Page 524 of 628

5248-2. Steps to take in an emergency
IS300h_EE(OM53D56E)*
1: Parking brake engaged warning buzzer:
→ P. 5 3 1
*2: Open door warning buzzer:
→ P. 5 2 9
*3: Seat belt warning buzzer:
The seat belt warning buzzer sounds to alert the driver, front passenger and rear pas-
sengers that his or her seat belt is not fastened. The buzzer sounds for 30 seconds
after the vehicle reaches a speed of 20 km/h (12 mph). Then, if the seat belt is still
unfastened, the buzzer will sound in a different tone for 90 more seconds.
■Passenger detection sensor, seat belt reminder and warning buzzer
●If luggage is placed on a passenger seat, the passenger detection sensor may cause the
warning light to flash and the warning buzzer to sound even if a passenger is not sitting
in the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the warn-
ing light may not operate properly.
■If the malfunction indicator lamp comes on while driving
The malfunction indicator lamp will come on if the fuel tank becomes completely empty.
If the fuel tank is empty, refuel the vehicle immediately. The malfunction indicator lamp
will go off after several trips.
If the malfunction indicator lamp does not go off, contact any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional as soon as possible.
■Electric power steering system warning light (warning buzzer)
When the 12-volt battery charge becomes insu fficient or the voltage temporarily drops,
the electric power steering system warning light may come on and the warning buzzer
may sound.
■When the tire pressure warning light comes on
Carry out the following procedure after the tire temperature has lowered sufficiently.
●Check the tire inflation pressure and adjust to the appropriate level.
●If the warning light does not go out even after several minutes, check that the tire infla-
tion pressure is at the specifie d level and carry out initialization.
The warning light may come on again if the above operations are conducted without first
allowing the tire temperature to lower sufficiently.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air
leaks and tire inflation pressure changes caused by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (after a few minutes).
■Conditions that the tire pressure warning system may not function properly
→ P. 4 7 1
Page 530 of 628

5308-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
(If equipped)
Indicates a malfunction in the Lexus parking assists-sen-
sor
The assist-sensors flash.
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
(If equipped)
Indicates that a Lexus parking assist-sensor is dirty or
covered with ice
A buzzer also sounds.
→ Clean the sensor.
Indicates that the accelerator pedal is depressed while
the shift position is in N
A buzzer also sounds.
→ Release the accelerator pedal and shift the shift
lever to D, S or R.
Indicates that the accelerator pedal is depressed to stop
the vehicle on an upward slope, etc.
A buzzer also sounds.
→ Release the accelerator pedal and depress the
brake pedal.
Indicates that the hybrid battery (traction battery) power
has dropped because a long period of time has elapsed
after shifting the shift lever to N
A buzzer also sounds.
→ Restart the hybrid system when starting the vehicle.
Indicates a malfunction in the hybrid system
A buzzer also sounds.
→ Immediately stop the vehicle in a safe place and
contact any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
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5318-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
Indicates that the hybrid battery (traction battery) is lowA buzzer also sounds.
→ When stopping the vehicle for a long period of time,
shift the shift lever to P. The hybrid battery (traction
battery) cannot be charged with the shift lever in N.
Indicates a malfunction in the EPS (Electric Power Steer-
ing) system
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Indicates that the vehicle is being driven at 5 km/h (3
mph) or more with the parking brake still engaged
A buzzer also sounds.
→ Release the parking brake.
Indicates a malfunction in:
• The SRS airbag system; or
• The seat belt pretensioner system
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Indicates a malfunction in:
•The ABS; or
• The brake assist system
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Indicates that the engine coolant temperature is too high
A buzzer also sounds.
→ P. 5 7 1
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Page 535 of 628

5358-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
Indicates a malfunction in the brake override systemA buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Indicates that engine oil level is low
A buzzer also sounds.
→ Check the level of engine oil, and add if necessary.
Indicates that the hybrid system has overheated
This message may be displayed when driving under
severe operating conditions. (For example, when driv-
ing up a long steep hill.)
A buzzer also sounds.
→ Stop and check. ( →P. 5 7 1 )
Indicates a malfunction in:
• The automatic headlight leveling system; or
• The Automatic High Beam system (if equipped)
• The LED headlight system (if equipped)
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Indicates that the accelerator and brake pedal are being
depressed simultaneously
→Release the accelerator or brake pedal.
Maintenance of the hybrid battery (traction battery)
cooling component is required
The filter may be clogged, the air intake vent may be
blocked or there may be a gap in the duct
→ Have maintenance performed on the hybrid battery
(traction battery) cooling component by any autho-
rized Lexus dealer or repairer, or another duly qual-
ified and equipped professional.
Indicates that the washer fluid level is low
→Add washer fluid.
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Page 537 of 628
5378-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
Indicates that operation of large electricity consuming
systems such as the air conditioning system are sus-
pended
→ Stop using unnecessary electric components to
reduce electricity consumpt ion. Wait a while until
the electric power supply is restored.
(If equipped)
Indicates that the LDA (Lane Departure Alert) system
cannot be used because the vehicle speed is lower than
approximately 50 km/h (32 mph)
→ Drive the vehicle at 50 km/h (32 mph) or higher.
Indicates that the EV drive mode is not available*
The reason the EV drive mode is not available (the
vehicle is idling, 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.
→ Use the EV drive mode when it becomes available.
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Page 538 of 628
5388-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
*: For the EV drive mode operating conditions: →P. 2 1 7
Indicates that the EV drive mode has been automatically
canceled
*
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.
Wa r n i n g m e s s a g eDetails/Actions
(Except F
SPORT models) (F SPORT
models)
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Page 542 of 628

5428-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
Once
The electronic key has a low battery.
→Replace the electronic key bat-
tery. ( →P. 488)
Once
The steering lock could not be
released within 3 seconds of the
power switch being pressed.
→ Press the power switch while
depressing the brake pedal and
moving the steering wheel left
and right.
Once
Indicates a malfunction in the smart
entry & start system
→Have the vehicle inspected by
any authorized Lexus dealer or
repairer, or another duly quali-
fied and equipped professional.
Once
• When the doors were unlocked
with the mechanical key and then
the power switch was pressed, the
electronic key could not be
detected in the vehicle.
• The electronic key could not be detected in the vehicle even after
the power switch was pressed two
consecutive times.
→ Touch the electronic key to the
power switch while depressing
the brake pedal.
Once
During a hybrid system starting pro-
cedure in the event that the elec-
tronic key was not functioning
properly ( →P. 5 6 4 ) , t h e p o w e r
switch was touched with the elec-
tronic key.
→ Press the power switch within 10
seconds of the buzzer sounding.
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Page 543 of 628

5438-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
Indicates that:
• With the power switch off, thedoors were unlocked and then the
driver’s door was opened and
closed;
• The power switch was turned to ACCESSORY mode without
starting the hybrid system; or
• The shift lever was shifted to P from another position with the
power switch in ON mode.
→ Press the power switch while
depressing the brake pedal.
Once
The power switch has been turned
off with the shift lever in a position
other than P.
→Shift the shift lever to P.
Once
After the power switch has been
turned off with the shift lever in a
position other than P, the shift lever
has been shifted to P.
→Tu r n t h e p o w e r s w i t c h o f f .
Power was turned off due to the
automatic power off function.
→Next time when starting the
hybrid system, increase the
engine speed slightly and main-
tain that level for approximately
5 minutes to recharge the 12-
volt battery.
Con-
tinuous
Indicates that the hybrid system was
stopped in an emergency while driv-
ing
→To restart the hybrid system,
shift the shift lever to N and turn
the power switch to ON mode.
*
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