engine overheat LEXUS RX450h 2015 Owners Manual

TABLE OF CONTENTS Index
64-1. Maintenance and care
Cleaning and protecting
the vehicle exterior................... 634
Cleaning and protecting
the vehicle interior .................... 637
4-2. Maintenance
Maintenance requirements .... 640
General maintenance ................ 643
Emission inspection and
maintenance (I/M)
programs ...................................... 647
4-3. Do-it-yourself maintenance
Do-it-yourself service
precautions ................................. 648
Hood................................................... 651
Positioning a floor jack............... 652
Engine compartment.................. 654
12-volt battery................................ 664
Tires ................................................... 670
Tire inflation pressure ................. 679
Wheels............................................. 683
Air conditioning filter ................. 685
Electronic key battery ................ 687
Checking and replacing
fuses ............................................... 689
Headlight aim................................. 705
Light bulbs ...................................... 708 5-1. Essential information
Emergency flashers..................... 724
If your vehicle needs to be
towed.............................................. 725
If you think something is
wrong ............................................. 732
5-2. Steps to take in an emergency
If a warning light turns on
or a warning buzzer
sounds... ........................................ 733
If a warning message is
displayed ....................................... 743
If you have a flat tire..................... 764
If the hybrid system will not
start ................................................. 777
If the shift lever cannot be
shifted from P .............................. 779
If you lose your keys ................... 780
If the electronic key does
not operate properly ................ 781
If the vehicle 12-volt battery
is discharged ............................... 784
If your vehicle overheats .......... 788
If the vehicle becomes
stuck................................................ 793
If your vehicle has to be
stopped in an em ergency ...... 7954
Maintenance and care 5
When trouble arises

1702-1. Driving procedures
CAUTION●
Do not shift the shift lever to R while the vehicle is moving forward.
Doing so can damage the transmission and may result in a loss of vehicle control.●
Do not shift the shift lever to D while the vehicle is moving backward.
Doing so can damage the transmission and may result in a loss of vehicle control.●
Moving the shift lever to N while the vehicle is moving will disengage the hybrid
system. Engine braking is not availabl e with the hybrid system disengaged.●
During normal driving, do not turn off the hybrid system. Turning the hybrid sys-
tem off while driving will not cause loss of steering or braking control, however,
power assist to the steering will be lost. This will make it more difficult to steer
smoothly, so you should pull over and stop the vehicle as soon as it is safe to do so.
In the event of an emergency, such as if it becomes impossible to stop the vehicle
in the normal way:  P. 7 9 5●
Use engine braking (downshift) to maintain a safe speed when driving down a
steep hill.
Using the brakes continuously may cause the brakes to overheat and lose effec-
tiveness. (  P. 1 8 6 )●
When stopped on an incline, use the brake pedal and parking brake to prevent
the vehicle from rolling backward or forward, causing an accident. ●
Do not adjust the position of the steering wheel, the seat, or the inside or outside
rear view mirrors while driving.
Doing so may result in a loss of vehicle control that can cause accidents, resulting
in death or serious injury.●
Always check that all passengers' arms, heads or other parts of their body are not
outside the vehicle, as this may result in death or serious injury.●
Do not drive in excess of the speed limit. Even if the legal speed limit permits it, do
not drive over 85 mph (140 km/h) unless your vehicle has high-speed capability
tires. Driving over 85 mph (140 km/h) may result in tire failure, loss of control and
possible injury. Be sure to consult a tire dealer to determine whether the tires on
your vehicle are high-speed capability tires or not before driving at such speeds.

