2018 Lexus GS450h coolant

GS450h_OM_OM30G62U_(U)
3596-3. Do-it-yourself maintenance
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Maintenance and care
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by your Lexus dealer.
WARNING
■When the hybrid system is hot
Do not remove the engine/power control un it coolant reservoir caps or the coolant
inlet cap. ( →P. 465)
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 cool-
ing. 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.
Radiator and condenser
WARNING
■When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause serious injuries,
such as burns.

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GS450h_OM_OM30G62U_(U)
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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)

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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
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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.
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4637-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
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When trouble arises
■If “Hybrid System Overheated Reduced Output Power” is shown on the
multi-information displayStop the vehicle in a safe place.
Stop the hybrid system an d 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 your Lexus
dealer.
The coolant level is satisfactory 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 emergency
if power control unit coolant is
unavailable.
Start the hybrid system and check for the multi-information display.
If the message does not disappear:
Stop the hybrid system and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer.
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4647-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
■When adding coolant
Add coolant in accordance with the following procedure.
Remove caps A and B.
Add coolant through the inlet of cap A up to the “[GR-HV] B” line, and
then install cap A.
Add coolant through the inlet of cap B until it is full, and then install cap B.
Cap A
Cap B
“[GR-HV] B” line (Target fill line)1
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4657-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
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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.