2017 LEXUS RX300H overheating

15Pictorial index
RC300h_EE(OM24740E)
Windshield wipers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 241
Precautions against winter season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 337
To prevent freezing (windshield wiper de-icer)*1 . . . . . . . . . . . . . . . . . . . . . . P. 439 Precautions against car wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 462
Fuel filler door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P . 249
Refueling method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 249 Fuel type/fuel tank capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 598
Tires. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 484
Tire size/inflation pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 604 Winter tires/tire chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 33 7
Checking/rotation/tire pressure warning system . . . . . . . . . . . . . . . . . . . . . . P. 484 Coping with flat tires. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 563
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 471
Opening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 471 Engine oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 599 Coping with overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 587
Warning messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 544
Headlights/front position lights/daytime running lights/
turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 229, 232
Front fog lights*1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 239
Rear fog light*3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 239
Back up light*2
Shifting the shift lever to R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 222
Tail lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 232
Stop lights
Emergency brake signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 305
License plate lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 232
Rear fog light*2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 239
Back up light*3
Shifting the shift lever to R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 222
4
5
6
7
Light bulbs of the exterior lights for driving
(Replacing method: P. 518, Watts: P. 605)
*1: If equipped
*2: Left-hand drive vehicles
*3: Right-hand drive vehicles
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9
10
11
12
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941-2. Hybrid system
RC300h_EE(OM24740E)
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 any
authorized Lexus dealer or repairer, or an other duly qualified and equipped profes- sional. 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 dispos ed 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 batterymust be disposed of by any authorized Lexu s dealer or repairer, or another duly qual-
ified and equipped professional. If the hybrid battery 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 vent
●Do not place objects that will block the air intake vent. The hybrid battery (traction
battery) may overheat and be damaged.
●Clean the air intake vent regularly to prevent the hybrid battery (traction battery) from overheating.
●Do not get water or foreign materials in the air intake vent as this may cause a shortcircuit 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 any authorized Lexus dealer or repairer, or anotherduly qualified and equipped professional.

1202. Instrument cluster
RC300h_EE(OM24740E)
■Pop-up display
●In some situations, such as when a switch operation is performed, a pop-up display will be temporarily displayed on the multi-information display or the odometer/trip meter
screen (F SPORT models only).
●Some pop-up displays can be set on/off. ( P. 126)
■Liquid crystal display
Small spots or light spots may appear on th e display. This phenomenon is characteristic of liquid crystal displays, and there is no problem continuing to use the display.
■Customization
The meter display can be customized on the multi-information display. (P. 121)
NOTICE
■To prevent damage to the engine and its components
●Do not let the indicator of the tachometer enter the red zone, as it represents the engine speed range which exceeds the maximum safe engine speed.
●If the engine coolant temperature gauge is in the red zone (H), the engine may beoverheating. In this case, immediately stop the vehicle in a safe place, and check theengine after it has cooled completely. ( P. 587)

2114-1. Before driving
4
Driving
RC300h_EE(OM24740E)
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. Otherwis e, if you accidentally move the shift lever or depress the accelerator pedal, this could cause an accident or fire due to hybrid systemoverheating. Additionally, if the vehicle is parked in a poorly ventilated 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 notsecurely hold the vehicle.
●If the electronically controlled brake system does not operate, do not follow othervehicles 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 distance will increase. Have your brakes fixed immediately.
●The brake system consists of 2 or more individual 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
Do not spin the wheels excessively when any of the tires is up in the air, or the vehicle is stuck in sand, mud, etc. This may damage th e driveline components or propel the vehi-
cle forward or backward, causing an accident.

2174-2. Driving procedures
4
Driving
RC300h_EE(OM24740E)
■Auto power off function
If the vehicle is left in ACCESSORY mode for more than 20 minutes or ON mode (the hybrid system is not operating) for more than an hour with the shift lever in P, the power switch will automatically turn off. However, th is function cannot entirely prevent 12-volt
battery discharge. Do not leave the vehicle with the power switch in ACCESSORY or ON mode for long periods of time when the hybrid system is not operating.
■Sounds and vibrations specific to a hybrid vehicle
 P. 88
■Electronic key battery depletion
 P. 141
■When the ambient temperature is low, such as during winter driving conditions
When starting the hybrid system, the flashing time of the “READY” indicator may be long. Leave the vehicle as it is until the “REA DY” indicator is steady on, as steady means
the vehicle is able to move.
■Conditions affecting operation
 P. 157
■Notes for the entry function
 P. 158
■If the hybrid system does not start
●Check that the shift lever is securely set in P. The hybrid system may not start if the shift lever is displaced out of P.
●The immobilizer system may not have been deactivated. ( P. 95)
Contact any authorized Lexus dealer or repairer, or another duly qualified and equipped professional.
■Steering lock
After turning the power switch off and openin g 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 over heating, 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 power switch. After about 10 seconds, the steering lock motor will resume functioning.
“Steering Lock active” 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.

3084-5. Using the driving support systems
RC300h_EE(OM24740E)
■Sounds and vibrations caused by the ABS, brake assist, TRC, VSC and hill-start assist control systems
Any of the following conditions may occur when the above systems are operating. None
of these indicates that a malfunction has occurred.
●Vibrations may be felt through the vehicle body and steering.
●A motor sound may be heard after the vehicle comes to a stop.
■ECB operating sound
ECB operating sound may be heard in the follow ing cases, but it does not indicate that a malfunction has occurred.
●Operating sound heard from the engine compartment when the brake pedal is oper-ated.
●Motor sound of the brake system heard from the front part of the vehicle when the
driver’s door is opened.
●Operating sound heard from the engine compartment when one or two minutes passed after the stop of the hybrid system.
■EPS operation sound
When the steering wheel is operated, a motor sound may be heard. This does not indi- cate a malfunction.
■Reactivation of the TRC/VSC systems
Even after the TRC/VSC systems have been turned off, turning the hybrid system off and then on again will automatically reactivate the TRC/VSC systems.
■Reactivation of the TRC system linked to vehicle speed
When only the TRC system is turned off, th e TRC system will turn on when vehicle speed increases. However, when both TRC and VSC 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 redu ced to prevent the system from overheating when there is frequent steering input over an extended period of time. The steeringwheel 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 after the brake pedal is released.

4446-1. Using the air conditioning system
RC300h_EE(OM24740E)
Turn the heated steering wheel on/off
The indicator light comes on when the heated steering wheel is operating.
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 uneven surface on the seat and do not sticksharp objects (needles, na ils, etc.) into the seat.
●To prevent 12-volt battery discharge, do not use the functions when the hybrid system is off.
Heated steering wheel

5878-2. Steps to take in an emergency
8
When trouble arises
RC300h_EE(OM24740E)
●The hybrid system coolant temperature gauge (P. 115) is in the red zone or
a loss of hybrid system power is experi enced. (For example, the vehicle speed
does not increase.)
●“Engine Coolant High Temperature” or “Hybrid System Overheat Output
Power is limited” is shown on the multi-information display.
●Steam comes out from under the hood.
■If the needle of the engine coolant temperature gauge enters the red zone
or “Engine Coolant High Temperature” 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 (radi-
ator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact any autho- rized Lexus dealer or repairer, oranother duly qualified and
equipped professional.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
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