1722-1. Driving procedures
CAUTION■
When the vehicle is stopped ●
Do not depress the accelerator pedal unnecessarily.
If the vehicle is in any gear other than P or N, the vehicle may accelerate suddenly
and unexpectedly, causing an accident.●
Do not leave the vehicle with the hybrid system on for a long time.
If such a situation cannot be avoided, park the vehicle in an open space and
check that exhaust fumes do no t enter the vehicle interior.●
In order to prevent accidents due to the vehicle rolling away, always keep
depressing the brake pedal while the “READY” indicator is on. Apply the parking
brake as necessary.●
If the vehicle is stopped on an incline, in order to prevent accidents caused by the
vehicle rolling forward or backward, always depress the brake pedal and securely
apply the parking brake as needed.●
Avoid revving or racing the engine.
Running the engine at high speed while the vehicle is stopped may cause the
exhaust system to overheat, which could result in a fire if combustible material is
nearby.

2002-2. Instrument cluster
NOTICE■
To prevent damage to the engine and its components
The engine may be overheating if the engi ne coolant temperature gauge is in the
red zone (H). In this case, immediately stop the vehicle in a safe place, and check
the engine after it has cooled completely. (  P. 7 8 8 )

3172-5. Driving information
2
When driving ● Avoid jerky steering and sharp turns, and slow down before making a
turn.
● Note that when making a turn, the tr ailer wheels will be closer than the
vehicle wheels to the inside of th e turn. Compensate by making a
wider than normal turning radius.
● Slow down before making a turn, in cross winds, on wet or slippery sur-
faces, etc.
Increasing vehicle speed can destabilize the trailer.
● Take care when passing other vehi cles. Passing requires considerable
distance. After passing a vehicle, do not forget the length of your
trailer, and be sure you have plenty of room before changing lanes.
● To maintain engine braking efficiency and charging system perfor-
mance when using engine braking, do not put the transmission in D.
● Instability happens more frequently when descending steep or long
downhill grades. Before descending, 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 th e 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 eng ine coolant temperature gauge indicates
overheating, immediately turn off th e air conditioning (if in use), pull
your vehicle off the road and stop in a safe spot. (  P. 7 8 8 )

7525-2. Steps to take in an emergency
(Flashes)
(If equipped) Indicates that there is a
high possibility of a fron-
tal collision, or that the
pre-collision braking
function is operating
A buzzer also sounds.
At the same time,
will appear on
the head-up display (the
image flashes). Slow the vehicle by apply-
ing the brakes.
(Flashes)
(If equipped) Indicates that your vehi-
cle is nearing the vehicle
ahead (in radar cruise
mode)
A buzzer also sounds.
At the same time,
will appear on
the head-up display (the
image flashes). Slow the vehicle by apply-
ing the brakes.
Indicates that the engine
has overheated
A buzzer also sounds. Stop and check.
(  P. 7 8 8 )Wa r n i n g m e s s a g e Details Correction procedure

7885-2. Steps to take in an emergency
If your vehicle overheats
Correction procedures
■ If “ENGINE OVERHEAT” is shown on the multi-information display
Stop the vehicle in a safe place and turn off the air conditioning
system, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
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,
immediately contact your Lexus
dealer.The following may indicate that your vehicle is overheating.
● “ENGINE OVERHEAT” is shown on the multi-information display:
The engine may be overheating.
● “HYBRID SYSTEM OVERHEAT” is sh own on the multi-information
display:
A hybrid system component such as the power control unit or an
electric motor (traction motor) may be overheating.
● Steam comes out from under the hood. STEP 1
STEP 2
STEP 3

