engine coolant LEXUS UX250H 2019 User Guide

3376-3. Do-it-yourself maintenance
6
Maintenance and care
Fuse boxes (P.370)
Engine coolant reservoir ( P.339)
Engine oil filler cap ( P.338)
Power control unit coolant reservoir ( P.340)
Brake fluid reservoir ( P.341)
Radiator ( P.340)
Condenser ( P.340)
Electric cooling fans
Engine oil level dipstick ( P.337)
Washer fluid tank ( P.341)
■12-volt battery
 P.342
With the engine at operating tempera-
ture and turned off, check the oil level
Engine compartment
Components
A
B
C
D
E
F
G
H
I
J
Checking and adding the engine
oil

3396-3. Do-it-yourself maintenance
6
Maintenance and care
after replacing the engine
●If low quality oil or oil of an inappropriate
viscosity is used
●When driving at high engine speeds or
with a heavy load, when towing, or when
driving while accelera ting or decelerat-
ing frequently
●When leaving the engine idling for a long
time, or when driving frequently through
heavy traffic
■After changing the engine oil
The engine oil maintenance data should be
reset. Perform the following procedures:
1
Press or of the meter control
switches and select .
2
Press or of the meter control
switches, select “Vehicle Settings” and
then press “OK”.
3
Press or of the meter control
switches, select “Oil Maintenance” and
then press and hold “OK”.
4
Select “Yes” and press “OK”.
“Reset Complete” will be displayed when
the reset procedure has been completed.
The coolant level is satisfactory if it is
between the “FULL/F” and “LOW/L”
lines on the reservoir when the hybrid
system is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line,
add coolant up to the “FULL” line.
(  P.410)
WARNING
■Used engine oil
●Used engine oil contains potentially
harmful contaminants which may
cause skin disorders such as inflamma-
tion and skin cancer, so care should be
taken to avoid prolonged and
repeated contact. To remove used
engine oil from your skin, wash thor-
oughly with soap and water.
●Dispose of used oil and filters only in a
safe and acceptable manner. Do not
dispose of used oil and filters in house-
hold trash, in sewers or onto the
ground. Call your Lexus dealer, ser-
vice station or auto parts store for
information concerning recycling or
disposal.
●Do not leave used engine oil within the
reach of children.
NOTICE
■To prevent serious engine damage
Check the oil level on a regular basis.
■When replacing the engine oil
●Be careful not to spill engine oil on the
vehicle components.
●Avoid overfilling, or the engine could
be damaged.
●Check the oil level on the dipstick
every time you refill the vehicle.
●Be sure the engine o il filler cap is prop-
erly tightened.
Checking the coolant
A
B
C

3406-3. Do-it-yourself maintenance
■Power control unit coolant reser-
voirReservoir cap
“F” line
“L” line
If the level is on or below the “L” line, add
coolant up to the “F” line.
■Coolant selection
Only use “Toyota Super Long Life Coolant”
or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite,
and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mix-
ture of 50% coolant and 50% deionized
water.
(Minimum temperature: -31°F [-35°C])
Canada:
“Toyota Super Long Life Coolant” is a mix-
ture of 55% coolant and 45% deionized
water.
(Minimum temperature: -44°F [-42°C])
For more details about coolant, contact
your Lexus dealer.
■If the coolant level drops within a short
time of replenishing
Visually check the radiator, hoses,
engine/power control unit coolant reservoir
caps, drain cock and water pump.
If you cannot find a leak, have your Lexus
dealer test the cap and check for leaks in
the cooling system.
Check the radiator and condenser and
clear away any foreign objects.
If either of the above parts is extremely
dirty or you are not sure of their condi-
tion, have your vehicle inspected by
your Lexus dealer.
A
B
C
WARNING
■When the hybrid system is hot
Do not remove the en gine/power control
unit coolant reservoir caps.
The cooling system may be under pres-
sure and may spray hot coolant if the cap
is removed, causing serious injuries, such
as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor
straight antifreeze. The correct mixture
of water and antifreeze must be used to
provide proper lubrication, corrosion
protection and cooling. Be sure to read
the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to pre-
vent it from damaging parts or paint.
Checking the radiator and con-
denser
WARNING
■When the hybrid system is hot
Do not touch the radiator or condenser
as they may be hot and cause serious
injuries, such as burns.

