fuel LEXUS UX250H 2019 Service Manual

3316-2. Maintenance
6
Maintenance and care
The OBD system determines that a
problem exists somewhere in the emis-
sion control system. Your vehicle may
not pass the I/M test and may need to
be repaired. Contact your Lexus
dealer to service the vehicle.
When the 12-volt battery is discon-
nected or discharged
Readiness codes that are set during
ordinary driving are erased.
Also, depending on your driving
habits, the readiness codes may not
be completely set.
 When the fuel tank cap is loose
The malfunction indicator lamp
comes on indicating a temporary
malfunction and your vehicle may
not pass the I/M test.
Fluid leaks
• There should not be any
signs of fluid leakage
after the vehicle has
been parked.
Tires
• Is the tire inflation pres-sure correct?
• The tires should not be damaged or excessively
worn.
• Have the tires been rotated according to the
maintenance schedule?
• The wheel nuts should not be loose.
Windshield
wipers/
rear window
wiper
•The wiper blades should not show any signs of
cracking, splitting, wear,
contamination or defor-
mation.
•The wiper blades should clear the wind-
shield/rear window with-
out streaking or
skipping.
ItemsCheck pointsEmission inspection and
maintenance (I/M) pro-
grams
Some states have vehicle emission
inspection programs which include
OBD (On Board Diagnostics)
checks. The OBD system monitors
the operation of the emission con-
trol system.
If the malfunction indicator lamp
comes on
Your vehicle may not pass the
I/M test in the following situa-
tions:

3346-3. Do-it-yourself maintenance
Tire inflation
pressure
( P.361)• Tire pressure gauge
• Compressed air source
Washer fluid
( P.341)
• Water or washer fluid
containing antifreeze
(for winter use)
• Funnel (used only for adding water or washer
fluid)
WARNING
The engine compartment contains many
mechanisms and fluids that may move
suddenly, become hot, or become elec-
trically energized. To avoid death or seri-
ous injury, observe the following
precautions.
■When working on the engine com-
partment
●Make sure that “IGNITION ON” on
the multi-information display and the
“READY” indicator are both off.
●Keep hands, clothi ng and tools away
from the moving fan and engine drive
belt.
●Be careful not to touch the engine,
power control unit, radiator, exhaust
manifold, etc. right after driving as they
may be hot. Oil and other fluids may
also be hot.
●Do not leave anything that may burn
easily, such as paper and rags, in the
engine compartment.
●Do not smoke, cause sparks or expose
an open flame to fuel. Fuel fumes are
flammable.
■When working near the electric cool-
ing fans or radiator grille
Be sure the power switch is OFF.
With power switch in ON, the electric
cooling fans may automatically start to
run if the air conditioning is on and/or the
coolant temperature is high. ( P.340)
ItemsParts and tools■Safety glasses
Wear safety glasses to prevent flying or
falling material, fluid spray, etc. from get-
ting in your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter
removed may cause excessive engine
wear due to dirt in the air.

3616-3. Do-it-yourself maintenance
6
Maintenance and care
The recommended cold tire inflation
pressure and tire size are displayed on
the tire and loading information label.
( P.422)
Tire valve Tire pressure gauge
1 Remove the tire valve cap.
2 Press the tip of the tire pressure
gauge onto the tire valve.
3 Read the pressure using the gauge
gradations.
4 If the tire inflation pressure is not at
the recommended level, adjust the
pressure.
If you add too much air, press the
center of the valve to deflate.
5 After completing the tire inflation
pressure measurement and adjust-
ment, apply soapy water to the
valve and check for leakage.
6 Put the tire valve cap back on.
■Tire inflation pressure check interval
You should check tire inflation pressure
every two weeks, or at least once a month.
Do not forget to check the spare.
■Effects of incorrect tire inflation pres-
sure
Driving with incorrect ti re inflation pressure
may result in the following:
●Reduced fuel economy
●Reduced driving comfort and poor han-
dling
●Reduced tire life due to wear
●Reduced safety
●Damage to the drive train
If a tire needs frequent inflating, have it
checked by your Lexus dealer.
■Instructions for checking tire inflation
pressure
When checking tire inflation pressure,
observe the following:
●Check only when the tires are cold.
If your vehicle has been parked for at
least 3 hours or has not been driven for
Tire inflation pressure
Checking the specified tire infla-
tion pressure
Inspection and adjustment pro-
cedure
A
B

