overheating LEXUS NX300h 2018 Owners Manual

832-1. Instrument cluster
LEXUS NX300h Owners Manu-
al_USA_OM78212U 2
Vehicle status information and indicators ■
Customization
The meter display can be customized on
the multi-information display.
(Customizable features: → P.419)
WARNING■
The information display at low tem-
peratures
Allow the interior of the vehicle to warm
up before using the liquid crystal infor-
mation display. At extremely low tem-
peratures, the in formation display
monitor may respond slowly, and display
changes may be delayed.
For example, there is a lag between the
driver's shifting and the new gear num-
ber appearing on the display. This lag
could cause the driver to downshift
again, causing rapid and excessive
engine braking and possibly an accident
resulting in personal death or injury.
NOTICE■
To prevent damage to the engine and
its components●
When the tachometer is displayed, do
not let the indicator needle of the
tachometer enter the red zone, which
indicates the maximum engine speed.
●
The engine may be overheating if the
engine coolant temperature gauge is
in the red zone (H); or “Engine Cool-
ant Temp High” or “Hybrid System
Overheated” is shown on the multi-
information display. In this case, imme-
diately stop the vehicle in a safe place,
and check the engine or hybrid system
after it has cooled completely.
( → P.394)

154 4-1. Before driving
LEXUS NX300h Owners Manu-
al_USA_OM78212U WARNING●
Always apply the parking brake, shift
the shift lever to P, stop the hybrid sys-
tem and lock the vehicle.
Do not leave the vehicle unattended
while the “READY” indicator is illumi-
nated.
If the vehicle is parked with the shift
lever in P but the parking brake is not
set, the vehicle may start to move, pos-
sibly leading to an accident.●
Do not touch the exhaust pipes while
the “READY” indicator is illuminated
or immediately after turning the hybrid
system off.
Doing so may cause burns.■
When taking a nap in the vehicle
Always turn the hybrid system off. Other-
wise, if you accidentally move the shift
lever or depress the accelerator pedal,
this could cause an accident or fire due
to hybrid system overheating. Addition-
ally, if the vehicle is parked in a poorly
ventilated area, exha ust gases may col-
lect and enter the ve hicle, leading to
death or a serious health hazard. ■
When braking●
When the brakes are wet, drive more
cautiously.
Braking distance increases when the
brakes are wet, and this may cause one
side of the vehicle to brake differently
than the other side. Also, the parking
brake may not securely hold the vehi-
cle.
●
If the electronically controlled brake
system does not operate, do not follow
other vehicles closely and avoid hills or
sharp turns that require braking.
In this case, braking is still possible, but
the brake pedal should be depressed
more firmly than usual. Also, the brak-
ing distance will increase. Have your
brakes fixed immediately. ●
The brake system consists of 2 or more
individual hydraulic systems; if one of
the systems fails, the other(s) will still
operate. In this case, the brake pedal
should be depressed more firmly than
usual and the braking distance will
increase. Have your brakes fixed
immediately. ■
If the vehicle becomes stuck
Do not spin the wheels excessively when
any of the tires is up in the air, or the vehi-
cle is stuck in sand, mud, etc. This may
damage the driveline components or
propel the vehicle forward or backward,
causing an accident.
NOTICE■
When driving the vehicle ●
Do not depress the accelerator and
brake pedals at the same time during
driving, as this may restrain the hybrid
system output. ●
Do not use the accelerator pedal or
depress the accelerator and brake
pedals at the same time to hold the
vehicle on a hill. ■
Avoiding damage to vehicle parts ●
Do not turn the steering wheel fully in
either direction and hold it there for an
extended period of time.
Doing so may damage the power
steering motor.
●
When driving over bumps in the road,
drive as slowly as possible to avoid
damaging the wheels, underside of the
vehicle, etc.
■
If you get a flat tire while driving
A flat or damaged tire may cause the fol-
lowing situations. Hold the steering
wheel firmly and gradually depress the
brake pedal to slow down the vehicle.
●
It may be difficult to control your vehi-
cle.

