2018 LEXUS RX450h light

651
8When trouble arises
RX450h_RX450hL _U_OM48F85U 8-1. Essential information
Emergency flashers .................. 652
If your vehicle has
to be stopped in
an emergency .......................... 653
8-2. Steps to take in
an emergency
If your vehicle needs
to be towed................................ 654
If you think something is
wrong ........................................... 659
If a warning light turns on
or a warning buzzer
sounds..........................................660
If a warning message is
displayed..................................... 667
If you have a flat tire .................. 673
If the hybrid system will
not start .......................................690
If the electronic key does
not operate properly ............. 692
If the 12-volt battery is
discharged ................................. 695
If your vehicle overheats ......... 702
If the vehicle becomes
stuck ............................................. 706

652
RX450h_RX450hL _U_OM48F85U8-1. Essential information
Press the switch. All the turn signal lights will flash. To turn
them off, press the switch once again.
■
Emergency flashers
If the emergency flashers are used for a long time while the hybrid system is not operat-
ing (while the “READY” indicator is not illu minated), the 12-volt battery may discharge.
Emergency flashers The emergency flashers are used to warn other drivers when the vehicle has
to be stopped on the road due to a breakdown, etc.

660 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UIf 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 inspecte d by your Lexus dealer.
Warning light and warning buzzer list Warning light Warning light/Details/Actions(U.S.A.)
(Canada)
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 your
Lexus dealer. Continuing to drive the vehicle may be dangerous.
Brake system warning light
Indicates a malfunction in:
• The regenerative braking system;
• The electronically controlled brake system; or
• The electric parking brake
→ Have the vehicle inspected by your Lexus dealer 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 your
Lexus dealer. Continuing to drive the vehicle may be dangerous. (U.S.A.)
(Canada)
Malfunction indicator lamp
Indicates a malfunction in:
• The hybrid system;
• The electronic engine control system; or
• The electronic throttle control system
→ Have the vehicle inspected by your Lexus dealer immediately.
SRS warning light
Indicates a malfunction in:
• The SRS airbag system;
• The front passenger occupant classification system; or
• The seat belt pretensioner system
→ Have the vehicle inspected by your Lexus dealer immediately.

6618-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U (U.S.A.)
(Canada)
ABS warning light
Indicates a malfunction in:
• The ABS; or
• The brake assist system
→ Have the vehicle inspected by your Lexus dealer immediately. (Flashes)
(U.S.A.)
(Flashes)
(Canada)
Parking brake indicator
It is possible that the parking br ake is not fully engaged or released
→ Operate the parking brake switch once again.
This light comes on when the parking brake is not released. If the
light turns off after the parking brak e is fully released, the system is
operating normally. (Flashes)
Brake hold operated indicator
Indicates a malfunction in the brake hold system
→ Have the vehicle inspected by your Lexus dealer 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 your Lexus dealer immediately.
LKA indicator
Indicates a malfunction in the LKA (Lane-Keeping Assist)
→ When “Lane Keeping Assist Unavailable” is displayed on the
multi-information display, turn the LKA system off, drive the
vehicle for a short time, and then turn the LKA system back on.
( → P. 301)
When a message other than above is displayed, follow the
instructions displayed in the message.
Slip indicator
When the warning lig ht is illuminated:
Indicates a malfunction in:
• The VSC system;
• The TRAC system;
• The Trailer Sway Control; or
• The hill-start assist control system
→ Have the vehicle inspected by your Lexus dealer immediately.
When the warning light flashes:
Indicates that the ABS, VSC, TR AC or Trailer Sway Control sys-
tem is operatingWarning light Warning light/Details/Actions

662 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U (Flashes or illuminates)
PCS warning light
Indicates a malfunction in the PCS (Pre-Collision System) or that
the system is temporarily unavailable due to the vehicle being
extremely hot/cold, or dirt around a front sensor, etc.
( → P. 296, 671)
→ Follow the instructions displaye d on the multi-information dis-
play. ( → P. 296, 671)
If the PCS (Pre-Collision System ) or VSC (Vehicle Stability Con-
trol) system is disabled, the PC S warning light will illuminate.
→ P. 296 (Flashes)
ICS OFF indicator
When a buzzer sounds:
Indicates a malfunction in the Intelligent Clearance Sonar system
→ Have the vehicle inspected by your Lexus dealer immediately.
When a buzzer does not sound:
Indicates that the system is temporarily unavailable, possibly due to
a sensor being dirty or covered with ice, etc.
→ Clear the dirt, etc.
Low fuel level warning light
Indicates that remaining fuel is approximately 2.9 gal. (11.0 L,
2.4 Imp. gal.) or less
→ Refuel the vehicle.
Driver’s and front passenger’s seat belt reminder light (warning
buzzer)
* 1
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. (RX450h)
(RX450hL)
Rear passengers’ seat belt reminder light (warning buzzer)
* 2
Warns the rear passengers to fasten their seat belts
→ Fasten the seat belt.
Tire pressure warning light
Indicates the following:
• Low tire pressure due to flat tire;
• Low tire pressure due to natural causes; or
• The tire pressure warnin g system is malfunctioning
→ Immediately stop the vehicle in a safe place.
Handling method ( → P. 664)Warning light Warning light/Details/Actions