3656-3. Do-it-yourself maintenance
6
Maintenance and care
filter.
Remove the dust from the air intake
vent with a vacuum cleaner etc.
Make sure to only use a vacuum to suck
out dust and clogs. Attempting to blow out
dust and clogs using an airgun etc. may
push it into the air intake vent.
If dust and clogs cannot be completely
removed with the air intake vent cover
installed, remove the cover and clean
NOTICE
■When using the air conditioning sys-
tem
Make sure that a filter is always installed.
Using the air conditioning system without
a filter may cause damage to the system.
■To prevent damage to the filter cover
When moving the filter cover in the
direction of arrow to release the fitting,
pay attention not to apply excessive force
to the claws. Otherwise, the claws may
be damaged.
Cleaning the hybrid battery
(
traction battery) air intake
v
ent and filter
To prevent the fuel economy from
being affected, visually inspect the
hybrid battery (traction battery) air
intake vent periodically for dust and
clogs. If it is dusty or clogged or if
“Maintenance required for Traction
battery cooling parts See owner’s
manual” is shown on the multi-infor-
mation display, clean the air intake
vent using the following proce-
dures:
Cleaning the air intake vent
If dust and clogs cannot be com-
pletely removed

3676-3. Do-it-yourself maintenance
6
Maintenance and care
7Install the air intake vent cover.
1
Insert the tab of the cover as shown
in the illustration.
2
Push the cover to engage the 5
claws.
8
Using a Phillips screwdriver, install
the clip.
■Scheduled maintenance of the air
intake vent is necessary when
In some situations such as when the vehicle
is used frequently or in heavy traffic or dusty
areas, the air intake vent may need to be
cleaned more regularly. For details, refer to
the “Warranty and Service Guide”,
“Owner’s Manual Supplement” or “Sched-
uled Maintenance”.
■Cleaning the air intake vent
●Dust in the air intake vent may interfere
with the cooling of the hybrid battery
(traction battery). If charging/discharging
of the hybrid battery (traction battery)
becomes limited, the distance that the
vehicle can be driven using the electric
motor (traction motor) may be reduced
and the fuel economy may be reduced. Inspect and clean the air intake vent peri-
odically.
●Improper handling of the air intake vent
cover and filter may result in damage to
them. If you have any concerns about
cleaning the filter, contact your Lexus
dealer.
■If “Maintenance required for Traction
battery cooling parts See owner’s man-
ual” is shown on the multi-information
display
●If this warning message is shown on the
multi-information display, remove the air
intake vent cover and clean the filter.
(
 P.365)
●After cleaning the air intake vent, start
the hybrid system and check that the
warning message is no longer shown. It
may take approximately 20 minutes after
the hybrid system is started until the
warning message disappears. If the warn-
ing message does not disappear, have the
vehicle inspected by your Lexus dealer.
WARNING
■When cleaning the air intake vent
●Do not use water or other liquids to
clean the air intake vent. If water is
applied to the hybrid battery (traction
battery) or other components, a mal-
function or fire may occur.
●Before cleaning the air intake vent,
make sure to turn the power switch off
to stop the hybrid system.
■When removing the air intake vent
cover
Do not touch the service plug located
near the air intake vent. ( P.66)

377
7
7
When trouble arises
When trouble arises
7-1. Essential informationEmergency flashers.................. 378
If your vehicle has to be stopped in an emergency .......................... 378
If the vehicle is trapped in rising water............................................ 379
7-2. Steps to take in an emergency If your vehicle needs to be towed......................................................... 381
If you think something is wrong ........................................................ 385
If a warning light turns on or a warning buzzer sounds ....... 386
If a warning message is displayed ........................................................ 395
If you have a flat tire.................. 399
If the hybrid system will not start ........................................................ 400
If you lose your keys ................. 402
If the fuel filler door cannot be opened........................................ 402
If the electronic key does not operate properly .................... 403
If the 12-volt battery is discharged ........................................................ 405
If your vehicle overheats ......... 410
If the vehicle becomes stuck . 413

3907-2. Steps to take in an emergency
■PKSB OFF indicator (warning buzzer)
■Low fuel level warning light
■Driver’s and front passenger’s seat belt reminder light (warning buzzer)*
*: Driver’s seat belt warning buzzer:
The driver’s seat belt warning buzzer sounds to al ert the driver that his or her seat belt is not
fastened. Once the power switch is turned to ON, 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 after 24 seco nds, the buzzer will sound intermitte ntly for 6 seconds. Then, if the
seat belt is still unfastened, the buzzer will sound in a different tone for 90 more seconds.
Front passenger’s seat belt warning buzzer:
The front passenger’s seat belt warning buzzer sounds to alert the front passenger that his
or her seat belt is not fastened. The 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 6 seconds. Th en, if the seat belt is still unfastened, the buzzer will sound in
a different tone for 90 more seconds.
Warning lightDetails/Actions
(flashes)
When a buzzer sounds:
Indicates a malfunction in the PK SB (Parking Support Brake) 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.
 Follow the instructions displayed on the multi-information display.
(  P.246)
Warning lightDetails/Actions
Indicates that remaining fuel is approx imately 1.6 gal. (6.0L, 1.3 Imp.gal.)
or less
 Refuel the vehicle.
Warning lightDetails/Actions
Warns the driver and/or front passe nger 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.