166 4-1. Before driving
LEXUS NX300h Owners Manu-
al_USA_OM78212U do not put the transmission in D.
( → P.176)
 Instability happens more frequently
when descending steep or long
downhill grades. Before descend-
ing, slow down and downshift. Do
not make sudden downshifts while
descending steep or long downhill
grades.
 Avoid holding the brake pedal down
too long or applying the brakes too
frequently. This could cause the
brakes to overheat and result in
reduced braking efficiency.
 Due to the added load of the trailer,
your vehicle’s engine may overheat
on hot days (at temperatures over
85°F [30°C]) when driving up a
long or steep grade. If the engine
coolant temperature gauge indi-
cates overheating, immediately turn
off the air conditioning (if in use),
pull your vehicle off the road and
stop in a safe spot. ( → P.394)
 Always place wheel blocks under
both the vehicle’s and the trailer’s
wheels when parking. Put the trans-
mission in P and apply the parking
brake. Avoid parking on a slope, but
if unavoidable, do so only after per-
forming the following:
1 Apply the brakes and keep them
applied.
2 Have someone place wheel blocks
under both the vehicle’s and trailer’s
wheels. 3 When the wheel blocks are in
place, release the brakes slowly
until the blocks absorb the load.
4 Shift into P and apply the parking
brake.
5 Turn off the hybrid system.
 When restarting after parking on a
slope:
1 With the transmission in P, start the
hybrid system. Be sure to keep the
brake pedal depressed.
2 Shift into a forward gear. If revers-
ing, shift into R.
3 If the parking brake is in manual
mode, release the parking brake.
( → P.179)
4 Release the brake pedal, and slowly
pull or back away from the wheel
blocks. Stop and apply the brakes.
5 Have someone retrieve the blocks.

1694-2. Driving procedures
LEXUS NX300h Owners Manu-
al_USA_OM78212U 4
Driving Check that the shift leve r is in P. Press the
power switch while turning the steering
wheel left and right.
●
To prevent the steering lock motor from
overheating, operation of the motor may
be suspended if the hybrid system is
turned on and off repeatedly in a short
period of time. In this case, refrain from
operating the hybrid system. After about
10 seconds, the stee ring lock motor will
resume functioning.■
If there is a malfun ction in the smart
access system with push-button start
If “Smart Access System Malfunction See
Owner’s Manual” is di splayed on the multi-
information display, the system may be mal-
functioning. Have the vehicle inspected by
your Lexus dealer immediately. ■
If the “READY” indicator does not come
on
In the event that the “READY” indicator
does not come on even after performing
the proper procedures for starting the vehi-
cle, contact your Lexus dealer immediately. ■
If the hybrid system is malfunctioning
→ P.67
■
Electronic key battery
→ P.347
■
Operation of the power switch
●
If the switch is not pressed shortly and
firmly, the power switch mode may not
change or the hybrid system may not
start.
●
If attempting to restart the hybrid system
immediately after turning the power
switch off, the hybrid system may not start
in some cases. After turning the power
switch off, please wait a few seconds
before restarting the hybrid system. ■
Customizable functions
→ P.421
1 Stop the vehicle completely.
2 Set the parking brake ( → P.179),
and shift the shift lever to P
( → P.173).
3 Press the power switch. WARNING■
When starting the hybrid system
Always start the hybrid system while sit-
ting in the driver’s seat. Do not depress
the accelerator pedal while starting the
hybrid system under any circumstances.
Doing so may cause an accident result-
ing in death or serious injury. ■
Caution while driving
If hybrid system failure occurs while the
vehicle is moving, do not lock or open the
doors until the vehicle reaches a safe and
complete stop. The steering lock func-
tion will activate and this may lead to an
accident, resulting in death or serious
injury.
NOTICE■
When starting the hybrid system ●
If the hybrid system becomes difficult
to start, have your vehicle checked by
your Lexus dealer immediately.
NOTICE■
Symptoms indicating a malfunction
with the power switch
If the power switch seems to be operat-
ing somewhat differently than usual, such
as the switch sticking slightly, there may
be a malfunction. Contact your Lexus
dealer immediately.
Stopping the hybrid system

