2018 LEXUS RX450h warning

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.

666 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UWARNING ■
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 ha s 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 si gnificantly 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 th e driver’s responsibility to ma intain correct tire pressure,
even if under-inflation has not reached the le vel to trigger illumina tion 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 vehicl e start-ups as long as the
malfunction exists. When the malfunction in dicator is illuminated, the system may not
be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfun ctions 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 pressu re warning system) to continue to function
properly.
NOTICE ■
To ensure the tire pressure warning system operates properly
Do not install tires with different specificatio ns or makers, as the tire pressure warning
system may not operate properly.

6678-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UThe warning lights and warning buzzers operate as follows depending on the
content of the message. If a message indicates the need for inspection by a
dealer, have the vehicle inspected by your Lexus dealer immediately.If a warning message is displayed The multi-information display shows warn ings of system malfunctions, incor-
rectly performed operations, and messag es that indicate a need for mainte-
nance. When a message is shown, perform the correction procedure
appropriate to the message. 
Except F SPORT models 
F SPORT models
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 messages are sh own again after the appropriate actions
have been performed, contact your Lexus dealer.
Messages and warnings 1
2
System
warning
light Warning buzzer
* Warning
Comes
on ⎯ Sounds Indicates an important situation, such
as when a system related to driving is
malfunctioning or that danger may
result if the correction procedure is not
performed
⎯ Comes on
or flashes Sounds Indicates an important situation, such
as when the systems shown on the
multi-information display may be mal-
functioning

668 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U* : A buzzer sounds the first time a message is shown on the multi-information display.
●
If the following messages are shown, there may be a malfunction.
Immediately stop the vehicle in a safe place and contact your Lexus dealer.
Continuing to drive the vehicle may be dangerous.
• “Braking Power Low Stop in a Safe Place See Owner’s Manual”
• “Oil Pressure Low Stop in a Safe Place See Owner’s Manual”
• “Charging System Malfunction See Owner’s Manual” ●
If the following messages are shown, there may be a malfunction.
Immediately have the vehicle inspected by your Lexus dealer.
• “Hybrid System Malfunction”
•“Check Engine”
• “Hybrid Battery System Malfunction”
• “Accelerator System Malfunction”
• “Access System with Elec. Key Malfunction See Owner’s Manual” ●
If “Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
displayed, following the instructions, accordingly. ( → P. 702)Flashes ⎯ Sounds Indicates a situation, such as when
damage to the vehicle or danger may
result
Comes
on ⎯ Does not sound Indicates a condition, such as malfunc-
tion of electrical components, their
condition, or indicates the need for
maintenance
Flashes ⎯ Does not sound Indicates a situation, such as when an
operation has been performed incor-
rectly, or indicates how to perform an
operation correctly
If a message instructing to refer to the Owner’s Manual is displayed System
warning
light Warning buzzer
* Warning

672 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
If “Maintenance Required Visit Your Dealer” is displayed (U.S.A. only)
Indicates that all maintenance is requir ed to correspond to the driven distance
on the maintenance schedule
* .
Comes on approximately 5000 miles (8000 km) after the message has
been reset.
(The indicator will not work properly unless the message has been reset.)
Perform the necessary maintenance. Please reset the message after the main-
tenance is performed. ( → P. 588)
* : Refer to the separate “Scheduled Mainte nance” or “Owner’s Manual Supplement”
for the maintenance interval applicable to your vehicle. ■
System warning lights
The master warning light does not come on or flash in the following cases. Instead, a sep-
arate system warning light will come on along with a message shown on the multi-infor-
mation display. ●
“Braking Power Low Visit Your Dealer”:
The brake system warning light (yellow) come on. ( → P. 660)●
“Antilock Brake System Malfunction Visit Your Dealer”:
The ABS warning light comes on. ( → P. 661)●
“Charging System Malfunction See Ow ner's Manual” (F SPORT models):
The charging system wa rning light comes on. ( → P. 660)■
Warning buzzer
→ P. 665
NOTICE ■
“High Power Consumption Partial Limit On AC/Heater Operation” is frequently
shown
There is a possible malfunction relating to the charging system or the 12-volt battery
may be deteriorating. Have the vehicle inspected by your Lexus dealer.

6738-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85U●
Stop the vehicle in a safe pl ace on a hard, flat surface.●
Set the parking brake. ●
Shift the shift lever to P. ●
Stop the hybrid system. ●
Turn on the emergency flashers. ( → P. 652)If you have a flat tire Your vehicle is equipped with a spare tire. The flat tire can be replaced with
the spare tire.
For details about tires: → P. 611WARNING ■
If you have a flat tire
Do not continue driving with a flat tire.
Driving even a short distance with a flat ti re can damage the tire and the wheel beyond
repair, which could re sult in an accident.
Before jacking up the vehicle

676 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UWARNING ■
Using the tire jack
Observe the following precautions.
Improper use of the tire jack may cause the ve hicle to suddenly fall off the jack, leading
to death or serious injury. ●
Do not use the tire jack for any purpose ot her 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 th e 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.

680 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85UPull out the spare tire and stand it
against the bumper.
Fully depress the secondary latch
and remove the holding bracket
from the hoist assembly .
Tilt the bracket and pass it
through the wheel opening. Then
remove the hoist assembly . 6
7
A
B C
8
B
C
WARNING ■
When storing the spare tire
Be careful not to catch fingers or other body parts between the spare tire and the body
of the vehicle.