snow LEXUS UX250H 2019 Service Manual

3486-3. Do-it-yourself maintenance
■Run-flat tires
●The run-flat tires are for only this vehicle.
Do not use the tires on other vehicles.
●Do not mix run-flat tires and normal tires.
●If non-genuine Lexus wheels are used, it
may be impossible to sufficiently demon-
strate the performance of run-flat tires.
Your vehicle is equipped with a tire
pressure warning system that uses tire
pressure warning valves and transmit-
ters to detect low tire inflation pressure
before serious problems arise.
If the tire pressure drops below a
predetermined level, the driver is
warned by a screen display and a
warning light. ( P.387, 395)
 The tire pressure detected by the
tire pressure warning system can be
displayed on the multi-information
display. ( P.87)
The illustration used is intended as an
example, and may differ from the image
that is actually displayed on the multi-infor-
mation display.
■Routine tire inflation pressure checks
The tire pressure warning system does not
replace routine tire inflation pressure
checks. Make sure to check tire inflation pressure as part of your routine of daily
vehicle checks.
■Tire inflation pressure
●It may take a few minutes to display the
tire inflation pressu
re after the power
switch is turned to ON. It may also take a
few minutes to display the tire inflation
pressure after inflatio n pressure has been
adjusted.
●Tire inflation pressure changes with tem-
perature. The displaye d values may also
be different from the values measured
using a tire pressure gauge.
■Situations in which the tire pressure
warning system may not operate prop-
erly
●In the following cases, the tire pressure
warning system may not operate prop-
erly.
• 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.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects the 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 extremely higher than the specified level.
• If wheels without tire pressure warning
valves and transmitters are used.
• If the ID code on the tire pressure warn- ing valves and transmitters is not regis-
tered in the tire pressure warning
computer.
●Performance may be af fected in the fol-
lowing situations.
• Near a TV tower, electric power plant,
gas station, radio stat ion, large display,
airport or other fac ility that generates
strong 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 correctly
displayed due to the radio wave conditions,
Tire pressure warning system

4137-2. Steps to take in an emergency
7
When trouble arises
1Stop the hybrid system. Shift the
shift lever to P and set the parking
brake.
2
Remove the mud, snow or sand
from around the front wheels.
3
Place wood, stones or some other
material under the front wheels to
help provide traction.
4
Restart the hybrid system.
5
Shift the shift lever to D or R and
release the parking brake. Then,
while exercising caution, depress
the accelerator pedal.
■When it is difficult to free the vehicle
Press the switch to turn off TRAC.
(  P.257)
WARNING
●After the hybrid system has been
turned off, check that the “READY”
indicator is off. When the hybrid sys-
tem is operating, the gasoline engine
may automatically start, or the cooling
fan may suddenly operate even if the
gasoline engine stops. Do not touch or
approach rotating parts such as the
fan, which may lead to fingers or cloth-
ing (especially a tie, a scarf or a muf-
fler) getting caught, resulting in serious
injury.
●Do not loosen the coolant reservoir
cap while the hybrid system and radia-
tor are hot.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine/power control
unit coolant
Add coolant slowly after the hybrid sys-
tem has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too
quickly can cause damage to the hybrid
system.
■To prevent damage to the cooling sys-
tem
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust
etc.).
●Do not use any coolant additive.
If the vehicle becomes stuck
Carry out the following proce-
dures if the tires spin or the vehicle
becomes stuck in mud, dirt or snow:
Recovering procedure

4328-1. Specifications
*:Table 1  Occupant loading and distribution for vehicle normal load for various desig-
nated seating capacities
Pneumatic tire
A mechanical device made of rubber, chemicals, fabric and
steel or other materials, that, when mounted on an automo-
tive wheel, provides the traction and contains the gas or fluid
that sustains the load
Radial ply tire
A pneumatic tire in which the ply cords that extend to the
beads are laid at substantiall y 90 degrees to the centerline
of the tread
Reinforced tireA tire designed to operate at higher loads and at higher
inflation pressures than the corresponding standard tire
Section width
The linear distance between the exteriors of the sidewalls of
an inflated tire, excluding elevations due to labeling, decora-
tion, or protective bands
SidewallThat portion of a tire between the tread and bead
Sidewall separationThe parting of the rubber comp ound from the cord material
in the sidewall
Snow tire
A tire that attains a traction index equal to or greater than
110, compared to the ASTM E-1136 Standard Reference
Test Tire, when using the snow traction test as described in
ASTM F-1805-00, Standard Test Method for Single Wheel
Driving Traction in a Straight Line on Snow-and Ice-Cov-
ered Surfaces, and which is ma rked with an Alpine Symbol
( ) on at least one sidewall
Test rimThe rim on which a tire is fitt ed for testing, and may be any
rim listed as appropriate for use with that tire
TreadThat portion of a tire that comes into contact with the road
Tread ribA tread section running circ umferentially around a tire
Tread separationPulling away of the tread from the tire carcass
Treadwear indicators (TWI)The projections within the principal grooves designed to
give a visual indication of the degrees of wear of the tread
Wheel-holding fixtureThe fixture used to hold the wheel and tire assembly
securely during testing
Tire related termMeaning

462What to do if... (Troubleshooting)
possible to have the tire replaced.
( P.355)
 Try the procedure for when the vehi-
cle becomes stuck in mud, dirt, or
snow. ( P.413)
The vehicle becomes stuck

