Page 532 of 628

5188-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
Indicates a malfunction in the EPS (Electric Power
Steering) system
A buzzer also sounds.
Have the vehicle inspected by any authorized
Lexus dealer or repairer, or another duly quali-
fied 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 quali-
fied 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 quali-
fied and equipped professional.
Indicates that the engine coolant temperature is too
high
A buzzer also sounds.
P. 5 5 6
(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 570 of 628

5568-2. Steps to take in an emergency
IS300h_EE(OM53B95E)
The needle of the engine coolant temperature gauge (P. 110) enters
the red zone or a loss of hybrid system power is experienced. (For
example, the vehicle speed does not increase.)
“Hybrid System Overheat” 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 turn off the air conditioning sys-
tem, 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 (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact any
authorized Lexus dealer or
repairer, or another duly quali-
fied and equipped professional.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2
Page 571 of 628

5578-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL”
“LOW”
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fan operates and to check for coolant
leaks from the radiator or hoses.
The fan operates when the air conditioning system is turned on immedi-
ately after a cold start. Confirm that the fan is operating by checking the fan
sound and air flow. If it is difficult to check these, turn the air conditioning
system on and off repeatedly.
(The fan may not operate in freezing temperatures.)
If the fan is not operating:
Stop the hybrid system immediately and contact any authorized
Lexus dealer or repairer, or another duly qualified and equipped pro-
fessional.
If the fan is operating:
Have the vehicle inspected at the nearest authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
If “Hybrid System Overheat” is shown on the multi-information dis-
play
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
4
1
2
3
5
6
7
1
2
Page 573 of 628

5598-2. Steps to take in an emergency
8
When trouble arises
IS300h_EE(OM53B95E)
CAUTION
When inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartment may be very hot.
After the hybrid system has been turned off, check that the “READY” indica-
tor is off.
When the hybrid system operating, the gasoline engine may automatically
start, or the cooling fan may suddenly operate even if the gasoline engine
stops. Do not touch or approach rotating parts such as the belt and fan, which
may lead to fingers or clothing (especially a tie, a scarf or a muffler) getting
caught, resulting in serious injury.
NOTICE
When adding engine/power control unit coolant
Add coolant slowly after the hybrid system has cooled down sufficiently. Add-
ing cool coolant to a hot hybrid system too quickly can cause damage to the
hybrid system.
To prevent damage to the cooling system
Observe the following precautions:
Avoid contaminating the coolant with foreign matter (such as sand or dust
etc.).
When using coolant additives, use genuine Toyota products or equivalent.
Do not loosen the coolant reservoir caps
or water filler cap while the hybrid sys-
tem and radiator are hot.
High temperature steam or coolant could
spray out.
Page 613 of 628

597Alphabetical index
IS300h_EE(OM53B95E)
If you have a flat tire ....531, 545
If you think something
is wrong ..............................506
If your vehicle becomes stuck ....
560
If your vehicle has to be
stopped in an emergency ....499
If your vehicle needs to
be towed .............................500
If your vehicle overheats ......556
Emergency brake signal ............294
Emergency flashers ...................498
Emergency tire puncture
repair kit ..................................531
Energy monitor..........................122
Engine .......................................564
Accessory mode....................210
Compartment ........................439
Engine switch .......................209
Hood .....................................437
How to start the hybrid
system.................................209
Identification number ...........563
Ignition switch
(power switch)....................209
Overheating ..........................556
Power switch ........................209Engine coolant .......................... 444
Capacity ............................... 567
Checking .............................. 444
Preparing and checking
before winter ..................... 311
Engine coolant temperature
gauge ...................................... 110
Engine oil ................................. 440
Capacity ............................... 565
Checking .............................. 440
Preparing and checking
before winter ..................... 311
Engine switch ........................... 209
EPS (Electric Power Steering) . 293
Function ............................... 293
Warning light ....................... 508
EV drive mode.......................... 214
EV indicator ............................. 118