6638-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U* 1
: Driver’s and front passenger’s seat belt warning buzzer:
The driver’s seat belt warning buzzer sounds to alert the driver that his or her seat belt
is not fastened. Once the power switch is turned to ON mode, the buzzer sounds for
6 seconds. If the vehicle reaches a speed of 12 mph (20 km/h), the buzzer sounds
once. If the seat belt is still unfastened af ter 24 seconds, the buzzer will sound inter-
mittently for 10 seconds. Then, if the seat belt is still unfa stened, the buzzer will sound
in a different tone for 20 more seconds.
The front passenger’s seat belt warning buzzer sounds to alert the front passenger
that his or her seat belt is not fastened. Th e buzzer sounds once if the vehicle reaches
a speed of 12 mph (20 km/h). If the seat belt is still unfastened after 24 seconds, the
buzzer will sound intermittently for 10 seconds. Then, if the seat belt is still unfastened,
the buzzer will sound in a different tone for 20 more seconds.
* 2
: Rear passengers’ seat belt warning buzzer:
The rear passengers’ seat belt warning bu zzer sounds to alert the rear passengers
that his or her seat belt is not fastened. The buzzer so unds for 6 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 24 more seconds. Master warning light
A buzzer sounds and the warning light comes on and flashes to
indicate that the master warnin g system has dete cted a malfunc-
tion.
→ P. 667Warning light Warning light/Details/Actions

664 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors, side
impact sensors (front door), side impact se nsors (rear), driver’s seat position sensor,
driver’s seat belt buckle sw itch, front passenger occupant classification system (ECU and
sensors), “AIR BAG ON” indicator light, “A IR BAG OFF” indicator light, front passen-
ger’s seat belt buckle switch, driver’s seat belt pretension er, front passenger’s seat belt
pretensioner and force limiter, airbags, in terconnecting wiring and power sources.
( → P. 36) ■
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 sittin g 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. ■
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. ■
If the malfunction indicator lamp comes on while driving
First check the following: ●
Is the fuel tank empty?
If it is, fill the fu el tank immediately.●
Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving trips.
If the light does not go off even after severa l trips, contact your Lexus dealer as soon as
possible. ■
When the tire pressure warning light comes on
Inspect the tires to check if a tire is punctured.
If a tire is punctured: → P. 673
If none of the tires are punctured:
Turn the power switch off then turn it to ON mode. Check if the tire pressure warning
light comes on or blinks. 
If the tire pressure warning light comes on
After the temperature of the tires has lowere d sufficiently, check the inflation pressure
of each tire and adjust th em to the specified level.
If the warning light does not turn off even after several minutes have elapsed, check
that the inflation pressure of each tire is at the specified level an d perform initialization.
( → P. 613)
If the warning light does not turn off severa l minutes after the init ialization has been per-
formed, have the vehicle inspected by your Lexus dealer immediately. 
If the tire pressure wa rning light blinks for 1 minute then stays on
There may be a malfunction in the tire pressure warnin g system. Have the vehicle
inspected by your Lexus dealer immediately. 1
2

6658-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U■
The tire pressure warning light ma y 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 caus ed by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (aft er 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. Replace the spare tire with the repaired tire
and adjust the tire inflation pressure. The tire pressure warnin g light will go off after a few
minutes. ■
Conditions that the tire pressure wa rning system may not function properly
→ P. 616 ■
Warning buzzer
In some cases, the buzzer ma y not be heard due to being in a noisy location or audio
sound. ■
Customization
Some functions can be customized. ( → P. 736)
WARNING ■
If both the ABS and the brake sy stem warning lights remain on
Stop your vehicle in a safe place immediat ely and contact your Lexus dealer. The vehi-
cle will become extremely unstable during br aking, and the ABS system may fail, which
could cause an accident resultin g in death or serious injury.■
When the electric power steering system warning light comes on
When the light comes on yellow, the assist to the power steering is restricted. When the
light comes on red, the assist to the power steering is lost and ha ndling operations of
the steering wheel 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.●
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 Lexus dealer. ●
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.