2016 LEXUS RX450H radiator cap

4756-3. Do-it-yourself maintenance
6
Maintenance and care
RX450h_U_OM0E013U ■
12-volt battery
 P. 4 8 3Engine compartment
Wa s h e r f l u i d t a n k (  P. 4 8 2 )
Brake fluid reservoir (  P. 4 8 1 )
Engine oil level dipstick
(  P. 4 76 )
Engine coolant reservoir
(  P. 4 7 9 )
Power control unit coolant reservoir
(  P. 4 7 9 ) Fuse boxes (  P. 5 0 8 )
Radiator (  P. 4 8 0 )
Power control unit coolant
radiator (  P. 4 8 0 )
Condenser (  P. 4 8 0 )
Electric cooling fans
Engine oil filler cap (  P. 4 7 7 )1
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3
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5 6
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4796-3. Do-it-yourself maintenance
6
Maintenance and care
RX450h_U_OM0E013U The coolant level is satisfactory if it is between the “FULL” and “LOW” lines on
the reservoir when the hybrid system is 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. 5 74 )
■
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. 5 74 )■
Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high qu ality 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 mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -31  F [-35  C])
Canada:
“Toyota Super Long Life Coolant” is a mixt ure 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 radiator, hoses, engine/p ower 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 system.Coolant 1
2
3
1
2
3

480 6-3. Do-it-yourself maintenance
RX450h_U_OM0E013U Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by your Lexus dealer. WA R N I N G ■
When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps and radiator 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 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.
Radiator and condenser WA R N I N G ■
When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause serious injuries,
such as burns.

574 7-2. Steps to take in an emergency
RX450h_U_OM0E013U ■
“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 tu rn 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 your Lexus
dealer.
The coolant level is satisfactory if
it is between the “FULL” and
“LOW” lines on the reservoir.
Reservoir
“FULL” line
“LOW” line
Radiator capIf your vehicle overheats The following may indicate that your vehicle is overheating. ●
The needle of the engine coolant temperature gauge (  P. 97) enters the
red zone, or a loss of hybrid system po wer 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” is shown on the
multi-information display. ●
Steam comes out from under the hood.
Correction procedures 1
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5777-2. Steps to take in an emergency
7
When trouble arises
RX450h_U_OM0E013U Start the hybrid system and check if “Hybrid System Overheated Reduced
Output Power” is shown on the multi-information display.
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. WA R N I N G ■
To prevent an accident or injury when in specting 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 is operating, the gasoline engine may au tomatically start, or
the cooling fans may suddenly operate even if the gasoline engine stops. Do not
touch or approach rotating parts such as th e fans, which may lead to fingers or cloth-
ing (especially a tie, a scarf or a muffler) getting caught, resulting in serious injury.●
Do not loosen the radiator cap and the cool ant reservoir caps wh ile the hybrid system
and radiator are hot.
High temperature steam or coolant could spray out.
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. 6

651Alphabetical index
RX450h_U_OM0E013U Paddle shift switches ................. 240, 241
Panic mode ...............................................133
Panoramic moon roof .......................... 197
Jam protection function ................... 198
Operation ................................................197
Parking brake......................................... 245
Parking brake engaged
warning buzzer/message.......... 247
Warning light .......................................537
Parking lights
Light switch ............................................ 251
Replacing light bulbs ......................... 513
PCS (Pre-Collision System) ............ 279
Warning light ...................................... 538
Personal lights..........................................419
Power back door .................................... 142
Touchless power back door ......... 144
Wireless remote control ..................142
Power back door opener and
closer........................................................ 142 Power control unit coolant
Capacity ................................................. 587
Checking ............................................... 479
Preparing and checking
before winter ....................................390
Radiator ................................................. 480
Power easy access system ................. 174
Power outlets ............................... 440, 441
Power steering (Electric Power
Steering system)..................................381
Warning light ....................................... 537
Power switch...........................................232
Power windows
Door lock linked window
operation ............................................... 191
Jam protection function................... 190
Operation............................................... 189
Window lock switch ......................... 189
Pre-Collision System (PCS)............. 279
Warning light .......................................538P
* : Refer to the “NAVIGATION SYSTEM OWNER’S MANUAL”.

652 Alphabetical index
RX450h_U_OM0E013U Radar cruise control (dynamic
radar cruise control) ........................ 323
Radar cruise control
(dynamic radar cruise control
with full-speed range) ........................ 311
Radiator ....................................................480
Rear Cross Traffic Alert .................... 363
Rear door sunshades .......................... 443
Rear seat
Folding down the rear
seatbacks ............................................. 165
Rear seat heaters....................................416
Rear side marker lights
Light switch ............................................ 251
Replacing light bulbs ......................... 513
Rear turn signal lights
Replacing light bulbs ......................... 513
Turn signal lever ................................. 244
Wattage ................................................. 590
Rear view mirror
Inside rear view mirror ..................... 183
Outside rear view mirrors .............. 185
Rear window defogger ...................... 409
Rear window wiper.............................. 265 Refueling................................................... 267
Capacity .................................................584
Fuel types...............................................584
Opening the fuel tank cap ............ 267
When the fuel filler door
cannot be opened ......................... 269
Regenerative braking.............................78
Remote Touch
* .................................... 398
Replacing
Electronic key battery .................... 506
Fuses ....................................................... 508
Light bulbs...............................................513
Tires .......................................................... 549
Windshield wiper inserts ...............504
Reporting safety defects
for U.S. owners ...................................622
Resetting the message indicating
maintenance is required .................466
Rev indicator ..............................................99
Rev peak ......................................................99
Road accident cautions ........................ 83R