
4926-3. Do-it-yourself maintenance
RX450h_U_OM0E013U
■Situations in which the tire pressure warning system may not operate properly
●In the following cases, the tire pressure warning system may not operate properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains etc. are equipped.
• If a window tint that affects th e radio wave signals is installed.
• If there is a lot of snow or ice on the vehi cle, particularly around the wheels or wheel
housings.
• If the tire inflation pressure is extr emely higher than the specified level.
• If wheel without the tire pressure warning valve and transmitter is used.
• If the ID code on the tire pressure warning valves and transmitters is not registered in the tire pressure warning computer.
●Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large display, air-
port or other facility that generates st rong radio waves or electrical noise.
• When carrying a portable radio, cellular phone, cordless phone or other wireless
communication device.
If tire position information is not correctl y displayed due to the radio wave conditions,
the display may be corrected by driving and changing the radio wave conditions.
●When the vehicle is parked, the time taken for the warning to start or go off could be
extended.
●When tire inflation pressure declines rapidly for example when a tire has burst, the
warning may not function.
■The initialization operation
●Make sure to carry out initialization afte r adjusting the tire inflation pressure.
Also, make sure the tires are cold before carryi ng out initialization or tire inflation pres-
sure adjustment.
●If you have accidentally turned the power switch off during initialization, it is not neces-
sary to press the reset switch again as initialization will restart automatically when the
power switch has been turned to ON mode for the next time.
●If you accidentally press the re set switch when initialization is not necessary, adjust the
tire inflation pressure to the specified leve l when the tires are cold, and conduct initial-
ization again.
●While the position of each tire is being de termined and the inflation pressures are not
being displayed on the multi-info rmation display, if the inflation pressure of a tire drops,
the tire pressure warning light will come on.

5076-3. Do-it-yourself maintenance
6
Maintenance and care
RX450h_U_OM0E013U
■Use a CR2032 lithium battery
●Batteries can be purchased at your Lexus dealer, local electrical appliance shops or
camera stores.
●Replace only with the same or equivalent type recommended by the manufacturer.
●Dispose of used batteries according to the local laws.
■If the electronic key battery is depleted
The following symptoms may occur:
●The smart access system with push-button start and wireless remote control will not
function properly.
●The operational range will be reduced.
WARNING
■Removed battery and other parts
These parts are small and if swallowed by a child, they can cause choking. Keep away
from children. Failure to do so coul d result in death or serious injury.
NOTICE
■For normal operation after replacing the battery
Observe the following precautions to prevent accidents:
●Always work with dry hands.
Moisture may cause the battery to rust.
●Do not touch or move any other co mponent inside the remote control.
●Do not bend either of the battery terminals.

527
7When trouble arises
RX450h_U_OM0E013U
7-1. Essential informationEmergency flashers ..................528
If your vehicle has to be stopped in an
emergency................................. 529
7-2. Steps to take in an emergency
If your vehicle needs to be towed ...........................................530
If you think something is wrong ...........................................535
If a warning light turns on or a warning buzzer
sounds.......................................... 536
If a warning message is displayed..................................... 543
If you have a flat tire .................. 549
If the hybrid sy stem will not
start ................................................ 561
If the shift lever cannot be shifted from P............................ 563
If the electronic key does not operate properly ............. 564
If the 12-volt battery is discharged .................................568
If your vehicle overheats ......... 574
If the vehicle becomes stuck ............................................. 578

5377-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
(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/LDA indicator
Indicates a malfunction in the LKA (Lane-Keeping Assist)/LDA
(Lane Departure Alert with steering control)
When “Lane Keeping Assist Unav ailable” or “Lane Departure
Alert Unavailable” is displayed on the multi-information display,
turn the LKA/LDA system off, drive the vehicle for a short time,
and then turn the LKA/LDA system back on. ( P. 296, 305)
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 operating
Warning lightWarning light/Details/Actions

