2015 Lexus GS450h engine overheat

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GS450h_OM_OM30F70U_(U)
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6-3. Do-it-yourself maintenanceDo-it-yourself service precautions................................ 423
Hood ............................................... 426
Positioning a floor jack..............427
Engine compartment ............... 429
12-volt battery ............................. 439
Tires.................................................. 443
Tire inflation pressure ............... 453
Wheels ........................................... 456
Air conditioning filter ............... 458
Electronic key battery.............. 460
Checking and replacing fuses.............................................. 462
Headlight aim ............................... 477
Light bulbs .....................................479
7-1. Essential information Emergency flashers .................. 494
If your vehicle has to be stopped in an emergency.... 495 7-2. Steps to take in an emergency
If your vehicle needs to be towed................................ 496
If you think something is wrong ................ 502
If a warning light turns on or a warning buzzer sounds..... 503
If a warning message is displayed ..................................513
If you have a flat tire ....................541
If the hybrid system will not start ............................... 554
If the shift lever cannot be shifted from P ..................... 556
If the parking brake cannot be released .................................557
If the electronic key does not operate properly ..................... 559
If the 12-volt battery is discharged............................. 562
If your vehicle overheats ......... 566
If the vehicle becomes stuck ............................................... 571
7When trouble arises

17Pictorial index
GS450h_OM_OM30F70U_(U)
Windshield wipers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 223
Precautions against winter season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 318
To prevent freezing (windshield wiper de-icer)
* . . . . . . . . . . . . . . . . . . . . . P. 361
Precautions against car wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 410
Fuel filler door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P . 230
Refueling method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 230
Fuel type/fuel tank capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 576
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 443
Tire size/inflation pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 582
Winter tires/tire chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 318
Checking/rotation/tire pressure warning system. . . . . . . . . . . . . . . . . . . . P. 443
Coping with flat tires. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 541
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 426
Opening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P . 426
Engine compartment cover. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 430
Engine oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 5 7 7
Coping with overheat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 566
Warning messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 520
Headlights/parking lights/daytime running ligh ts . . . . . . . . . . . . . . . . . . . P. 217
Fog lights
* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 222
Turn signal lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 209
Tail lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 217
Stop lights
Brake Hold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P . 214
License plate lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 21 7
Back-up lights
Shifting the shift lever to R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 203
Side marker lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 217
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Light bulbs of the exterior lights for driving
( R e p l a c i n g m e t h o d : P. 4 7 9 , Wa t t s : P. 5 8 3 )
*: If equipped
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GS450h_OM_OM30F70U_(U)
952. Instrument cluster
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Instrument cluster
■ECO lamp and SPORT lamp
●When sport mode is selected, SPORT lamp (red) will illuminate.
●When all of the following conditions are satisfied and Eco-friendly driving, ECO
lamp (blue) will illuminate. (ECO lamp will become brighter the more Eco-friendly
driving you perform. Also, while the vehicle is stopped or the acceleration exceeds
Zone of Eco driving, ECO lamp turns off. [P. 9 4 ] H o w e v e r, w h e n E c o d r i v e
mode is selected, while the vehicle is stopped or the acceleration exceeds Zone of
Eco driving, ECO lamp does not turn off.):
• Driving with the shift lever in D
• Paddle shift switch is not operated.
• Either normal mode or Eco drive mode is selected.
• The vehicle speed is approximately 80 mph (130 km/h) or below.
■Tachometer
Hybrid System Indicator switches to the ta chometer when driving mode is in sport
mode.
■Engine speed
On hybrid vehicles, engine speed is precis ely controlled in order to help improve
fuel efficiency and reduce exhaust emissions etc.
There are times when the engine speed that is displayed may differ even when vehi-
cle operation and driving conditions are the same.
■Customization
Settings (e.g. on/off operatio n of ECO lamp) can be changed.
(Customizable features: P. 5 9 9 )
NOTICE
■To prevent damage to the engine and its components
●Do not let the indicator needle of the tachometer enter the red zone, which indi-
cates the maximum engine speed.
●The engine may be overheating if the engine coolant temperature gauge is in the
red zone (H). In this case, immediately stop the vehicle in a safe place, and check
the engine after it has cooled completely. ( P. 566)

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GS450h_OM_OM30F70U_(U)
4-1. Before driving
CAUTION
Observe the following precautions.
Failure to do so may result in death or serious injury.
■When driving the vehicle
●During normal driving, do not turn off the hybrid system. Turning the hybrid sys-
tem off while driving will not cause loss of steering or braking control, however,
power assist to the steering will be lost. This will make it more difficult to steer
smoothly, so you should pull over and stop th e vehicle as soon as it is safe to do so.
In the event of an emergency, such as if it becomes impossible to stop the vehicle
in the normal way:  P. 4 9 5
●Use engine braking (downshift) to maintain a safe speed when driving down a
steep hill.
Using the brakes continuously may cause the brakes to overheat and lose effec-
tiveness. ( P. 2 0 3 )
●Do not adjust the positions of the steering wheel, the seat, or the inside or outside
rear view mirrors while driving.
Doing so may result in a loss of vehicle control.
●Always check that all passengers’ arms, heads or other parts of their body are not
outside the vehicle.
●Do not drive in excess of the speed limit. Even if the legal speed limit permits it, do
not drive over 85 mph (140 km/h) unless your vehicle has high-speed capability
tires. Driving over 85 mph (140 km/h) may result in tire failure, loss of control and
possible injury. Be sure to consult a tire dealer to determine whether the tires on
your vehicle are high-speed capability tires or not before driving at such speeds.