Alphabetical Index471
Rev indicator .................................................... 84
Rev peak............................................................. 84
Road Sign Assist ............................................ 214
RSA (Road Sign Assist) .............................. 214
Run-flat tires........................................ 347, 399
S
Seat belt reminder light................... 390, 391
Seat belts............................................................ 26 Adjusting the seat belt shoulder anchor height............................................................... 29
Automatic Locking Retractor ................ 28
Child restraint system installation ......... 44
Cleaning and maintaining the seat belt ......................................................................... 325
Emergency Locking Retractor .............. 28
How to wear your seat belt ......................27
How your child should wear the seat belt ............................................................................ 28
Pregnant women, proper seat belt use .............................................................................27
Reminder light and buzzer ........ 390, 391
Seat belt extender ........................................ 28
Seat belt pretensioners .............................. 29
SRS warning light ..................................... 388
Seat heaters .................... ............................... 286
Seating capacity............................................ 160
Seat position memory..................................133
Seats........................................................... 131, 132 Adjustment precautions ............................ 131
Adjustment....................................................... 131
Child seats/child restraint system installa-tion .................................................................... 44
Cleaning......................................................... 325
Driving position memory.........................133
Head restraint................................................136
Power easy access system .....................133
Properly sitting in the seat ........................ 25
Seat heaters .................................................. 287
Seat position memory ...............................133
Seat ventilators............................................ 287
Seat ventilators ............................................. 286 Secondary Collision Brake ..................... 257
Sensor
Automatic headlight system ................... 177
Automatic High Beam system .............180
Inside rear view mirror ............................... 141
Intuitive parking assist .............................. 232
LTA (Lane Tracing Assist) ................... 205
Parking Support Brake function (rear-crossing vehicles)................................... 252
Parking Support Brake function (static objects) ........................................................248
Radar sensor ...................................... 192, 227
Rain-sensing windshield wipers .......... 186
RCTA...............................................................240
Service plug ...................................................... 65
Service reminder message ..................... 328
Shift lever Hybrid transmission................................... 168
Side airbags ........................................................31
Side doors........................................................ 108
Side marker lights Light switch ..................................................... 177
Side mirrors ..................................................... 142 Adjustment ......................................................142
BSM (Blind Spot Monitor).................... 226
Folding...............................................................143
Linked mirror functi on when reversing
............................................................................143
Mirror position memory .......................... 133
RCTA function ............................................239
Side turn signal lights Replacing light bulbs ................................ 374
Turn signal lever ............................................ 171
Side windows ..................................................145
Smart access system with push-button start................................................................... 124Antenna location ..........................................124
Entry functions ..................................... 108, 113
Starting the hybrid system .......................162
Snow tires ....................................................... 263
Spark plug ...................................................... 420
Specifications ..................................................416

Alphabetical Index473
Tire inflation pressure display function
.........................................................................348
Warning light ............................................... 387
Tire information ............................................ 425 Glossary......................................................... 429
Size.................................................................... 426
Tire identification number ..................... 426
Uniform Tire Quality Grading............ 427
Tire pressure warning system Function ..........................................................348
Initializing .........................................................351
Installing tire pressure warning valves and transmitters ..................................... 350
Registering ID codes ............................... 352
Warning light ............................................... 387
Tires................................................................... 345 Chains ............................................................. 264
Checking ....................................................... 345
If you have a flat tire ..................................399
Inflation pressure..........................................361
Information .................................................... 425
Replacing .......................................................355
Rotating tires ................................................ 347
Run-flat tires ..................................... 347, 399
Size.................................................................... 422
Snow tires ...................................................... 263
Tire pressure warning system .............348
Warning light ............................................... 387
Tools.......................................................296, 355
Top tether strap............................................... 54
Total load capacity ........................................416
Towing Dinghy towing ................................................ 161
Emergency towing .................................... 381
Towing eyelet ..............................................384
Trailer towing ................................................ 160
TRAC (Traction Control) ........................ 257
Traction battery (hybrid battery) ............. 65 Hybrid battery (traction battery) air vents............................................................................ 67
Location............................................................. 65
Specification .................................................. 418 Warning message ........................................68
Traction Control (TRAC) ........................ 257
Traction motor (electric motor) ............... 62
Trailer towing ................................................. 160
Transmission Hybrid transmission....................................167
Paddle shift switches .......................169, 170
S mode ............................................................. 170
Selecting the driving mode ...................255
Trip meters ............................................... 80, 86
Turn signal lights Replacing light bulbs ................................ 374
Turn signal lever ............................................ 171
Wattage .......................................................... 422
U
USB charging ports.................................... 302
V
Vanity lights..................................................... 301Wattage .......................................................... 422
Vanity mirrors ................................................ 301
Vehicle data recording ....................................7
Vehicle identification number ..................416
Vehicle Stability Cont rol (VSC) ........... 256
Ventilators (seat ventilators)................... 286
VSC (Vehicle Stability Control) ........... 256
W
Warning buzzers ABS .................................................................. 388
Airbags........................................................... 388
Approach warning.................................... 222
Brake hold .................................................... 389
Brake Override System .......................... 391
Brake system............................................... 386
Charging system....................................... 386
Downshifting ................................................... 171
Drive-Start Control.................................... 391
Electric power steering.......................... 388