3416-3. Do-it-yourself maintenance
6
Maintenance and care
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■Adding fluid
Make sure to check the fluid type and
prepare the necessary item.
 Fluid type
FMVSS No.116 DOT 3 or SAE J1703
brake fluid
FMVSS No.116 DOT 4 or SAE J1704
brake fluid
Items
Clean funnel
■Brake fluid can absorb moisture from
the air
Excess moisture in the brake fluid can cause
a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
If none of the washer do not work or
the “Windshield Washer Fluid Low”
appears on the multi-information dis-
play, the washer tank may be empty.
Add washer fluid.
WARNING
■When the electric cooling fans are
operating
Do not touch the engine compartment.
With the power switch in ON, the elec-
tric cooling fans may automatically start
to run if the air conditioning is on and/or
the coolant temperature is high. Be sure
the power switch is OFF when working
near the electric cooling fans or radiator
grille.
Checking and adding the brake
fluid
WARNING
■When filling the reservoir
Take care as brake fluid can harm your
hands and eyes and damage painted sur-
faces.
If fluid gets on your hands or in your eyes,
flush the affected area with clean water
immediately.
If you still experience discomfort, see a
doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go
down slightly as the brake pads wear out
or when the fluid leve l in the accumulator
is high.
If the reservoir need s frequent refilling,
there may be a serious problem.
Adding the washer fluid

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.

3987-2. Steps to take in an emergency
reset. If necessary, perform maintenance.
Please reset the message after the mainte-
nance is performed. (P.328)
*: Refer to the separa te “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.
■If “Maintenance Required Visit Your
Dealer” is displayed
Indicates that all maintenance is required 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 ha s been reset.) Per-
form the necessary maintenance. Please
reset the message after the maintenance is
performed. ( P.328)
*: Refer to the separa te “Scheduled Main-
tenance” or “Owner’s Manual Supple-
ment” for the maintenance interval
applicable to your vehicle.
■If “Oil Maintenance Required Soon” is
displayed
Indicates that the engine oil should be
scheduled to be changed.
Check the engine oil and change it if neces-
sary. After changing the engine oil, make
sure to reset the message. ( P.339)
■If “Oil Maintenance Required” is dis-
played
Indicates that the engine oil should be
changed.
Check and change the en gine oil, and oil fil-
ter by your Lexus deal er. After changing the
engine oil, make sure to reset the message.
(  P.339)
■If a message that in dicates the need for
visiting your Lexus dealer is displayed
The system or part shown on the multi-
information display is malfunctioning. Have
the vehicle inspected by your Lexus dealer
immediately.
■If a message that indicates the need for
referring to Owner’ s Manual is dis-
played
●If any of the following messages are
shown on the multi-information display,
follow the instructions.
• “Engine Coolant Temp High” ( P.410)
• “Front Camera Unavailable” ( P.196)
• “Radar Cruise Control Unavailable” ( P.196)
●If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malf unction. Have the
vehicle inspected by your Lexus dealer
immediately.
• “Access System with Elec. Key Malfunc-
tion”
• “Hybrid system malfunction”
•“Check Engine”
• “Hybrid battery system malfunction”
• “Accelerator system malfunction”
●If any of the following messages are
shown on the multi-info rmation display, it
may indicate a malfun ction. Immediately
stop the vehicle and contact your Lexus
dealer.
• “Braking Power Low”
• “Charging System Malfunction”
• “Oil Pressure Low”
●If “Low Auxiliary Battery See Owner’s
Manual” is shown
• When the display goes off after several
seconds
*:
Maintain the hybrid system operation for
more than 15 minutes and charge the 12-
volt battery.
• When the display does not go off:
Start up the hybrid system using the proce-
dures for “If the 12-volt battery is dis-
charged” ( P.405)
*: Displays for about 6 seconds
●If “Maintenance required for Traction bat-
tery cooling parts See owner’s manual” is
shown, the filter may be clogged, the air
intake vent may be blocked, or there may
be a gap in the duct. Therefore, perform
the following correction procedure.
• If the air intake vent and filter of the hybrid battery (traction battery) are dirty, per-

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

4117-2. Steps to take in an emergency
7
When trouble arises
and radiator 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 “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
5 Add coolant if necessary.
Water can be used in an emergency if coolant is unavailable.
6
Start the hybrid system and turn the
air conditioning system on to check
that the radiator cooling fans oper-
ate and to check for coolant leaks
from the radiator or hoses.
The fans operate when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fans are oper-
ating by checking the fan sound and air
flow. If it is difficult to check these, turn the
air conditioning system on and off repeat-
edly.
(The fans may not oper ate in freezing tem-
peratures.)
7 If the fans are not operating:
Stop the hybrid system immediately
and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the
nearest Lexus dealer.
8 Check if “Engine Coolant Temp
High Stop in a Safe Place See
Owner’s Manual” 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:
Have the vehicle inspected at the
nearest Lexus dealer.
A
B
A
B
C

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.