Page 520 of 628

5208-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
●Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
●Flat-looking tires or uneven tire wear
●Engine coolant temperature gauge needle continually points higher than nor-
mal.
●Changes in exhaust sound
●Excessive tire squeal when cornering
●Strange noises related to the suspension system
●Pinging or other noises related to the hybrid system
●Engine missing, stumbling or running roughly
●Appreciable loss of power
●Vehicle pulls heavily to one side when braking
●Vehicle pulls heavily to one side when driving on a level road
●Loss of brake effectiveness, spongy feeling, pedal almost touches the floor
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional as soon as possible.
Visible s ymp toms
Audible symptoms
Operational symptoms
Page 521 of 628

5218-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
If a warning light turns on or a warning buzzer
sounds
Calmly perform the following actions if any of the warning lights comes on or
flashes. If a light comes on or flashes, but then goes off, this does not necessar-
ily indicate a malfunction in the system. However, if this continues to occur,
have the vehicle inspected by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
Brake system warning light (warning buzzer)*1
Indicates that:
• The brake fluid level is low; or
• The brake system is malfunctioning
→ Immediately stop the vehicle in a safe place and contact any
authorized Lexus dealer or repairer, or another duly qualified
and equipped professional. Continuing to drive the vehicle may
be dangerous.
Brake system warning light
Indicates a malfunction in:
• The regenerative braking system; or
• The electronically controlled brake system
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
Charging system warning light
Indicates a malfunction in the vehicle’s charging system
→ Immediately stop the vehicle in a safe place and contact any
authorized Lexus dealer or repairer, or another duly qualified
and equipped professional.
Malfunction indicator lamp
Indicates a malfunction in:
• The hybrid system;
• The emission control system (if equipped);
• The electronic engine control system; or
• The electronic throttle control system
→ Have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional
immediately.
Page 531 of 628

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
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)
(Flashes)
Page 533 of 628

5338-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
(If equipped)
Indicates a malfunction in the LDA (Lane Departure
Alert) systemA buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
(If equipped)
Indicates a malfunction in the PCS (Pre-Crash Safety
system)
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 a malfunction in the BSM (Blind Spot Monitor)
system
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Indicates abnormal engine oil pressure
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.
Indicates a malfunction in:
• The regenerative brake system; or
• The electronically controlled brake 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.
Indicates that the Pop Up Hood system has operated
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 Pop Up Hood system
A buzzer also sounds.
→ Have the vehicle inspected by any authorized Lexus
dealer or repairer, or another duly qualified and
equipped professional.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)
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.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)
Page 536 of 628

5368-2. Steps to take in an emergency
IS300h_EE(OM53D56E)
Indicates that remaining fuel is approximately 10 L (2.6
gal., 2.2 Imp. gal.) or less
→Refuel the vehicle.
Indicates that the TRC (Tr action Control) system has
been deactivated
→ Tu r n t h e T R C o n . ( →P. 2 9 8 )
Indicates that the engine oil is scheduled to be changed.
(The indicator will not work properly unless the message
has been reset.)
→ Check the engine oil, and change if necessary.
After changing the engine oil, the message should
be reset.
Indicates that the engine oil should be changed. (After
the engine oil is changed and the message has been
reset.)
→Check and change the engine oil, and oil filter by
any authorized Lexus dealer or repairer, or another
duly qualified and equipped professional. After
changing the engine oil, the message should be
reset.
(If equipped)
Indicates that the Automatic High Beam switch is
pressed while the headlights are in low beam.
→ Turn the high beam on and press the Automatic
High Beam switch again.
(If equipped)
Indicates that, since the VSC (Vehicle Stability Control)
system was turned off, the pre-crash brake system oper-
ation is stopped
→Tu r n t h e V S C o n . ( →P. 2 9 8 )
(If equipped)
Indicates that the PCS (Pre-Crash Safety system) is not
currently functional because the grille cover or the sen-
sor is dirty
→ Check the grille cover and the sensor and clean
them if they are dirty.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)
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.
*
Interior
buzzerExteriorbuzzerWarning messageDetails/Actions
(Flashes)
(Flashes)
(Flashes)
Page 567 of 628
5678-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53D56E)
Open the exclusive jump starting
terminal cover.
Connect the jumper cables according to the following procedure:Connect a positive jumper cable clamp to the exclusive jump starting ter-
minal on your vehicle.
Connect the clamp on the other end of the positive cable to the positive (+)
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, station-
ary, 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 bat-
tery of your vehicle.
Open and close any of the doors of your vehicle with the power switch off.3
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