coolant temperature LEXUS UX250H 2019 User Guide

3857-2. Steps to take in an emergency
7
When trouble arises
Fluid leaks under the vehicle
(Water dripping from the air condi-
tioning after use is normal.)
 Flat-looking tires or uneven tire
wear
 Engine coolant temperature gauge
needle continually points higher
than normal
 Changes in exhaust sound
 Excessive tire squeal when corner-
ing
 Strange noises related to the sus-
pension system
 Pinging or other noises related to
the hybrid system
 Engine missing, stumbling or run-
ning roughly
 Appreciable loss of power
 Vehicle pulls heavily to one side
when braking 
Vehicle pulls heavily to one side
when driving on a level road
 Loss of brake effectiveness, spongy
feeling, pedal almost touches the
floor
If you think something is
wrong
If you notice any of the following
symptoms, your vehicle probably
needs adjustment or repair. Con-
tact your Lexus dealer as soon as
possible.
Visible symptoms
Audible symptoms
Operational symptoms

3877-2. Steps to take in an emergency
7
When trouble arises
■Malfunction indicator lamp (warning buzzer)
■High coolant temperature warning light* (warning buzzer)
*: This light illuminates on the multi-information display.
■Tire pressure warning light
■Brake system warning light (warning buzzer)
Warning lightDetails/Actions
(U.S.A.)
or
(Canada)
Indicates a malfunction in:
The hybrid system;
 The electronic engine control system; or
 The electronic throttle control system
 Immediately stop the vehicle in a safe place and contact your Lexus
dealer.
Warning lightDetails/Actions
Indicates that the engine coolant temperature is too high
 Immediately stop the vehicle in a safe place.
Handling method ( P.410)
Warning lightDetails/Actions
When the light comes on after bl inking for approximately 1 minute:
Malfunction in the tire pressure warning system
 Have the system checked by your Lexus dealer.
When the light comes on:
Low tire inflation pressure such as
 Natural causes
 Flat tire
 P.393
Warning lightDetails/Actions
(yellow)
Indicates a malfunction in:
The regenerative braking system;
 The electronically controlled brake system; or
 The parking brake system
 Have the vehicle inspected by your Lexus dealer immediately.

4107-2. Steps to take in an emergency
If the engine coolant temperature
gauge enters the red zone or
“Engine Coolant Temp High Stop in
a Safe Place See Owner’s Manual”
is shown on the multi-information
display
1
Stop the vehicle in a safe place and
turn off the air conditioning system,
and then stop the hybrid system.
2
If you see steam:
Carefully lift the hood after the
steam subsides.
If you do not see steam:
Carefully lift the hood.
3
After the hybrid system has cooled
down sufficiently, inspect the hoses
WARNING
■When replacing the 12-volt battery
●When the vent plug is close to the hold
down clamp, the battery fluid (acid)
may leak.
●For information regarding battery
replacement, contact your Lexus
dealer.
●After exchanging, securely attach the
elbow connected to the exhaust hose,
and exhaust hole plug to the exhaust
hole of the exchanged 12-volt battery.
If not properly installed, gases (hydro-
gen) may leak into the vehicle interior,
and there is the possible danger of the
gas igniting and exploding.
NOTICE
■When handling jumper cables
When connecting the jumper cables,
ensure that they do not become entan-
gled in the cooling fans or belt.
■To prevent damaging the vehicle
The exclusive jump starting terminal is to
be used when charging the 12-volt bat-
tery from another vehicle in an emer-
gency. It cannot be used to jump start
another vehicle.
If your vehicle overheats
The following may indicate that
your vehicle is overheating.
 The engine coolant temperature
gauge ( P.78, 82) enters the
red zone, or a loss of hybrid sys-
tem power is experienced. (For
example, the vehicle speed does
not increase.)
 “Engine Coolant Temp High Stop
in a Safe Place See Owner’s
Manual” or “Hybrid system over-
heated Output power reduced” is
shown on the multi-information
display.
 Steam comes out from under the
hood.
Correction procedures

4127-2. Steps to take in an emergency
If “Hybrid system overheated Out-
put power reduced” is shown on the
multi-information display
1
Stop the vehicle in a safe place.
2
Stop the hybrid system and care-
fully lift the hood.
3
After the hybrid system has cooled
down, inspect the hoses and radia-
tor core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “F” and “L” lines on
the reservoir.
Reservoir
“F” line
“L” line 5
Add coolant if necessary.
Water can be used in an emergency if
coolant is unavailable.
6After stopping the hybrid system
and waiting for 5 minutes or more,
start the hybrid system again and
check if “Hybrid system overheated
Output power reduced” is shown
on the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your
Lexus dealer.
If the message is not displayed:
The hybrid system temperature has
dropped and the vehicle may be driven
normally.
However, if the message appears again fre-
quently, contact your Lexus dealer.
A
B
A
B
C
WARNING
■To prevent an accident or injury when
inspecting under the hood of your
vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.

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

4198-1. Specifications
8
Vehicle specifications
0W-20 oil may be used. However, it
must be replaced with SAE 0W-16 at
the next oil change.Outside temperature
Oil viscosity (0W-16 is explained here
as an example):
• The 0W in 0W-16 indicates the characteristic of the oil which allows
cold startability. Oils with a lower
value before the W allow for easier
starting of the engine in cold
weather. • The 16 in 0W-16 indicates the vis-
cosity characteristic of the oil when
the oil is at high temperature. An oil
with a higher viscosity (one with a
higher value) may be better suited if
the vehicle is operated at high
speeds, or under extreme load con-
ditions.
How to read oil container label:
API registered marks is added to some
oil containers to help you select the oil
you should use.
*: The coolant capacity is a reference quantity. If replacement is necessary, contact your Lexus dealer.
A
Cooling system
Capacity*
Gasoline
engine6.2 qt. (5.9 L, 5.2 Imp.qt.)
Power con-
trol unit1.7 qt. (1.6 L, 1.4 Imp.qt.)
Coolant type
Use either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethy lene glycol-based non-
silicate, non-amine, non-nitrite, and non-borate
coolant with long-life hy brid organic acid tech-
nology
Do not use plain water alone.

