4487-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
The meanings of each caution symbol on the top of the 12-volt battery are
as follows:
Before recharging
When recharging, the 12-volt battery produces hydrogen gas which is flammable
and explosive. Therefore, observe the following precautions before recharging:
If recharging with the 12-volt battery installed on the vehicle, be sure to discon-
nect the ground cable.
Make sure the power switch on the charger is off when connecting and discon-
necting the charger cables to the 12-volt battery.
After recharging/reconnecting the 12-volt battery
The hybrid system may not start. Follow the procedure below to initialize the
system.
Shift the shift lever to P.
Open and close any of the doors.
Restart the hybrid system.
Unlocking the doors using the smart entry & start system may not be possible
immediately after reconnecting the 12-volt battery. If this happens, use the
wireless remote control or the mechanical key to lock/unlock the doors.
Start the hybrid system with the power switch in ACCESSORY mode. The
hybrid system may not start with the power switch turned off. However, the
hybrid system will operate normally from the second attempt.
The power switch mode is recorded by the vehicle. If the 12-volt battery is
reconnected, the vehicle will return the power switch mode to the status it was
in before the 12-volt battery was disconnected. Make sure to turn off the power
switch before disconnecting the 12-volt battery. Take extra care when connect-
ing the 12-volt battery if the power switch mode prior to the 12-volt battery
being disconnected is unknown.
If the system will not start even after multiple attempts at all the methods above,
contact any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
Caution symbols
No smoking, no naked
flames, no sparks12-volt battery acid
Shield eyesNote operating instruc-
tions
Keep away from childrenExplosive gas
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4587-3. Do-it-yourself maintenance
IS300h_EE(OM53B95E)
CAUTION
When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drivetrain as well as danger-
ous handling characteristics, which may lead to an accident resulting in death
or serious injury.
Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear.
Do not use tire sizes other than those recommended by Lexus.
Do not mix differently constructed tires (radial, bias-belted or bias-ply tires).
Do not mix summer, all season and snow tires.
Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously.
Vehicles with an emergency tire puncture repair kit: Do not tow anything if a
tire that has been repaired using the emergency tire puncture repair kit is
installed. The load on the tire may cause unexpected damage to the tire.
When initializing the tire pressure warning system
Do not operate the tire pressure warning reset switch without first adjusting the
tire inflation pressure to the specified level. Otherwise, the tire pressure warn-
ing light may not come on even if the tire inflation pressure is low, or it may
come on when the tire inflation pressure is actually normal.
5128-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute
when the power switch is turned to ON mode, have it checked by any authorized
Lexus dealer or repairer, or another duly qualified and equipped professional.
Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or
audio sound.
CAUTION
If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediately and contact any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional. The
vehicle will become extremely unstable during braking, and the ABS system
may fail, which could cause an accident resulting in death or serious injury.
When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
If the steering wheel becomes heavier than usual when operating, hold firmly
and operate using more force than usual.
If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause a
loss of vehicle control and result in death or serious injury.
Vehicles with an emergency tire puncture repair kit
Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation
pressure immediately.
If the tire pressure warning light comes on even after tire inflation pressure
adjustment, it is probable that you have a flat tire. Check the tires. If a tire is
flat, repair the flat tire by using emergency tire puncture repair kit.
Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
Vehicles with run-flat tires
Decelerate to the lowest appropriate speed as soon as possible. Do not drive
over 60 km/h (37 mph).
Check and adjust the tire inflation pressure immediately.
If the tire pressure warning light comes on even after tire inflation pressure
adjustment, it is probable that you have a flat tire. Have the tire replaced by
the nearest authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.
5248-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
*1: Refer to the separate “Lexus Service Booklet” or “Lexus Warranty Booklet”
for the maintenance interval applicable to your vehicle.
*2: For the EV drive mode operating conditions: P. 214
Indicates that the EV drive mode is not available*2
The reason the EV drive mode is not available
(the vehicle is idling, hybrid battery [traction bat-
tery] charge is low, speed is higher than the EV
drive mode operating speed range, accelerator
pedal is depressed too much) may be displayed.
A buzzer also sounds.
Use the EV drive mode when it becomes avail-
able.
Indicates that the EV drive mode has been automat-
ically canceled
*2
The reason the EV drive mode is not available
(the hybrid battery [traction battery] charge is
low, speed is higher than the EV drive mode
operating speed range, accelerator pedal is
depressed too much) may be displayed.