5427-2. Steps to take in an emergency
RX450h_U_OM0E013U
WARNING
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold and
inflated to the inflation pressure recomm ended by the vehicle manufacturer on the
vehicle placard or tire inflation pressure label (tire and load information label). (If your
vehicle has tires of a different size than the size indicated on the vehicle placard or tire
inflation pressure label [tire and load in formation label], you should determine the
proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle has been equipped with a tire pressure moni-
toring system (TPMS-tire pressure warning system) that illuminates a low tire pressure
telltale (tire pressure warning light) when on e or more of your tires is significantly
under-inflated. Accordingly, when the low ti re pressure telltale (tire pressure warning
light) illuminates, you should st op and check your tires as soon as possible, and inflate
them to the proper pressure. Driving on a significantly under-inflat ed tire causes the
tire to overheat and can lead to tire failure. Under-inflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle’s handling and stopping ability.
Please note that the TPMS (tire pressure wa rning system) is not a substitute for proper
tire maintenance, and it is the driver’s responsibility to maintain correct tire pressure,
even if under-inflation has not reached the le vel to trigger illumination of the TPMS low
tire pressure telltale (tir e pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system) mal-
function indicator to indicate when the system is not operating properly. The TPMS
(tire pressure warning system) malfunction indi cator is combined with the low tire pres-
sure telltale (tire pressure warning light). When the system detects a malfunction, the
telltale will flash for approximately one mi nute and then remain continuously illumi-
nated. This sequence will cont inue upon subsequent vehicle start-ups as long as the
malfunction exists. When the malfunction indicator is illuminated, the system may not
be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a variety of reasons,
including the installation of replacement or alternate tires or wheels on the vehicle that
prevent the TPMS (tire pressure warning system) from functioning properly. Always
check the TPMS (tire pressure warning system) malfunction telltale after replacing one
or more tires or wheels on your vehicle to ensure that the replacement or alternate
tires and wheels allow the TPMS (tire pressure warning system) to continue to function
properly.
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.

5457-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
Take the appropriate actions as instructed in the message displayed.
If any of the following messages are displa yed, also refer to this Owner’s Manual.
■If “Hybrid System Overheated Reduced Output Power” is shown
This message may be displayed when driving under severe operating condi-
tions.
(For example, when driving up a long steep hill.)
Handling method: P. 574
■If “Hybrid Battery Low Shift Ou t of N to Recharge” is shown
Message is displayed when the remainin g charge for the hybrid battery (trac-
tion battery) is low.
As the hybrid battery (traction battery) cannot be charged when the shift
lever is in N, when stopped for long periods of time shift the shift lever to P.
■If “Hybrid Battery Low Hybrid System Stopped Shift to P and Restart” is
shown
Message is displayed when the remainin g charge for the hybrid battery (trac-
tion battery) is low, because vehicle has been shifted N for a long period of
time.
When operating the vehicle, restart the hybrid system.
■If “Shift to P Before Exiting Vehicle” is shown
Message is displayed when the driver’s door is opened without turning the
power switch off with the shift lever in any position other than P.
Shift the shift lever to P.
Other messages displayed on the multi-information display

5517-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
WARNING
■Using the tire jack
Observe the following precautions.
Improper use of the tire jack may cause the vehicle to suddenly fall off the jack, leading
to death or serious injury.
●Do not use the tire jack for any purpose other than replacing tires or installing and
removing tire chains.
●Only use the tire jack that comes with this vehicle for replacing a flat tire.
Do not use it on other vehicles, and do no t use other tire jacks for replacing tires on
this vehicle.
●Put the jack properly in its jack point.
●Do not put any part of your body under the vehicle while it is supported by the jack.
●Do not start the hybrid system or drive the vehicle while the vehicle is supported by
the jack.
●Do not raise the vehicle while someone is inside.
●When raising the vehicle, do not pu t an object on or under the jack.
●Do not raise the vehicle to a height greater than that required to replace the tire.
●Use a jack stand if it is necessary to get under the vehicle.
●When lowering the vehicle, make sure that there is no-one near the vehicle. If there
are people nearby, warn them vocally before lowering.

5617-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U
One of the following may be the cause of the problem:
●The electronic key may not be functioning properly. ( P. 564)
●There may not be sufficient fuel in the vehicle’s tank.
Refuel the vehicle.
●There may be a malfunction in the immobilizer system. ( P. 85)
●There may be a malfunction in the steering lock system.
●The hybrid system may be malfunctioni ng due to an electrical problem such
as electronic key battery depletion or a blown fuse. However, depending on
the type of malfunction, an interim meas ure is available to start the hybrid sys-
tem. ( P. 562)
One of the following may be the cause of the problem:
●The 12-volt battery may be discharged. ( P. 568)
●The 12-volt battery terminal connections may be loose or corroded.
( P. 483)
If the hybrid system will not start
Reasons for the hybrid system not star ting vary depending on the situation.
Check the following and perform the appropriate procedure:
The hybrid system will not start even though the correct starting proce-
dure is being followed. ( P. 232)
The interior lights and headlights are d im, or the horn does not sound or
sounds at a low volume.