2017 LEXUS RC300H coolant reservoir

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)
1
2
3
4
5
6
7
8
9
10

4787-3. Do-it-yourself maintenance
RC300h_EE(OM24740E)
■Engine coolant reservoir
The coolant level is satisfactory if it is between the “FULL” and “LOW” lines on
the reservoir when the hybrid system is cold.
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line, add coolant up to the “FULL”
line. ( P. 587)
■Power control unit coolant reservoir
The coolant level is satisfactory if it is between the “F” and “L” lines on the reser-
voir when the hybrid system is cold.
Reservoir cap
“F” line
“L” line
If the level is on or below the “L” line, add coolant up to the “F” line. ( P. 587)
Coolant
1
2
3
1
2
3

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.

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.
4
1
2
3
5
6
7

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.
1
2
3
1
2
4
1
2
3
5

5908-2. Steps to take in an emergency
RC300h_EE(OM24740E)
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 dealer or
repairer, or another duly qualified and equipped professional.
If the message is not displayed:
Have the vehicle inspected at the nearest authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
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 “READY” indicator is off.
When the hybrid system operating, the ga soline engine may automatically start, or the cooling fan may suddenly operate even if the gasoline engine stops. Do not touchor approach rotating parts such as the belt and fan, which may lead to fingers or
clothing (especially a tie, a scarf or a mu ffler) getting caught, resulting in serious injury.
6
●Do not loosen the coolant reservoir caps orradiator cap while the hybrid system and radi-
ator are hot. High temperature steam or coolant couldspray out.