1774-2. Driving procedures
LEXUS NX300h Owners Manu-
al_USA_OM78212U 4
Driving ■
Parking brake operation●
When the power switch is not in ON
mode, the parking brake cannot be
released using the parking brake switch.●
When the power switch is not in ON
mode, automatic mode (automatic brake
setting and releasing) is not available.■
If “Parking Brake Overheated Parking
Brake Unavailable” is displayed on the
multi-information display
If the parking brake is operated repeatedly
over a short period of time, the system may
restrict operation to prevent overheating. If
this happens, refrain from operating the
parking brake. Normal operation will return
after about 1 minute. ■
Parking brake operation sound
When the parking brake operates, a motor
sound (whirring sound) may be heard. This
does not indicate a malfunction.
■
Parking brake indicator light and park-
ing brake lamp
●
Depending on the power switch mode,
the parking brake in dicator light and
parking brake lamp will turn on and stay
on as described below:
ON mode: Comes on until the parking
brake is released.
Not in ON mode: Stays on for approxi-
mately 15 seconds.
●
When the power switch is turned off with
the parking brake set, the parking brake
indicator light and parking brake lamp
will stay on for about 15 seconds. This does not indicate a malfunction. ■
Changing the mode
When changing the automatic mode on/off,
the message will be shown on the multi-
information display and the buzzer sounds. ■
Parking brake engaged warning buzzer
A buzzer will sound if the vehicle is driven
with the parking brake engaged. “Release
Parking Brake” is displayed on the multi-
information display. ■
Warning messages and buzzers
Warning messages and buzzers are used to
indicate a system malfunction or to inform
the driver of the need for caution. If a warn-
ing message is shown on the multi-informa-
tion display, read the message and follow
the instructions. ■
If the brake system warning light comes
on
→ P.366 ■
Usage in winter time
→ P.258Parking brake The parking brake can be set or
released automatically or manually.
In automatic mode, the parking
brake can be set or released auto-
matically according to shift lever
operation. Also, even in automatic
mode, the parking brake can be set
or released manually.
WARNING■
When parking the vehicle
Do not leave a child in the vehicle alone.
The parking brake may be released unin-
tentionally and there is the danger of the
vehicle moving that may lead to an acci-
dent resulting in death or serious injury.
NOTICE
■
When parking the vehicle
Before you leave the vehicle, shift the
shift lever to P, set the parking brake and
make sure that the vehicle does not
move.
■
When the system malfunctions
Stop the vehicle in a safe place and
check the warning messages.

178 4-2. Driving procedures
LEXUS NX300h Owners Manu-
al_USA_OM78212U ■
Turns automatic mode on
While the vehicle is stopped, pull and
hold the parking brake switch until the
automatic mode lamp turns on
Parking brake indicator (U.S.A.)
Parking brake indicator (Canada)
Parking brake lamp
Automatic mode lamp
The parking brake is set or released
automatically according to shift lever operation.
 When the shift lever is moved out of
P, the parking brake will be released,
and the parking brake indicator light
and parking brake lamp turn off.
 When the shift lever is moved into P,
the parking brake will be set, and the
parking brake indicator light and
parking brake lamp turn on. Operate the shift lever with the brake
pedal depressed. ■
Turns automatic mode off
While the vehicle is stopped, press and
hold the parking brake switch until the
automatic mode lamp turns off
Parking brake indicator (U.S.A.)
Parking brake indicator (Canada)
Parking brake lamp
Automatic mode lampNOTICE■
When the parking brake cannot be
released due to a malfunction
Driving the vehicle with the parking
brake set will lead to brake components
overheating, which may affect braking
performance and increase brake wear.
Have the vehicle inspected by contact
your Lexus dealer immediately if this
occurs.
Operating instructions
A
B
C
D A
B
C
D

2775-2. Using the air conditio ning system and defogger
LEXUS NX300h Owners Manu-
al_USA_OM78212U 5
Interior features ■
Operation condition
The seat heaters can be used when the
power switch is in ON mode.
Each time the switch is pressed, the
operation condition changes as fol-
lows.
Hi (3 segments lit) → Mid (2 segments
lit) → Lo (1 segment lit) → OffThe indicator (green) and level indicator
(green) light up during operation. ■
Operation condition
The power switch is in ON mode.
WARNING■
To prevent causes of overheating and
minor burn injuries
Observe the following precautions when
using a seat heater ●
Do not cover the seat with a blanket or
cushion when using the seat heater.●
Do not use seat heater more than nec-
essary.
Seat ventilators (front)
A

