coolant temperature Lexus GS450h 2018 Owner's Manual / LEXUS 2018 GS450H OWNER'S MANUAL (OM30G62U)

GS450h_OM_OM30G62U_(U)
892. Instrument cluster
2
Instrument cluster
Engine coolant temperature gauge
Displays the engine coolant temperature
Tachometer/Hybrid System Indicator
Tachometer:
Displays the engine speed in revolutions per minute.
Hybrid System Indicator:
Displays hybrid system outp ut or regeneration level (→P. 92)
Outside temperature
Displays the outside temperature within the range of -40 °F (-40 °C) to 122 °F
(50 °C). Low outside temperature indicator comes on when the ambient temperature
is 37 °F (3 °C) or lower.
Clock
Time displayed is linked to the anal og clock on the instrument panel. (→P. 315)
Speedometer
Displays the vehicle speed
Fuel gauge
Displays the quantity of fuel remaining in the tank
Multi-information display
Presents the driver with a variety of driving-related data ( →P. 95)
Displays warning me ssages in case of a malfunction ( →P. 410)
Odometer, trip meter and maintenance required information display
Odometer:
Displays the total distance the vehicle has been driven
Trip meter:
Displays the distance the vehi cle 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.
Maintenance required information: • Displays the maintenance required inform ation when the power switch is in ON
mode.
• It can be reset from of th e multi-information display. (→P. 95)
Shift position and shift range
Displays the selected shift posi tion or selected shift range (→P. 189)
1
2
3
4
5
6
7
8
9

94
GS450h_OM_OM30G62U_(U)
2. Instrument cluster
WARNING
■The information display at low temperatures
Allow the interior of the vehicle to warm up before using the liquid crystal information
display. At extremely low temperatures, th e information display monitor may respond
slowly, and display changes may be delayed.
For example, there is a lag between the dr iver’s shifting and the new gear number
appearing on the display. This lag could ca use the driver to downshift again, causing
rapid and excessive engine braking and possibly an accident resulting in death or
injury.
NOTICE
■To prevent damage to the hybr id system and its components
●While the tachometer is displayed, do not let the indicator needle of the tachometer
enter the red zone, which indicates 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. 461)

276
GS450h_OM_OM30G62U_(U)
4-6. Driving tips
Winter driving tips
●Use fluids that are appropriate to the prevailing outside temperatures.
•Engine oil
• Engine/power cont rol unit coolant
• Washer fluid
●Have a service technician inspect the condition of the 12-volt battery.
●Have the vehicle fitted with four snow 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.
Perform the following according to the driving conditions:
●Do not try to forcibly open a window or move a wiper that is frozen. Pour
warm water over the frozen area to me lt the ice. Wipe away the water imme-
diately to prevent it from freezing.
●To ensure proper operation of the c limate control system fan, remove any
snow that has accumulated on the air inlet vents in front of the windshield.
●Check for and remove any excess ice or snow that may have accumulated on
the exterior lights, vehicle’s roof, chassi s, around the tires or on the brakes.
●Remove any snow or mud from the bottom of your shoes before getting in the
vehicle.
Carry out the necessary preparations an d inspections before driving the vehi-
cle in winter. Always drive the vehicle in a manner appropriate to the prevail-
ing weather conditions.
Preparation for winter
Before driving the vehicle

350
GS450h_OM_OM30G62U_(U)
6-3. Do-it-yourself maintenance
WARNING
The engine compartment contains many mechanisms and fluids that may move suddenly,
become hot, or become electrically energize d. 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 co ntrol unit, radiator, exhaust manifold, etc.
right after driving as they may be hot. Oil and other 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 flamma-
ble.
■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. 359)
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from getting in
your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner f ilter removed may cause excessive engine wear due to dirt
in the air.

358
GS450h_OM_OM30G62U_(U)
6-3. Do-it-yourself maintenance
The coolant level is satisfactory if it is between the “FULL” and “LOW” lines on
the reservoir when the hybrid system is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. ( →P. 461)
■Power control unit coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. ( →P. 461)
■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 mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -31 °F [-35 °C])
Canada:
“Toyota Super Long Life Cool ant” 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 de aler test the cap and check for leaks in the
cooling system.
Coolant
1
2
3
1
2
3

403
GS450h_OM_OM30G62U_(U)
7
When trouble arises
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 nor-
mal.
●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 possible.
Visible symptoms
Audible symptoms
Operational symptoms

4197-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
7
When trouble arises
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 your Lexus dealer. Continuing to drive the
vehicle may be dangerous.
Indicates that the engine coolant temperature is too high
A buzzer also sounds.
→ P. 461
Indicates a malfunction in the vehicle’s charging system.
→Immediately stop the vehicle in a safe place and
contact your Lexus dealer. Continuing to drive the
vehicle may be dangerous.
Warning messageDetails/Actions
(U.S.A.) (Canada)

461
GS450h_OM_OM30G62U_(U)
7
When trouble arises
7-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge ( →P. 88) enters the red
zone or a loss of hybrid system power is experienced. (For example, the vehi-
cle 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. 410) 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 your Lexus
dealer.
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2

4627-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
The coolant level is satisfactory if it is between the “FULL” and “LOW” lines
on the reservoir.
Reservoir
“FULL”
“LOW”
Coolant inlet cap
Add coolant if necessary.
(→ P. 464)
Water can be used in an emergency
if engine coolant is unavailable.
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, tu rn 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 your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
4
1
2
3
4
5
6
7

4657-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
7
When trouble arises
WARNING
■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 h ood, 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.
NOTICE
■When adding engine/power control unit coolant
Add coolant slowly after the hybrid system has cooled down sufficiently. Adding 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 foreig n matter (such as sand or dust etc.).
●Do not use any coolant additive.
●Do not loosen the coolant inlet cap or the
coolant reservoir cap while the hybrid system
and radiator are hot.
High temperature steam or coolant could
spray out.