overheating LEXUS RX450H 2016 Owners Manual

841-3. Hybrid system
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WARNING
■Hybrid battery (traction battery)
●Never resell, hand over or modify the hybrid battery. To prevent accidents, hybrid
batteries that have been removed from a disposed vehicle are collected through
Lexus dealer. Do not dispose of the battery yourself.
Unless the battery is properly collected, the following may occur, resulting in death
or serious injury:
• The hybrid battery may be illegally disposed of or dumped, and it is hazardous to
the environment or someone may touch a high voltage part, resulting in an electric
shock.
• The hybrid battery is intended to be used exclusively with your hybrid vehicle. If the hybrid battery is used outside of your vehicle or modified in any way, accidents
such as electric shock, heat generation , smoke generation, an explosion and elec-
trolyte leakage may occur.
When reselling or handing over your vehicle, the possibility of an accident is
extremely high because the person receiving the vehicle may not be aware of these
dangers.
●If your vehicle is disposed of without the hybrid battery having been removed, there is
a danger of serious electric shock if high voltage parts, cables and their connectors
are touched. In the event that your vehicle must be disposed of, the hybrid battery
must be disposed of by your Lexus dealer or a qualified service shop. If the hybrid bat-
tery is not disposed of properly, it may cause electric shock that can result in death or
serious injury.
NOTICE
■Hybrid battery (traction battery) air intake/discharge vents
●Do not place objects that will block the air intake vents. The hybrid battery (traction
battery) may overheat and be damaged.
●Clean the air intake/discharge vents regularl y to prevent the hybrid battery (traction
battery) from overheating.
●Do not get water or foreign materials in either the air intake/discharge vents as this
may cause a short circuit and damage the hybrid battery (traction battery).
●Do not carry large amounts of water such as water cooler bottles in the vehicle. If
water spills onto the hybrid battery (tract ion battery), the battery may be damaged.
Have the vehicle inspected by your Lexus dealer.

1012. Instrument cluster
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Instrument cluster
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■Tachometer
Hybrid System Indicator switches to the tachometer when driving mode is in sport mode.
The settings of the tachometer display can be changed on of the multi-information
display. ( P. 109)
■Engine speed
On hybrid vehicles, engine speed is precisel y controlled in order to help improve fuel
efficiency and reduce exhaust emissions etc.
There are times when the engine speed that is displayed may differ even when vehicle
operation and driving conditions are the same.
■Brightness of the meters (d ay mode and night mode)
The brightness of the meters is changed between day mode and night mode.
●Day mode: When the tail lights are off or when the tail lights are on but the surrounding
area is bright
●Night mode: When the tail lights are on and the surrounding area is dark
■Outside temperature display
●In the following situations, the correct outside temperature may not be displayed, or the
display may take longer than normal to change.
• When stopped, or driving at low speeds (less than 12 mph [20 km/h])
• When the outside temperature has changed suddenly (at the entrance/exit of a garage, tunnel, etc.)
●When “ ” or “E” is displayed, the sy stem may be malfunctioning.
Take your vehicle to your Lexus dealer.
■Clock settings screen
If the clock adjustment screen is displayed continuously when attempting to change the
clock settings, the system may be malfunctioning.
Have the vehicle inspected by your Lexus dealer.
■Customization
Some functions can be customized. ( P. 109)
NOTICE
■To prevent damage to the engine and its components
●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). In this case, immediately stop the vehicle in a safe place, and check the
engine after it has cooled completely. ( P. 574)

2104-1. Before driving
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WARNING
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When taking a nap in the vehicle
Always turn the hybrid system off. Otherwise, if you accidentally move the shift lever or
depress the accelerator pedal, this could cause an accident or fire due to hybrid system
overheating. Additionally, if the vehicle is parked in a poorly ve ntilated area, exhaust
gases may collect and enter the vehicle, lead ing 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 vehicle.
●If the electronically controlled brake function 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, bu t the brake pedal should be depressed more
firmly than usual. Also, the braking distan ce will increase. Have your brakes fixed
immediately.
●The brake system consists of 2 or more indi vidual hydraulic systems; if one of the sys-
tems 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 (AWD models)
Do not spin the wheels excessive ly when any of the tires is up in the air, or the vehicle is
stuck in sand, mud, etc. This may damage the driveline components or propel the vehi-
cle forward or backward, causing an accident.

