2017 LEXUS RC300H cooling

4707-3. Do-it-yourself maintenance
RC300h_EE(OM24740E)
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 “ACCESSORY” or “IGNITION ON” on the multi-informationdisplay 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, radiator, exhaust manifold, etc. right after drivingas 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 enginecompartment.
●Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes are flamma-
ble.
●Be extremely cautious when working on the 12-volt battery. It contains poisonous and corrosive sulfuric acid.
●Take care because brake fluid can harm your hands or eyes and damage painted sur- faces. If fluid gets on your hands or in your eyes, flush the affected area with cleanwater immediately.
If you still experience discomfort, consult a doctor.
■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. 480)
■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 filter removed may cause excessive engine wear due to dirt
in the air.
■If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear or when
the fluid level in the accumulator is high. If the reservoir needs frequent refillin g, it may indicate a serious problem.

4737-3. Do-it-yourself maintenance
7
Maintenance and care
RC300h_EE(OM24740E)
■12-volt battery
 P. 481
Engine compartment
Power control unit coolant
reservoir ( P. 478)
Engine oil level dipstick
( P. 474)
Engine coolant reservoir
( P. 478)
Engine oil filler cap
( P. 475)
Fuse box ( P. 514)
Washer fluid tank ( P. 480)
Electric cooling fans
Condenser ( P. 480)
Power control unit coolant
radiator ( P. 480)
Engine coolant radiator
( P. 480)
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4797-3. Do-it-yourself maintenance
7
Maintenance and care
RC300h_EE(OM24740E)
■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 hybridorganic 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 any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
■If the coolant level drops within a short time of replenishing
Visually check the radiators, hoses, engine /power control unit coolant reservoir caps,
drain cock and water pump. If you cannot find a leak, have any authorized Lexus dealer or repairer, or another dulyqualified and equipped professional, test the cap and check for leaks in the cooling sys-
tem.
WARNING
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or water filler cap. ( P. 590)
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.

5538-2. Steps to take in an emergency
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When trouble arises
RC300h_EE(OM24740E)
Indicates a malfunction in the tire pressure warning sys- tem
 Stop the vehicle in a safe place and turn the power switch off then on again.If the tire pressure warning indicator flashes for 1
minute then illuminates, th ere is a malfunction in the system. Have the vehicle inspected by any autho-rized Lexus dealer or repairer, or another duly qual-
ified and equipped professional.
Indicates that the tire position information cannot be rec- ognized Drive for a short while and check if the display
updates. If the radio wave conditions improve, the displaymay return to normal. If the tire pressure is still not
displayed after driving for several minutes, stop the vehicle in a safe place, turn the power switch offthen on again, and start driving.
If the tire pressure is still not displayed even after repeating this process several times, have the vehi-cle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
Maintenance of the hybrid battery (traction battery)
cooling component is required The filter may be clogged, the air intake vent may beblocked or there may be a gap in the duct
 Have maintenance performed on the hybrid battery (traction battery) cooling component by any autho-rized Lexus dealer or repairer, or another duly qual-
ified and equipped professional.
Indicates that the washer fluid level is low  Add washer fluid.
Indicates that remaining fuel is approximately 10 L (2.6 gal., 2.2 Imp. gal.) or less Refuel the vehicle.
Warning messageDetails/Actions

5868-2. Steps to take in an emergency
RC300h_EE(OM24740E)
NOTICE
■When handling jumper cables
When connecting the jumper cables, ensure that they do not become entangled in the cooling fans or belt.
■Exclusive jump starting terminal
The exclusive jump starting terminal is intended to charge the 12-volt battery on your vehicle from another vehicle in an emergency. Do not use the exclusive jump starting
terminal to jump start another vehicle.

5878-2. Steps to take in an emergency
8
When trouble arises
RC300h_EE(OM24740E)
●The hybrid system coolant temperature gauge (P. 115) is in the red zone or
a loss of hybrid system power is experi enced. (For example, the vehicle speed
does not increase.)
●“Engine Coolant High Temperature” or “Hybrid System Overheat Output
Power is limited” 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 High Temperature” 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 radiator core (radi-
ator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact any autho- rized Lexus dealer or repairer, oranother duly qualified and
equipped professional.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
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5888-2. Steps to take in an emergency
RC300h_EE(OM24740E)
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 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 ai r 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 fan 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 authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
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5898-2. Steps to take in an emergency
8
When trouble arises
RC300h_EE(OM24740E)
■If “Hybrid System Overheat Output Power is limited” 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 dealer or repairer, or
another duly qualified and
equipped professional.
The coolant level is satisfactory if
it is between the “F” and “L” lines
on the reservoir.
Reservoir
“F”
“L”
Add coolant if necessary.
Water can be used in an emergency
if coolant is unavailable.
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