coolant LEXUS GS300H 2019 User Guide

4106-3. Do-it-yourself maintenance
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■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.
“Toyota Super Long Life Coolant” is a mixt ure of 50% coolant and 50% deionized water. (Minimum temperature: -35 C [-31F])
For more details about coolant, contact an y authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/p ower control unit coolant reservoir caps,
drain cock and water pump. If you cannot find a leak, have any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer, test the cap an d check for leaks in the cooling system.
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. 540) 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.

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7-2. Steps to take in an emergency
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
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 sy mptoms, your vehicle probably needs
adjustment or repair. Contact any authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer as soon as possible.
Visible symptoms
Audible symptoms
Operational symptoms

4757-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
Indicates a malfunction in:
• The SRS airbag system; or • The seat belt pretensioner systemA buzzer also sounds.
 Have the vehicle inspected by any authorized Lexus retailer or Lexus authorized repairer, or any reliablerepairer.
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 retailer or Lexus
authorized repairer, or any reliable repairer.
Indicates that the engine coolant temperature is too high
A buzzer also sounds.  P. 535
Indicates a malfunction in the vehicle’s charging system.  Immediately stop the vehicle in a safe place and contact any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.
Warning messageDetails/Actions

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7-2. Steps to take in an emergency
When trouble arises
GS450h_300h_OM_OM30F92E_(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. 466) 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 retailer or Lexus authorized repairer, or any reli-able repairer.
The following may indicate that your vehicle is overheating.
Correction procedures
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5367-2. Steps to take in an emergency
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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. 539)
Water can be used in an emergency if engine coolant is unavailable.
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5377-2. Steps to take in an emergency
7
When trouble arises
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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 op erating 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 any authorized Lexus
retailer or Lexus authorized repairer, or any reliable repairer.
If the fans are operating:
Have the vehicle inspected at the nearest any authorized Lexus retailer or
Lexus authorized repairer, or any reliable repairer.
■If “Hybrid System Overheated Reduced Output Power” is shown on the
multi-information display
Stop 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 retailer or Lexus authorized repairer, or any reli-able repairer.
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5387-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
The coolant level is satisfactory if it is between the “FULL”/“F” and “LOW”/
“L” lines on the reservoir.
Reservoir
“FULL”/“F”
“LOW”/“L”
Add coolant if necessary.
Water can be used in an emergency if po wer 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 any authorized Lexus retailer or Lexus autho-
rized repairer, or any reliable repairer.
If the message is not displayed: Have the vehicle inspected at the nearest any authorized Lexus retailer or Lexus
authorized repairer, or any reliable repairer.
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5397-2. Steps to take in an emergency
7
When trouble arises
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■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/“[AR/GR] B” line,
and then install cap A.
Add coolant through the inlet of cap B un til it is full, and then install cap B.
GS300h only: When inst alling cap B, apply coolant to the O-ring on the end of cap B.
Cap A
Cap B
GS450h: “[GR-HV] B” line (Target fill line) GS300h: “[AR/GR] B” line (Target fill line)
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GS300h GS450h
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5407-2. Steps to take in an emergency
GS450h_300h_OM_OM30F92E_(EE)
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, orthe 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) getting caught, resulting in serious injury.
●Do not loosen the coolant inlet cap or thecoolant reservoir caps while the hybrid sys-tem and radiator are hot.
High temperature steam or coolant could spray out.
GS450h
GS300h

5417-2. Steps to take in an emergency
7
When trouble arises
GS450h_300h_OM_OM30F92E_(EE)
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 foreign matter (such as sand or dust etc.).
●Do not use any coolant additive.