2254-1. Before driving
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Driving
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●To maintain engine braking efficiency and charging system performance
when using engine braking, do no t put the transmission in D. (P. 239)
●Instability happens more fr equently when descending steep or long downhill
grades. Before descending, slow down and downshift. Do not make sudden
downshifts while descending st eep or long downhill grades.
●Avoid holding the brake pedal down too long or applying the brakes too fre-
quently. This could cause the brakes to overheat and result in reduced braking
efficiency.
●Due to the added load of the trailer, yo ur 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 temperat ure gauge indicates overheating, imme-
diately turn off the air conditioning (if in use), pull your vehicle off the road and
stop in a safe spot. ( P. 574)
●Always place wheel blocks under both the vehicle’s and the trailer’s wheels
when parking. Put the transmission in P and apply the parking brake. Avoid
parking on a slope, but if unavoidable, do so only after performing the follow-
ing:
Apply the brakes and keep them applied.
Have someone place wheel blocks under both the vehicle’s and trailer’s
wheels.
When the wheel blocks are in place, release the brakes slowly until the
blocks absorb the load.
Shift into P and apply the parking brake.
Turn off the hybrid system.
●When restarting afte r parking on a slope:
With the transmission in P, start the hybrid system. Be sure to keep the
brake pedal depressed.
Shift into a forward gear. If reversing, shift into R.
If the parking brake is in manual mode, release the parking brake.
( P. 246)
Release the brake pedal, and slowly pull or back away from the wheel
blocks. Stop and apply the brakes.
Have someone retrieve the blocks.
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2354-2. Driving procedures
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Driving
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■Steering lock
After turning the power switch off and opening and closing the doors, the steering wheel
will be locked due to the steering lock func tion. Operating the power switch again auto-
matically cancels the steering lock.
■When the steering lock cannot be released
■Steering lock motor overheating prevention
To prevent the steering lock motor from overheating, operation of the motor may be sus-
pended if the hybrid system is turned on an d off repeatedly in a short period of time. In
this case, refrain from operating the hybrid system. Afte r about 10 seconds, the steering
lock motor will resume functioning.
■When “Access System with Elec. Key Malf unction See Owner’s Manual” is displayed
on the multi-information display
The system may be malfunctio ning. 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 vehicl e, contact your Lexus dealer immediately.
■If the hybrid system is malfunctioning
P. 81
■If the electronic key battery is depleted
P. 506
■Operation of the power switch
●When operating the power switch, one short, firm press is enough. If the switch is
pressed improperly, the hybrid system may no t start or the power switch mode may not
change. It is not necessary to press and hold the switch.
●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 seco nds before restarting the hybrid system.
■If the smart access system wi th push-button start has been deactivated by a customized
setting
 P. 564
“Steering Wheel Lock Pr
ess Power Switch while
Turning Wheel” will be displayed on the multi-
information display.
Check that the shift lever is in P. Press the power
switch while turning the steering wheel left and
right.