3947-2. Steps to take in an emergency
WARNING
●If the tire pressure warning light comes
on even after tire inflation pressure
adjustment, it is probable that you have
a flat tire. Have the flat tire replaced by
the nearest Lexus dealer.
●Avoid abrupt maneuvering and brak-
ing.
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.
■Maintenance of the tires
Each tire, including the spare (if pro-
vided), should be checked monthly when
cold and inflated to the inflation pressure
recommended by the vehicle manufac-
turer on the vehicle placard or tire infla-
tion pressure label (tire and load
information label). (If your vehicle has
tires of a different size than the size indi-
cated on the vehicle placard or tire infla-
tion pressure label [tire and load
information label], yo u should determine
the proper tire infl ation pressure for
those tires.)
As an added safety feature, your vehicle
has been equipped with a tire pressure
monitoring system (TPMS-tire pressure
warning system) that illuminates a low
tire pressure telltale (tire pressure warn-
ing light) when one or more of your tires
is significantly under-inflated. Accord-
ingly, when the low tire pressure telltale
(tire pressure warnin g light) illuminates,
you should stop and check your tires as
soon as possible, and inflate them to the
proper pressure. Driving on a signifi-
cantly under-inflated tire causes the tire
to overheat and can lead to tire failure.
Under-inflation also reduces fuel effi-
ciency and tire tread life, and may affect
the vehicle’s handling and stopping abil-
ity.
Please note that the TPMS (tire pressure
warning 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 level to trigger illumina-
tion of the TPMS low tire pressure telltale
(tire pressure warning light).
Your vehicle has also been equipped with
a TPMS (tire pressure warning system)
malfunction indicator to indicate when
the system is not operating properly. The
TPMS (tire pressure warning system)
malfunction indicator is combined with
the low tire pressure telltale (tire pres-
sure warning light) . When the system
detects a malfunction, the telltale will
flash for approximately one minute and
then remain continuously illuminated.
This sequence will continue upon subse-
quent 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 func-
tioning 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 specifi-
cations or makers, as the tire pressure
warning system may not operate prop-
erly.

4007-2. Steps to take in an emergency
One of the following may be the cause
of the problem:
The electronic key may not be func-
tioning properly. ( P.403)
 There may not be sufficient fuel in
the vehicle’s tank.
Refuel the vehicle. ( P.190)
 There may be a malfunction in the
immobilizer system. ( P.69)
 There may be a malfunction in the
steering lock system.
 The hybrid system may be malfunc-
tioning due to an electrical problem
such as electronic key battery
depletion or a blown fuse. However,
depending on the type of malfunc-
tion, an interim measure is available
to start the hybrid system.
One of the following may be the cause
NOTICE
■When replacing the tires
When removing or fitting the wheels,
tires or the tire pressure warning valve
and transmitter, contact your Lexus
dealer as the tire pr essure warning valve
and transmitter may be damaged if not
handled correctly.
■When driving over bumps
If a vehicle has a flat tire, the vehicle
height will be lower than usual. Ensure
that nothing strikes the bottom of the
vehicle.
■To avoid damaging the tire pressure
warning valves and transmitters
When a tire is repaired with liquid seal-
ants, the tire pressure warning valve and
transmitter may not operate properly. If a
liquid sealant is used , contact your Lexus
dealer or other qualified service shop as
soon as possible. Make sure to replace
the tire pressure warning valve and trans-
mitter when replacing the tire. ( P.350)
If the hybrid system will not
s
tart
Reasons for the hybrid system not
starting vary depending on the situ-
ation. Check the following and per-
form the appropriate procedure:
The hybrid system will not start
even though the correct starting
procedure is being followed.
(  P.162)
The interior lights and head-
lights are dim, or the horn does
not sound or sounds at a low vol-
ume.

4027-2. Steps to take in an emergency
1Remove the cover inside the lug-
gage compartment by inserting a
screwdriver.
When removing the cover, to prevent dam-
age, cover the tip of the screwdriver with a
rag.
2Pull the lever.
Using the lever to open the fuel filler
door may not allow for an adequate
If you lose your keys
New genuine mechanical keys can
be made by your Lexus dealer using
another mechanical key and the
key number stamped on your key
number plate. Keep the plate in a
safe place such as your wallet, not in
the vehicle.
NOTICE
■When an electronic key is lost
If the electronic key remains lost, the risk
of vehicle theft increases significantly.
Visit your Lexus deal er immediately with
all remaining electronic keys and the
card key (if equipped) that were pro-
vided with your vehicle.
If the fuel filler door cannot
b
e opened
If the fuel filler door opener switch
cannot be operated, contact your
Lexus dealer to service the vehicle.
In case where refueling is urgently
necessary, the following procedure
can be used to open the fuel filler
door.
Opening the fuel filler door