2015 Lexus GS450h coolant temperature

92
GS450h_OM_OM30E26U_(U)
2. Instrument cluster
Engine coolant temperature gauge
Displays the engine coolant temperature
Hybrid System Indicator
Displays hybrid system output or regeneration level ( P. 9 4 )
ECO lamp and SPORT lamp
Changes colors or brightness according to driving mode or way of driving
( P. 9 5 )
Multi-information display
Presents the driver with a variety of driving-related data ( P. 9 6 )
Speedometer
Displays the vehicle speed
Fuel gauge
Displays the quantity of fuel remaining in the tank
Shift position and shift range
Displays the selected shift position or selected shift range ( P. 2 0 3 )
Odometer and trip meter display
Odometer:
Displays the total distance the vehicle has been driven
Tr i p m e t e r :
Displays the distance the vehicle has been driven since the meter was last reset.
Trip meters “A” and “B” can be used to record and display different distances inde-
pendently.
Tachometer
Displays the engine speed in revolutions per minute
1
2
3
4
5
6
7
8
9

GS450h_OM_OM30E26U_(U)
952. Instrument cluster
2
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)

319
GS450h_OM_OM30E26U_(U)4-6. Driving tips
4
Driving
Winter driving tips
●Use fluids that are appropriate to the prevailing outside temperatures. • Engine oil
• Engine/power control unit coolant
• Washer fluid
●Have a service technician inspect th e condition of the 12-volt battery.
●Have the vehicle fitted with four sno w tires or purchase a set of tire
chains for the rear tires.
*
Ensure that all tires are the specified size and brand, and that chains match the
size of the tires.
*: Tire chains cannot be mounted on vehicles with front and rear tires of differing
sizes and vehicles with LDH and 19-inch tires.
Carry out the necessary preparati ons and inspections before driving
the vehicle in winter. Always drive the vehicle in a manner appropriate
to the prevailing weather conditions.
Preparation for winter

GS450h_OM_OM30E26U_(U)
4256-3. Do-it-yourself maintenance
6
Maintenance and care
CAUTION
The engine compartment contains many mechanisms and fluids that may move sud-
denly, become hot, or become electrically energized. To avoid death or serious
injury, observe the following precautions.
■When working on the engine compartment
●Make sure that the “POWER ON” on the multi-information display and the
“READY” indicator are both off.
●Keep hands, clothing and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, power control unit, radiator, exhaust manifold,
etc. right after driving as they may be hot. Oil and ot her fluids may also be hot.
●Do not leave anything that may burn easily, such as paper and rags, in the engine
compartment.
●Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes are flam-
mable.
■When working near the electric cooling fans or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the electric cooling fans may automatically
start to run if the air conditioning is on and/or the coolant temperature is high.
(  P. 4 3 6 )
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from get-
ting in your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter removed may cause excessive engine wear due to
dirt in the air.

GS450h_OM_OM30E26U_(U)
4356-3. Do-it-yourself maintenance
6
Maintenance and care
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixture of 50% coolant and 50% deionized
water. (Minimum temperature: -31 F [-35C])
Canada:
“Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% deionized
water. (Minimum temperature: -44 F [-42C])
For more details about coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/power control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in
the cooling system.
CAUTION
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or the cool-
ant inlet cap. ( P. 5 7 0 )
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water
and antifreeze must be used to provide proper lubrication, corrosion protection
and cooling. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.

502
GS450h_OM_OM30E26U_(U)
7-2. Steps to take in an emergency
If you think something is wrong
●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 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 feeling, pedal almost touches the
floor
If you notice any of the following symptoms, your vehicle probably
needs adjustment or repair. Contact your Lexus dealer as soon as pos-
sible.
Visible symptoms
Audible symptoms
Operational symptoms

566
GS450h_OM_OM30E26U_(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
1
2
3
1
2

5707-2. Steps to take in an emergency
GS450h_OM_OM30E26U_(U)
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 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 oper ate even if the gasoline engine stops.
Do not touch or approach rotating parts such as the fan, which may lead to fin-
gers 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 syst em has cooled down sufficiently. Adding
cool coolant to a hot hybrid system too quickly can cause da mage 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.).
●Do not use any coolant additives.
●Do not loosen the cool ant inlet cap or the
coolant reservoir cap while the hybrid sys-
tem and radiator are hot.
High temperature steam or coolant could
spray out.