366 7-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_OM78212U ■
High coolant temperature warning light (warning buzzer) *
*
: This light illuminates on the multi-information display. ■
Brake system warning light
■
Malfunction indicator lamp
■
SRS warning light Warning light Details/Actions
Indicates that the engine is overheating
→ Immediately stop the vehicle in a safe place. Continu-
ing to drive the vehicle may be dangerous.
Handling method ( → P.394)
Warning light Details/Actions
(Yellow)
Indicates a malfunction in:
 The regenerative braking system;
 The electronically controlled brake system; or
 The electric parking brake
→ Have the vehicle inspected by your Lexus dealer
immediately.
Warning light Details/Actions
(U.S.A.)
(Canada) Indicates a malfunction in:
 The hybrid system;
 The electronic engine control system;
 The electronic throttle control system; or
 The emission control system
→ Have the vehicle inspected by your Lexus dealer
immediately.
Warning light Details/Actions
Indicates a malfunction in:
 The SRS airbag system;
 The front passenger occupant classification system; or
 The seat belt pretensioner system
→ Have the vehicle inspected by your Lexus dealer
immediately.

394 7-2. Steps to take in an emergency
LEXUS NX300h Owners Manu-
al_USA_OM78212U 
“Engine Coolant Temp High” is
shown on the multi-information dis-
play
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 and radiator core (radiator) for any
leaks.
Radiator
Cooling fans If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4 The 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 If your vehicle overheats The following may indicate that
your vehicle is overheating.
 The needle of the engine coolant
temperature gauge ( → P.79)
enters the red zone, or a loss of
hybrid system power is experi-
enced. (For example, the vehicle
speed does not increase.)
 “Engine Coolant Temp High” or
“Hybrid System Overheated” is
shown on the multi-information
display.
 Steam comes out from under the
hood.
Correction procedures A
B
A
B
C

448 Alphabetical Index
LEXUS NX300h Owners Manu-
al_USA_OM78212U Brake
Brake Hold .................................................... 180
Fluid ..................................................................405
Parking brake ................................................ 177
Regenerative braking ................................. 62
Warning light ...............................................366
Brake assist .................................................... 250
Brake Hold ...................................................... 180
Break-in tips...................................................... 151
Brightness control
Instrument panel light control ................ 84
BSM (Blind Spot Monitor)......................... 241
Blind Spot Monitor function................. 243
Rear Cross Traffic Alert function....... 246
BSM (Blind Spot Monitor) main switch241
C
Card key ...........................................................102
Care
Aluminum wheels ........................................314
Exterior ............................................................. 314
Interior ............................................................... 314
Seat belts.......................................................... 317
Cargo capacity...................................155, 400
Cargo hooks ................................................. 284
Cargo net hooks .......................................... 284
Chains .............................................................. 258
Child restraint system....................................47
Booster seats installation .......................... 53
Convertible seats installation.................. 52
Front passenger occupa nt classification
system ............................................................... 41
Infant seats definition................................... 49
Infant seats installation .................................. 51
Installing CRS with LATCH anchors . 55
Installing CRS with seat belts.................... 51
Installing CRS with top tether strap..... 57
LATCH anchors ........................................... 55
Child safety ....................................................... 46
12-volt battery precautions .......334, 393
Airbag precautions.......................................37
Back door precautions.............................. 110 Child restraint system ................................. 47
How your child should wear the seat belt
............................................................................. 28
Installing child restraints............................. 47
Moon roof precautions............................ 148
Power window lock switch .................... 145
Power window precautions .................. 145
Rear door child-protectors ................... 109
Removed key battery precautions... 348
Seat belt extender precautions.............. 28
Seat belt precautions .................................. 46
Seat heater precautions.......................... 275
Child-protectors........................................... 109
Cleaning .................................................. 314, 317
Aluminum wheels ........................................314
Exterior..............................................................314
Interior ...............................................................317
Seat belts ..........................................................317
Clock ................................................................288
Compass ......................................................... 303
Condenser .......................................................331
Console box .................................................. 282
Consumption screen .................................... 94
Coolant
Capacity ........................................................ 403
Checking ...................................................... 330
Preparing and checking before winter
.......................................................................... 257
Warning light .............................................. 366
Cooling system............................................. 330
Hybrid system overheating ..................394
Cruise control
Dynamic radar cruise control with full-
speed range ............................................... 217
Cup holders ................................................... 282
Curtain shield airbags .................................. 32
Customizable features ................................419
D
Daytime running light system .................. 184
Deck board .................................................... 285
Deck under tray ........................................... 285