864Alphabetical index
Engine
Accessory mode ................................. 177
Compartment .....................................654
Hood......................................................... 651
How to start the hybrid
system .................................................... 177
Identification number....................... 799
If the hybrid system will
not start ................................................777
Ignition switch........................................ 177
Overheating.........................................788
“POWER” switch ................................ 177
Engine compartment cover .............655
Engine coolant
Capacity ................................................ 804
Checking ...............................................659
Preparing and checking
before winter .................................... 302
Engine coolant temperature
gauge....................................................... 197
Engine oil
Capacity .................................................802
Checking ...............................................656
Preparing and checking
before winter .................................... 302
EPS ...............................................................271
EV drive mode ........................................ 183
Event data recorder ............................... 25 Floor mat ................................................... 610
Fluid
Brake .......................................................806
Washer................................................... 663
Fog lights
Replacing light bulbs ....................... 708
Switch .........................................................221
Wattage .................................................809
Footwell light .......................................... 582
Front fog lights
Replacing light bulbs ....................... 708
Switch .........................................................221
Wattage .................................................809
Front passenger occupant
classification system ...........................145
Front passenger's seat belt
reminder light ..................................... 736
Front seats
Adjustment .............................................. 86
Driving position memory ..................93
Flattening seatbacks ............................87
Front side marker lights
Replacing light bulbs ....................... 708
Front turn signal lights
Replacing light bulbs ....................... 708
Wattage .................................................809F

867Alphabetical index
Shift lever light ..................................... 582
Turn signal lever................................... 193
Vanity lights .......................................... 596
Wattage ................................................ 809
Load capacity ..........................................301
Lock steering column.......................... 180
Luggage compartment lights
Switch .......................................................... 77
Wattage ................................................ 809
Luggage cover ........................................ 613
Maintenance
Do-it-yourself maintenance ......... 648
General maintenance ..................... 643
Maintenance data ............................. 798
Maintenance requirements .......... 640
Meter
Instrument panel light control .......198
Meters ....................................................... 197
Mirrors
Inside rear view mirror ..................... 107
Side mirror heaters* ........................358
Side mirrors............................................109
Vanity mirrors ..................................... 596
Mobile Assistant*................................. 340
Moon roof .................................................. 115
MP3 disc* ..................................... 381, 493
Multi-display light control................. 600
Multi-information display
Switches ................................................. 206
Trip information .................................. 209 Noise from under vehicle..................... 22
Odometer..................................................197
Oil
Engine oil............................................... 656
Opener
Back door ................................................. 75
Fuel filler door ......................................... 119
Hood ......................................................... 651
Outer foot lights
Outer foot lights ................................ 582
Wattage ................................................. 809
Outside rear view mirrors
Adjusting and folding........................ 109
Mirror position memory .................... 93
Outside temperature display* ....... 598
Overhead console ............................... 592
Overhead courtesy lights
Overhead courtesy lights............. 582
Wattage ................................................. 809
Overheating, Hybrid system ...........788M
*: For vehicles with a navigation system, refer to the “Navigation System Owner’s Manual”. N O

873Alphabetical index
Warning messages
Anti-lock brake system .................. 745
AWD system ............................744, 745
Brake lamp system ........................... 745
Brake system ........................................743
Dynamic radar cruise
control system ..................... 745, 748
Electric power steering .................. 745
Engine oil maintenance.................. 748
Engine oil pressure............................744
Engine overheat................................. 748
Headlight leveling ............................. 745
Hood ....................................................... 748
Intuitive parking assist ......... 745, 748
Low fuel .................................................. 748
Moon roof ............................................. 748
Open door ........................................... 748
Parking brake ...................................... 748
Pre-collision system ............. 745, 748
Smart access system with
push-button start............................ 756
SRS airbags .......................................... 745
Steering lock ........................................ 745
Washer fluid......................................... 748 Washer
Checking .............................................. 663
Preparing and checking
before winter ....................................302
Switch....................................................... 223
Washing and waxing ........................... 634
Weight
Cargo capacity .................................... 301
Load limits .............................................. 301
Weight.................................................... 798
Wheels ......................................................683
Window glasses ...................................... 112
Window lock switch ............................... 112
Windows
Power windows ..................................... 112
Rear window defogger* ............... 358
Washer ................................................... 223
Windshield wiper de-icer* ...............360
Windshield wipers................................ 223
Wireless remote control....................... 69
Wireless remote control key
Replacing the battery...................... 687
WMA disc* ...................................381, 493
*: For vehicles with a navigation system, refer to the “Navigation System Owner’s Manual”.