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GS450h_OM_OM30F70U_(U)
4-1. Before driving
CAUTION
■If you hear a squealing or scraping noise (brake pad wear limit indicators)
Have the brake pads checked and replaced by your Lexus dealer as soon as possi-
ble.
Rotor damage may result if the pads are not replaced when needed.
Front brakes only: Moderate levels of brake pad and disc wear allow enhanced
front braking power. As a result, the discs may wear more quickly than conven-
tional brake discs. Therefore, when replacing the brake pads, Lexus recommends
that you also have the thickness of the discs measured.
It is dangerous to drive the vehicle when the wear limits of the brake pads and/or
those of the brake discs are exceeded.
■When the vehicle is stopped
●Do not depress the accelerator pedal unnecessarily.
If the vehicle is in any gear other than P or N, the vehicle may accelerate suddenly
and unexpectedly, causing an accident.
●In order to prevent accidents due to the vehicle rolling away, always keep
depressing the brake pedal while the “READY” indicator is on, and apply the
parking brake as necessary.
●If the vehicle is stopped on an incline, in order to prevent accidents caused by the
vehicle rolling forward or backward, always depress the brake pedal and securely
apply the parking brake as needed.
●Avoid revving or racing the engine.
Running the engine at high speed whil e the vehicle is stopped may cause the
exhaust system to overheat, which could result in a fire if combustible material is
nearby.

5287-2. Steps to take in an emergency
GS450h_OM_OM30F70U_(U)
Indicates that the hybrid
system output is limited
because the engine oil is
overheatedDrive the vehicle at a safe
speed until the warning
message disappears.
Indicates that the vehicle
is unable to drive over
65 mph (110 km/h) until
the transmission warms
up
Wait until the transmis-
sion warms up.
Indicates that remaining
fuel is approximately 2.6
gal. (10.0 L, 2.2 Imp.gal.)
or less
Refuel the vehicle.
Indicates that the power
switch is turned off or
turned to ACCESSORY
mode and the driver’s
door is opened while the
lights are turned on
Tu r n t h e l i g h t s o f f .
Indicates that the driver’s
door was opened with the
shift position in any posi-
tion other than P
Shift the shift position to P.
Wa r n i n g m e s s a g eDetailsCorrection procedure
(If equipped)
(Flashes)
(Flashes)

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GS450h_OM_OM30F70U_(U)
7-2. Steps to take in an emergency
If your vehicle overheats
■If the needle of the engine coolant temperature gauge enters the red
zone
Stop the vehicle in a safe place an d 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 cooling system for leaks.
Radiator
Cooling fans
If a large amount of coolant
leaks, immediately contact your
Lexus dealer.
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge ( P. 91) enters
the red zone or a loss of hybrid system power is experienced. (For
example, the vehicle speed does not increase.)
●“Hybrid System Overheat” ( P. 527) is shown on the multi-informa-
tion display.
●Steam comes out from under the hood.
Correction procedures
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636Alphabetical index
GS450h_OM_OM30F70U_(U)
Child restraint system............................ 57Booster seats, definition .................... 57
Booster seats, installation.................. 67
Convertible seats, definition ............ 57
Convertible seats, installation ......... 64
Front passenger occupant classification system ......................... 49
Infant seats, definition .......................... 57
Infant seats, installation ....................... 64
Installing CRS with LATCH anchors ..................... 62
Installing CRS with seat belts .......... 64
Installing CRS with top tether strap .........................68
Child safety ................................................ 56 12-volt battery precautions ............................. 441, 565
Airbag precautions ................................41
Child restraint system ......................... 57
How your child should wear the seat belt ................................. 33, 35
Installing child restraints.......................61
Moon roof precautions.....................174
Power window lock switch .............167
Power window precautions .......... 170
Rear door child-protectors ........... 140
Removed electronic key battery precautions................ 461
Seat belt comfort guide ..................... 33
Seat belt extender precautions ...... 37
Seat belt precautions ..........................60
Seat heater precautions................. 384
Trunk precautions............................... 146 Child-protectors .................................... 140
Cleaning ........................................ 408, 412
Aluminum wheels ..............................409
Exterior .................................................. 408
Interior ....................................................... 412
Seat belts.................................................. 413
Clock..........................................................376
Coat hooks ............................................. 390
Condenser.............................................. 436
Console box ........................................... 369
Console box light ................................. 369
Consumption screen ..............................114
Coolant .....................................................434 Capacity................................................. 579
Checking ............................................... 434
Preparing and checking before winter..................................................... 318
Cooling system ......................................434 Engine overheating ..........................566
Hybrid system overheating ..........566
Cruise control Cruise control ..................................... 235
Dynamic radar cruise control ..... 239
Dynamic radar cruise control with full-speed range ................... 254
Cup holders............................................ 370
Curtain shield airbags ............................39
Customizable features ...................... 599