2464-2. Driving procedures
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The parking brake can be set and released manually. Sets the parking brake
The parking brake indicator light and
parking brake lamp will turn on.
Pull and hold the parking brake switch if
an emergency occurs and it is necessary
to operate the parking brake while driv-
ing.
Releases the parking brake
Operate the parking brake switch while
depressing the brake pedal. Make sure
that the parking brake indicator light
and parking brake lamp turn off.
If the parking brake indicator light and
parking brake lamp flashes, operate the
switch again. ( P. 536)
■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 Brak e 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 wi ll return after about 1 minute.
■If “EPB Activation Stopped Incompletely” or “Parking Brake Unavailable” is displayed
on the multi-information display
Operate the parking brake switch. If the message does not disappear after operating the
switch several times, the system may be ma lfunctioning. Have the vehicle inspected by
your Lexus dealer immediately.
Manual mode
U.S.A. Canada
Parking
brake lamp
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3854-5. Using the driving support systems
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Driving
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■Reactivation of the TRAC system linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehicle
speed increases. However, when TRAC, VSC and Trailer Sway Control systems are
turned off, the systems will not turn on even when vehicle speed increases.
■Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating
when there is frequent steering input over an extended period of time. The steering
wheel may feel heavy as a result . Should this occur, refrain from excessive steering input
or stop the vehicle and turn the hybrid system off. The EPS system should return to nor-
mal within 10 minutes.
■Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate:
●The shift lever is in a position other than P or N (when starting off forward/backward on
an upward incline).
●The vehicle is stopped.
●The accelerator pedal is not depressed.
●The parking brake is not engaged.
■Automatic system cancelation of hill-start assist control
The hill-start assist control will turn off in any of the following situations:
●The shift lever is moved to P or N.
●The accelerator pedal is depressed.
●The parking brake is engaged.
●Approximately 2 seconds elapse af ter the brake pedal is released.
WARNING
■The ABS does not operate effectively when
●The limits of tire gripping performance have been exceeded (such as excessively
worn tires on a snow covered road).
●The vehicle hydroplanes while driving at high speed on wet or slick roads.
■Stopping distance when the ABS is operating may exceed that of normal conditions
The ABS is not designed to shorten the vehi cle’s stopping distance. Always maintain a
safe distance from the vehicle in front of you, especially in the following situations:
●When driving on dirt, grav el or snow-covered roads
●When driving with tire chains
●When driving over bumps in the road
●When driving over roads with potholes or uneven surfaces
■TRAC may not operate effectively when
Directional control and power may not be achievable wh ile driving on slippery road
surfaces, even if the TRAC system is operating.
Drive the vehicle carefully in conditions where stability and power may be lost.

4145-2. Using the air conditioning system and defogger
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Heated steering wheel/seat heaters/seat ventila-
tors
: If equipped
Heated steering wheel and seat heaters heat the side grips of the steering
wheel and seats, respectively. Seat ventilators maintain good airflow by blow-
ing air from the seats.
WARNING
●Care should be taken to prevent injury if anyone in the following categories comes in
contact with the steering wheel and seats when the heater is on:
• Babies, small children, the elderly, the sick and the physically challenged
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (sleeping drugs, cold
remedies, etc.)
●Observe the following precautions to prevent minor burns or overheating:
• Do not cover the seat with a blanket or cushion when using the seat heater.
• Do not use seat heater more than necessary.
NOTICE
●Do not put heavy objects that have an unev en surface on the seat and do not stick
sharp objects (needles, nails, etc.) into the seat.
●To prevent 12-volt battery discharge, do not use the functions when the hybrid system
is off.

5747-2. Steps to take in an emergency
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■“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information displayStop 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 (radi-
ator) for any leaks.Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The coolant level is satisfactory if
it is between the “FULL” and
“LOW” lines on the reservoir.Reservoir
“FULL” line
“LOW” line
Radiator cap
If your vehicle overheats
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( P. 97) enters the
red zone, or a loss of hybrid system 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 Overheated Reduced Output Power” is shown on the
multi-information display.
●Steam comes out from under the hood.
Correction procedures
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643Alphabetical index
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CoolantCapacity ................................................ 587
Checking................................................ 479
Preparing and checking before winter ................................... 390
Cooling system ..................................... 479 Hybrid system overheating ..........574
Cornering lights .................................... 252
Cruise control Cruise control..................................... 335
Dynamic radar cruise control...... 323
Dynamic radar cruise control with full-speed range ....................... 311
Cup holders ............................................ 423
Curtain shield airbags ........................... 39
Customizable features ....................... 607
Customized mode ................................377 Daytime running light system.......... 253
Defogger
Outside rear view mirrors ............409
Rear window........................................409
Windshield............................................409
Differential .............................................. 588
Dimension ............................................... 582
Dinghy towing ......................................... 231
Display Dynamic radar cruise control ..... 323
Dynamic radar cruise control with full-speed range .......................311
Energy monitor..................................... 124
LDA (Lane Departure Alert with steering control) ...................306
LKA (Lane-Keeping Assist)......... 297
Multi-information display.................102
Warning messages .......................... 543
Do-it-yourself maintenance............... 471
Doors Automatic door locking and unlocking system..............................139
Door lock................................................ 138
Outside rear view mirrors ............. 185
Power back door ................................ 142
Rear door child-p rotectors ............139
Side doors ...............................................136
Side windows ....................................... 189
Drive information ................................... 106
Drive-start control .................... 205, 242
Driver’s seat belt reminder light .... 538
Driver’s seat position memory.......... 174D