466Alphabetical Index
Emergency flashers .................................... 378
Energy monitor ................................................97
EngineACC ..................................................................164
Compartment ............................................. 337
Hood................................................................335
How to start the hybrid system ............ 162
Identification number ................................. 417
If your vehicle has to be stopped in an
emergency ................................................ 378
Ignition switch (power switch) .............. 162
Overheating.................................................. 410
Power switch ................................................. 162
Tachometer ............................................ 78, 82
Engine coolant.............................................. 339 Capacity ...........................................................419
Checking ....................................................... 339
Preparing and checking before winter......................................................................... 263
Engine coolant temperature gauge78, 82
Engine oil Capacity .......................................................... 418
Checking ....................................................... 337
Warning light ...............................................386
Engine oil maintenance data .................. 339
EPS (Electric Power Steering) .............. 257 Function .......................................................... 257
Warning light .............................................. 388
EV drive mode................................................165
Event data recorder (EDR) ........................... 8
EV indicator ...................................................... 63
F
Flat tire ............................................................. 399 Tire pressure warning system .............348
Floor mats .......................................................... 24
Fluid Brake.................................................................. 421
Hybrid transmission ................................. 420
Washer ............................................................. 341
Fog lights Replacing light bulbs................................ 374 Switch................................................................ 183
Front passenger occupant classification system .............................................................. 39
Front seats ......................................................... 131 Adjustment ....................................................... 131
Cleaning .........................................................325
Correct driving posture ............................ 25
Driving position memory ........................ 133
Head restraints............................................. 136
Memory recall function............................ 135
Power easy access system .................... 133
Seat heaters ..................................................287
Seat position memory .............................. 133
Seat ventilators ............................................287
Front side marker lights Light switch ..................................................... 177
Front turn signal lights Replacing light bulbs ................................375
Turn signal lever ............................................ 171
Wattage .......................................................... 422
Fuel Capacity ...........................................................417
Fuel gauge ............................................... 78, 82
Information .................................................... 423
Refueling.......................................................... 190
Type ....................................................................417
Warning light .............................................. 390
Fuel consumption Average fuel economy ..............................89
Current fuel consumption ........................89
Fuel filler door ................................................ 190 Refueling.......................................................... 190
When the fuel filler door cannot be
opened.........................................................402
Fuel gauge ................................................. 78, 82
Fuses ................................................................. 370
G
Garage door opener .................................... 311
Gauges ....................................................... 78, 82
G-force............................................................... 90
Glove box ....................................................... 294

474Alphabetical Index
Engine ............................................................. 387
High coolant temperature .................... 387
Hybrid system overheat......................... 392
Hybrid system ............................................. 387
Intuitive parking assist................. 238, 389
Low engine oil pressure.........................386
LTA (Lane Tracing Assist)......... 205, 391
Open door.............................................. 109, 111
Open hood........................................................ 111
Open window ...............................................146
PKSA (Parking Support Alert) ............. 231
PKSB (Parking Support Brake) .........390
Pre-collision braking................................. 198
RCTA (Rear Cross Traffic Alert) ......389
Seat belt ............................................... 390, 391
Warning lights............................................... 386 ABS ................................................................. 388
Brake hold operated indicator ...........389
Brake Override System ...........................391
Brake system ...............................................386
Charging system .......................................386
Drive-Start Control ....................................391
Electric power steering ......................... 388
High coolant temperature .................... 387
Intuitive parking assist OFF indicator.........................................................................389
Low engine oil pressure.........................386
Low fuel level ...............................................390
LTA indicator .................................................391
Malfunction indicator lamp................... 387
Parking brake indicator ..........................389
PKSB OFF indicator ................................390
Pre-collision system ................................. 392
RCTA OFF indicator...............................389
Seat belt reminder light ............... 390, 391
Slip indicator ............................................... 388
SRS................................................................... 388
Tire pressure ................................................ 387
Warning messages ..................................... 395
Washer Checking ......................................................... 341
Preparing and checking before winter ..........................................................................263
Switch..................................................... 184, 188
Washing and waxing.................................. 322
Weights Cargo capacity .............................................157
Load limits ...................................................... 160
Weights ........................................................... 416
Wheels ............................................................. 363 Size .................................................................... 422
Window glasses .............................................145
Window lock switch .....................................146
Windows Power windows ........................................... 145
Rear window defogger........................... 277
Washer ................................................. 184, 188
Windshield wiper de-icer ..........................281
Windshield wipers Intermittent windshield wipers ............. 184
Position............................................................. 186
Rain-sensing windshield wipers .......... 184
Winter driving tips....................................... 263
Wireless remote control key ................... 106 Battery-saving function............................ 125
Locking/Unlocking ................................... 106
Panic mode .................................................... 106
Replacing the battery .............................. 368
For information regarding the equipment listed below, refer to
the “NAVIGATION AND MULTI-
MEDIA SYSTEM OWNER’S
MANUAL”.
· Audio/video system
· Navigation system
· Lexus parking assist monitor
· Lexus Enform