2015 Lexus GS300h coolant temperature

4927-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
Indicates a malfunction in:•The ABS; or
• The brake assist 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 engine coolant temperature is too high
A buzzer also sounds.
→ P. 5 5 6
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.
Wa r n i n g m e s s a g eDetails/Actions

5567-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
If your vehicle overheats
●The needle of the engine coolant temperature gauge ( →P. 104) enters the
red zone or a loss of hybrid system power is experienced. (For example, the
vehicle speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” or
“Hybrid System Overheated Reduced Output Power” ( →P. 482) 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 Temp High Stop in a Safe Place See Owner’s Manual” 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
cooling system for leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact any autho-
rized Lexus dealer or repairer, or
another duly qualified and
equipped professional.
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2

5587-2. Steps to take in an emergency
GS450h_300h_OM_OM30F00E_(EE)
Start the hybrid system and turn the air conditioning system on to check
that the radiator cooling fans operate and to check for coolant leaks from
the radiator or hoses.
The fans operate when the air conditioning system is turned on immediately after a
cold start. Confirm that the fans are 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 fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the hybrid system immediately and contact any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional.
If the fans are operating:
Have the vehicle inspected at the nearest any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
■If “Hybrid System Overheated Reduced Output Power” is shown on the
multi-information displayStop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has cooled down, inspect the hoses and radiator
core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact any autho-
rized Lexus dealer or repairer, or
another duly qualified and
equipped professional.
6
7
1
2
3
1
2

5617-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F00E_(EE)
WA R N I N G
■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 indicator on the power
switch and the “READY” indicator are off.
When the hybrid system is 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 fan, which may lead to fingers or clothing
(especially a tie, a scarf or a muffler) ge tting caught, resulting in serious injury.
●Do not loosen the coolant inlet cap or the
coolant reservoir caps while the hybrid sys-
tem and radiator are hot.
High temperature steam or coolant could
spray out.XGS450h
XGS300h

607Alphabetical index
GS450h_300h_OM_OM30F00E_(EE)
Engine coolant temperature gauge....................................................... 105
Engine oil.................................................. 422 Capacity .................................................570
Checking ............................................... 422
Oil level warning message ........... 482
Oil pressure warning message..............................................482
Preparing and checking before winter ....................................354
Engine switch ...........................................217 Auto power off function ...................219
Changing the power switch modes ................................................... 218
If your vehicle has to be stopped in an emergency..........469
Starting the hybrid system............... 217
EPS (Electric Power Steering)........345
Function ..................................................345
Warning light ....................................... 477
Warning message.............................482
EV drive mode ....................................... 222
First-aid kit storage net.......................395
Flat tire
Vehicles with spare tire ....................517
Vehicles without spare tire ...........528
Floor mats ................................................... 34
Fluid Brake........................................................ 574
Hybrid transmission ......................... 573
Washer ................................................... 427 Fog lights .................................................. 249
Replacing light bulbs ....................... 465
Switch ...................................................... 249
Follow me home system .................... 237
Footwell light .......................................... 386
Front air conditioning system .......... 366
Front fog lights ....................................... 249 Replacing light bulbs ....................... 465
Switch ...................................................... 249
Wattage ................................................. 465
Front personal lights............................ 387
Front position lights ............................. 236 Light switch........................................... 236
Replacing light bulbs ....................... 465
Welcome light illumination control ...................................................140
Front seats ................................................. 175 Adjustment ............................................. 175
Cleaning .................................................. 410
Correct driving posture.................... 36
Driving position memory ................ 178
Head restraints .....................................183
Power easy access system............. 178
Seat heaters.......................................... 382
Seat position memory ....................... 178
Seat ventilators ................................... 382
Front turn signal lights ........................ 230 Replacing light bulbs ...........459, 465
Turn signal lever................................. 230
Wattage ................................................. 578
F
*: Refer to the “NAVIGATION AND MULTIMEDIA SYSTEM OWNER’S MANUAL”.