2015 LEXUS RX450h engine coolant

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)

6594-3. Do-it-yourself maintenance
4
Maintenance and care
Coolant
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the engine and hybrid system are cold.
Engine 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)NOTICE■
To prevent serious engine damage
Check the oil level on a regular basis.■
When replacing the engine oil ●
Be careful not to spill engine oil on the vehicle components.●
Avoid overfilling, or the engine could be damaged.●
Check the oil level on the dipstick every time you refill the vehicle.●
Be sure the engine oil filler cap is properly tightened.

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.

7325-1. Essential information
If you think something is wrong 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
● Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temper ature gauge needle continually points
higher than normal.
■ Audible symptoms
● 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
■ Operational symptoms
● Engine missing, stumbling or running rough
● 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, sp ongy feeling, pedal almost touches
the floor

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
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

7925-2. Steps to take in an emergency
NOTICE■
When adding engine/power control unit coolant
Wait until the hybrid system has cooled down before adding engine/power control
unit coolant.
When adding coolant, do so slowly. 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 additives.