2015 LEXUS RX450h radiator

6504-3. Do-it-yourself maintenance
CAUTIONThe engine compartment contains many mechanisms and fluids that may move sud-
denly, become hot, or become electrically energized. To avoid death or serious injury,
observe the following precautions: ■
When working on the engine compartment ●
Make sure that the indicator on the “POWER” switch and the “READY” indicator
are both off.●
Keep hands, clothing and tools away from the moving fans and engine drive belt.●
Be careful not to touch the engine, power control 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 easi ly, such as paper and rags, in the engine
compartment.●
Do not smoke, cause sparks or expose an open flame to fuel. Fuel fumes are flam-
mable■
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 automati-
cally start to run if the air conditioning is on and/or the coolant temperature is high.
(  P. 6 6 1 )■
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.

6544-3. Do-it-yourself maintenance
Engine compartment
Brake fluid reservoir
(  P. 6 6 2 )
Engine oil filler cap
(  P. 6 5 7 )
Engine oil level dipstick
(  P. 6 5 6 )
Power control unit coolant
reservoir (  P. 6 5 9 )
Fuse boxes (  P. 6 8 9 ) Engine coolant reservoir
(  P. 6 5 9 )
Condenser (  P. 6 6 1 )
Radiator (  P. 6 6 1 )
Electric cooling fans
Power control unit coolant
radiator (  P. 6 6 1 )
Washer fluid tank (  P. 663)

6604-3. Do-it-yourself maintenance
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. 788)
■
Coolant selection
Only use “Toyota Super Long Life Coolant” or 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 mixture of 50% coolant and
50% deionized water. (Minimum temperature: -31  F [-35  C])
Canada: “Toyota Super Long Life Coolant” 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 radiators, hoses, engine/power control unit coolant reservoir
caps, drain cock and water pump.
If you cannot find a leak, have your Lexus dealer test the cap and check for leaks in
the cooling systems.

6614-3. Do-it-yourself maintenance
4
Maintenance and care
Radiator and condenser
Check the radiator and condenser an d clear away any foreign objects.
If either of the above parts are extremely dirty or you are not sure of their
condition, have your vehicle checked by your Lexus dealer. CAUTION■
When the engine and hybrid system are hot
Do not remove the coolant reservoir cap.
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 cooling. Be sure to read the antifreeze or coolant label.■
If you spill coolant
Be sure to wash it off with water to prevent damaging to parts or paint.
CAUTION■
When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause serious inju-
ries, such as burns.

7885-2. Steps to take in an emergency
If your vehicle overheats
Correction procedures
■ If “ENGINE OVERHEAT” 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 (radiator) for any
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.
● “ENGINE OVERHEAT” is shown on the multi-information display:
The engine may be overheating.
● “HYBRID SYSTEM OVERHEAT” is sh own on the multi-information
display:
A hybrid system component such as the power control unit or an
electric motor (traction motor) may be overheating.
● Steam comes out from under the hood. STEP 1
STEP 2
STEP 3

5
When trouble arises
7895-2. Steps to take in an emergency
The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator cap
Add coolant if necessary. (
 P. 6 5 5 )
Water can be used in an emer-
gency 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 air conditioning system is turned on immedi-
ately after a cold start. Confirm that the fans are operating by checking
the fan sound and air flow. If it is diff icult to check these, turn the air con-
ditioning system on and off repeatedly.
(The fans may not operate in freezing temperatures.)STEP 4
STEP 5
STEP 6

7905-2. Steps to take in an emergency
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.
■ If “HYBRID SYSTEM OVERHEAT” is shown on the multi-informa-
tion display
Stop the vehicle in a safe place. Ensure that the opening for the oil
cooler is not blocked by dirt or any
other foreign substance. If the
opening is not blocked or if the
message does not disappear after
some time the opening has been
cleaned, proceed to STEP 2.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has cooled
down, inspect the hoses and radia-
tor 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” line
“LOW” lineSTEP 7
STEP 1
STEP 2
STEP 3
STEP 4

5
When trouble arises
7915-2. Steps to take in an emergency
Add coolant if necessary. Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and check for the multi-information dis-
play.
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.STEP 5
CAUTION■
To prevent an accident or injury when in specting under the hood of your vehicle●
If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartm ent may be very hot, causing serious
injuries such as burns.●
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 fans may suddenly operate even if the gasoline engine stops.
Do not touch or approach rotating parts such as the fans, which may lead to fin-
gers or clothing (especially a tie, a scarf or a muffler) getting caught, resulting in
serious injury.●
Do not loosen the radiator cap while the hybrid system and radiator are hot.
Serious injuries, such as burns, may re sult from hot coolant and steam released
under pressure. STEP 6