while the LKA (Lane-Keeping Assist) or LDA [Lane
Departure Alert with steering control] system are oper-
ating)
The lane line on the side the vehicle has deviated from
flashes in amber.
At the same time, will appear on the head-
up display (the image flashes).
A buzzer also sounds.
→ Check around the vehicle and back to inside of the
lane lines.
Indicates a malfunctio n in the brake system
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Continuing to drive the vehicle may be dangerous.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)

4897-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
Indicates an attempt was made to release the parking
brake without depressing the brake pedalA buzzer also sounds.
→ Release the parking brake while depressing the
brake pedal.
Indicates that the shift position was changed and drive
start control was operated while depressing the acceler-
ator pedal
A buzzer also sounds.
→ Momentarily release the accelerator pedal.
Indicates an attempt was made to shift to 1st gear with
the shift position in S while on a slippery surface
The vehicle will not shift down from 2nd gear.
A buzzer also sounds.
→ Drive the vehicle in 2nd gear or higher.
(If equipped)
Indicates that the LDA (Lane Departure Alert with steer-
ing control) system has dete rmined that the driver does
not have their hands on the steering wheel while the
steering control function is on
→ Firmly hold the steering wheel.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)

4907-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
(If equipped)
Indicates that the LKA (Lane-Keeping Assist) system has
determined that the driver does not have their hands on
the steering wheel while the steering control function is
on
→Firmly hold the steering wheel.
(If equipped)
Indicates that steering control function is temporarily
canceled due to the LDA (Lane Departure Alert with
steering control) system de termining that the driver
does not have their hands on the steering wheel while
the steering control function is on
→ Firmly hold the steering wheel.
(If equipped)
Indicates that steering control function is temporarily
canceled due to the LKA (Lane-Keeping Assist) system
determining that the driver does not have their hands on
the steering wheel while the steering control function is
on
A buzzer also sounds.
→ Firmly hold the steering wheel.
Wa r n i n g m e s s a g eDetails/Actions

4957-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
(If equipped)
Indicates a malfunction in the LDA (Lane Departure
Alert with steering control) systemA buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
(If equipped)
Indicates a malfunction in the LKA (Lane-Keeping
Assist) system
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
(If equipped)
The operation conditions of the camera sensor (temper-
ature, etc.) are not met.
→When the operation conditions of the camera sen-
sor (temperature, etc.) are met, the following sys-
tems will become available.
• PCS (Pre-Crash Safety system)
• LKA (Lane-Keeping Assist) system
• LDA (Lane Departure Alert with steering control) system
• RSA (Road Sign Assist)
• AHS (Adaptive High-beam System)
•Automatic High Beam
(If equipped)
Indicates that the system is temporarily unavailable due
to a malfunction in a sensor other than the camera sen-
sor
A buzzer also sounds.
→ Turn the LDA (Lane Departure Alert with steering
control) system off, wait for a little while, and then
turn the LDA (Lane Departure Alert with steering
control) system back on.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)

4967-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
(If equipped)
Indicates that the system is temporarily unavailable due
to a malfunction in a sensor other than the camera sen-
sor A buzzer also sounds.
→ Turn the LKA (Lane-Keeping Assist) system off, wait
for a little while, and then turn the LKA (Lane-Keep-
ing Assist) system back on.
(If equipped)
Dirt, rain, condensation, ice, snow, etc., are present on
the windshield in front of the camera sensor.
The following systems will be temporarily unusable.
• PCS (Pre-Crash Safety system)
• LKA (Lane-Keeping Assist) system
• LDA (Lane Departure Alert with steering control)
system
• RSA (Road Sign Assist)
• AHS (Adaptive High-beam System)
•Automatic High Beam
→ Turn the system off, remove any dirt, rain, condensa-
tion, ice, snow, etc., from the windshield, and then
turn the system back on.
(If equipped)
Indicates a malfunction in the PCS (Pre-Crash Safety
system)
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
(If equipped)
Indicates a malfunction in the BSM (Blind Spot Monitor)
system
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)
(Flashes)