2017 Lexus IS300h overheating

851-2. Hybrid system
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For safety and security
IS300h_EE(OM53D89E)
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 retailer or Lexus authoriz ed repairer, or any reliable repairer. Do not dispose of the battery yourself.
Unless the battery is properly collected, th e 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 any authorized Lexu s retailer or Lexus authorized repairer, or
any reliable repairer. 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 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 (traction battery), the battery may be damaged.
Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer.

1102. Instrument cluster
IS300h_EE(OM53D89E)
■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 the multi-information display.
( P. 119)
■Engine speed
On hybrid vehicles, engine speed is precisely 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.
■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 sp eeds (less than 20 km/h [12 mph])
●When the outside temperature has changed suddenly (at the entrance/exit of a garage, tunnel, etc.)
■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-info rmation display or the odometer/trip meter
screen (F SPORT models).
●Some pop-up displays can be set on/off. ( P. 119)
■Customization
The meter display can be customized on the multi-information display. (P. 119)
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. 636)

2074-1. Before driving
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Driving
IS300h_EE(OM53D89E)
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. Additiona lly, 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 not
securely hold the vehicle.
●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, 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.

2174-1. Before driving
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Driving
IS300h_EE(OM53D89E)
■Important points regarding stability
Vehicle movement resulting from unev en road surfaces and strong cross-
winds will affect handling. The vehicle ma y also be rocked by passing buses or
large trucks. Frequently check behind when moving alongside such vehicles.
As soon as such vehicle movement o ccurs, immediately start to decelerate
smoothly by slowly applying the brakes. Always steer the vehicle straight
ahead while braking.
■Passing other vehicles
Consider the total combined length of your vehicle and trailer and ensure that
the vehicle-to-vehicle distance is su fficient before executing lane changes.
■Transmission information
To maintain engine braking efficiency, when using engine braking when driv-
ing on a long steep downward grade, do not use the transmission in D. The
vehicle must be driven in gear shift position “4” in S mode. (P. 229)
■If the engine overheats
Towing a loaded trailer up a long, steep incline in temperatures exceeding
30 C (85F) may result in the engine overheating. If the engine coolant tem-
perature gauge indicates that the engine is overheating, turn the air condition-
ing off immediately, leave the road and stop the vehicle in a safe place.
( P. 636)
■When parking the vehicle
Always place wheel chocks under the wheels of both the vehicle and trailer.
Firmly set the parking brake an d shift the shift lever to P.

2224-2. Driving procedures
IS300h_EE(OM53D89E)
■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 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. After about 10 seconds, the steering
lock motor will resume functioning.
■When “Smart Entry & Start System Malfunction See Owner's Manual” is displayed on the multi-information display
The system may be malfunctioning. Have the vehicle inspected by any authorized Lexus
retailer or Lexus authoriz ed repairer, or any reliable repairer 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 vehicle, contact any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer immediately.
■If the hybrid system is malfunctioning
 P. 585
■If the electronic key battery is depleted
 P. 549
■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.
■If the smart entry & start system has been deactivated by a customized setting
 P. 628
“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.

3564-5. Using the driving support systems
IS300h_EE(OM53D89E)
■Automatic reactivation of TRC and VSC systems
After turning the TRC and VSC systems off, the systems will be automatically re-enabled in the following situations:
●When the power switch is turned off
●If only the TRC system is tu rned off, the TRC will turn on when vehicle speed increases If both the TRC and VSC syst ems are turned off, automatic re-enabling will not occur
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 emergency brake signal
When the following three conditions are me t, the emergency brake signal will operate:
●The emergency flashers are off
●Actual vehicle speed is over 55 km/h (35 mph)
●The brake pedal is depressed in a manner that cause the system to judge from the vehi-
cle deceleration that this is a sudden braking operation
■Automatic system cancelation of emergency brake signal
The emergency brake signal will turn of f in any of the following situations:
●The emergency flashers are turned on
●The brake pedal is released
●The system judges from the vehicle deceleration that is not a sudden braking operation

4796-2. Using the air conditioning system
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Interior features
IS300h_EE(OM53D89E)
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 vent ilators maintain good airflow by blow-
ing air from the seats.
WARNING
●Care should be taken to prev ent 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 no t use the functions when the hybrid system
is off.
Heated steering wheel

6368-2. Steps to take in an emergency
IS300h_EE(OM53D89E)
●The needle of the engine coolant temperature gauge (P. 105) enters the
red zone or a loss of hybrid system po wer 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 Ou tput Power” 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
Stop the vehicle in a safe place and tu rn 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 retailer or Lexus authorized repairer, or any reli-
able repairer.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
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