A buzzer also sounds.
Drive the vehicle for a while.
Warning messageDetails/Actions
(Except F
SPORT mod-
els)(F SPORT
models)
(Flashes) (Flashes)
5258-2. Steps to take in an emergency
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When trouble arises
IS300h_EE(OM53B95E)
Warning messages
The warning message illustrations used are intended as examples, and may differ
from the image that is actually displayed on the multi-information display.
Warning message in radar cruise mode (if equipped)
In the following situations, the warning message may not be displayed even if
vehicle-to-vehicle distance decreases:
When your vehicle and the vehicle ahead are traveling at the same speed or the
vehicle ahead is traveling more quickly than your vehicle
When the vehicle ahead is traveling at a very low speed
Immediately after cruise control speed is set
At the instant the accelerator pedal is depressed
The LDA (Lane Departure Alert) lane departure warning function (if equipped)
In the following situations, the warning message will not be displayed even if a
lane line is crossed.
When the vehicle speed deviates from the operating range of the LDA system
functions
When the lane lines cannot be recognized
After changing the engine oil (if equipped)
Make sure to reset the oil change system. (P. 442)
Warning buzzer
P. 512
5478-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
One of the following may be the cause of the problem:
One or both of the 12-volt battery terminals may be disconnected.
The 12-volt battery may be discharged. (P. 551)
Contact any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional if the problem cannot be repaired, or if repair proce-
dures are unknown.
When the hybrid system does not start, the following steps can be used as
an interim measure to start the hybrid system if the power switch is func-
tioning normally:
Set the parking brake.
Shift the shift lever to P.
Turn the power switch to ACCESSORY mode.
Press and hold the power switch for about 15 seconds while depressing
the brake pedal firmly.
Even if the hybrid system can be started using the above steps, the system
may be malfunctioning. Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly qualified and equipped profes-
sional.
The interior lights and headlights do not turn on, or the horn does
not sound.
Emergency start function
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5508-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
Ensure that the shift lever is in P and depress the brake pedal.
Touch the Lexus emblem side of
the electronic key to the power
switch.
When the electronic key is detected,
a buzzer sounds and the power
switch will turn to ON mode.
When the smart entry & start system
is deactivated in customization set-
ting, the power switch will turn to
ACCESSORY mode.
Firmly depress the brake pedal and check that is shown on the
multi-information display.
Press the power switch.
In the event that the hybrid system still cannot be started, contact any
authorized Lexus dealer or repairer, or another duly qualified and
equipped professional.
Stopping the hybrid system
Shift the shift lever to P and press the power switch as you normally do when
stopping the hybrid system.
Replacing the key battery
As the above procedure is a temporary measure, it is recommended that the elec-
tronic key battery be replaced immediately when the battery is depleted. (P.
472)
Alarm (if equipped)
Using the mechanical key to lock the doors will not set the alarm system.
If a door is unlocked using the mechanical key when the alarm system is set, the
alarm may be triggered.
Changing power switch modes
Release the brake pedal and press the power switch in step above.
The hybrid system does not start and modes will be changed each time the switch
is pressed. (P. 210)
When the electronic key does not work properly
Make sure that the smart entry & start system has not been deactivated in the
customization setting. If it is off, turn the function on.
(Customizable features P. 575)
Check if battery-saving mode is set. If it is set, cancel the function. (P. 150)
Starting the hybrid system
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5528-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
Connect the jumper cables according to the following procedure:
Connect a positive jumper cable clamp to the exclusive jump start-
ing terminal on your vehicle.
Connect the clamp on the other end of the positive cable to the posi-
tive (+) battery terminal on the second vehicle.
Connect a negative cable clamp to the negative (-) battery terminal
on the second vehicle.
Connect the clamp at the other end of the negative cable to a solid,
stationary, unpainted metallic point away from the exclusive jump
starting terminal and any moving parts, as shown in the illustration.
Start the engine of the second vehicle. Increase the engine speed
slightly and maintain at that level for approximately 5 minutes to
recharge the 12-volt battery of your vehicle.
Open and close any of the doors of your vehicle with the power switch
off.
Maintain the engine speed of the second vehicle and start the hybrid
system of your vehicle by turning the power switch to ON mode.
Make sure the “READY” indicator comes on. If the indicator does not
come on, contact any authorized Lexus dealer or repairer, or another
duly qualified and equipped professional.3
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