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5368-2. Steps to take in an emergency
RC300h_EE(OM24740E)
●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 continually points higher than normal.
●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 fe eling, 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 an d equipped professional as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms
Page 537 of 640

5378-2. Steps to take in an emergency
8
When trouble arises
RC300h_EE(OM24740E)
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 an d equipped professional.
Warning light and warning buzzer list
Warning lightWarning light/Details/Actions
Brake system warning light (warning buzzer) Indicates that:
• The brake fluid level is low; or • The brake system is malfunctioningThis light also comes on when the parking brake is not released. If
the light turns off after the parking brake is fully released the system is operating normally. 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 maybe dangerous.
Brake system warning lightIndicates 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 lampIndicates 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 547 of 640
5478-2. Steps to take in an emergency
8
When trouble arises
RC300h_EE(OM24740E)
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. 587
(If equipped)
Indicates that the radar sensor is dirty or covered with ice
A buzzer also sounds. Clean the sensor.
Warning messageDetails/Actions
(Flashes)
Page 549 of 640

5498-2. Steps to take in an emergency
8
When trouble arises
RC300h_EE(OM24740E)
(If equipped)
Indicates a malfunction in the LDA (Lane Departure
Alert) 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 PCS (Pre-Crash Safetysystem)A buzzer also sounds.
Have the vehicle inspected by any authorized Lexus dealer or repairer, or another duly qualified andequipped professional immediately.
(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.
Warning messageDetails/Actions
(Flashes)
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5518-2. Steps to take in an emergency
8
When trouble arises
RC300h_EE(OM24740E)
Indicates that the windows are not fully closed (with the
power switch off, and the driver’s door open) A buzzer also sounds. Close all the windows.
(If equipped)
Indicates that the windows and the moon roof are not fully closed (with the power switch off, and the driver’s
door open) A buzzer also sounds. Close all the windows and the moon roof.
Indicates a malfunction in the brake override 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 engine oil level is low This message may appear if the vehicle is stopped on a
slope. Move the vehicle to a level surface and check to see if the message disappears.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 undersevere operating conditions. (For example, when driv-
ing up a long steep hill.) A buzzer also sounds.
Stop and check. (P. 587)
Warning messageDetails/Actions
(Flashes)
(Flashes)
Page 554 of 640

5548-2. Steps to take in an emergency
RC300h_EE(OM24740E)
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. (Afterthe 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 bereset.
(If equipped)
Indicates that the Automatic High Beam switch ispressed 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 Operation of the pre-crash brake assist is alsostopped.
Turn the VSC on. (P. 307)
(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.
Warning messageDetails/Actions
(Flashes)
Page 583 of 640

5838-2. Steps to take in an emergency
8
When trouble arises
RC300h_EE(OM24740E)
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.
Maintain the engine speed of the seco nd vehicle and start the hybrid system
of your vehicle by turning the power switch to ON mode.
3
4
1
2
3
4
5
6
7
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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
1
2
3
1
2