2018 LEXUS RX450h radiator cap

5977-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85U■
12-volt battery
→ P. 605Engine compartment
Washer fluid tank ( → P. 604)
Brake fluid reservoir ( → P. 603)
Engine oil level dipstick
( → P. 598)
Engine coolant reservoir
( → P. 601)
Power control unit coolant reservoir
( → P. 601) Fuse boxes ( → P. 632)
Radiator ( → P. 602)
Power control unit coolant
radiator ( → P. 602)
Condenser ( → P. 602)
Electric cooling fans
Engine oil filler cap ( → P. 599)1
2
3
4
5 6
7
8
9
10
11

6017-3. Do-it-yourself maintenance
7
Maintenance and care
RX450h_RX450hL _U_OM48F85UThe 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. 702)
■
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. 702)■
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 Cool ant” 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 radiator, hoses, engine/power control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have your Lexus de aler test the cap and check for leaks in the
cooling system.Coolant 1
2
3
1
2
3

602 7-3. Do-it-yourself maintenance
RX450h_RX450hL _U_OM48F85UCheck the radiator and condenser an d 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. WARNING ■
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 WARNING ■
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.

702 8-2. Steps to take in an emergency
RX450h_RX450hL _U_OM48F85U■
“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. 96) enters the
red zone, or a loss of hybrid system power 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
2
3
1
2
4
1
2
3
4

7058-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UStart 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. WARNING ■
To prevent an accident or injury 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 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 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 coolant 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 foreig n matter (such as sand or dust etc.).●
Do not use any coolant additive. 6

783Alphabetical index
RX450h_RX450hL _U_OM48F85UPaddle shift switches ................ 247, 248
Panic mode ...............................................133
Panoramic moon roof ........................ 204
Jam protection function ................. 205
Operation ..............................................204
Parking brake......................................... 253
Parking brake engaged
warning buzzer/message......... 255
Warning light ........................................ 661
Parking lights
Light switch .......................................... 258
Replacing light bulbs ........................637
PCS (Pre-Collision System) ............ 286
Warning light .......................................662
Personal lights........................................530
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................................................... 715
Checking ................................................ 601
Preparing and checking
before winter ....................................390
Radiator .................................................. 602
Power easy access system .................. 181
Power outlets ......................................... 555
Power steering (Electric Power
Steering system)................................ 383
Warning light .........................................661
Power switch.......................................... 239
Power windows
Door lock linked window
operation ............................................. 198
Jam protection function.................... 197
Operation................................................196
Window lock switch ..........................196
Pre-Collision System (PCS)............ 286
Warning light ....................................... 662P
* : Refer to the “NAVIGATION SYSTEM OWNER’S MANUAL”.

784 Alphabetical index
RX450h_RX450hL _U_OM48F85URadar cruise control
(dynamic radar cruise control
with full-speed range) ..................... 306
Radiator .................................................... 602
Radio.......................................................... 426
Rear automatic air conditioning
system .................................................... 522
Rear Cross Traffic Alert ......................319
Rear Cross Traffic Auto
Brake ...................................................... 356
Rear door sunshades .......................... 557
Rear passengers’ seat belt
reminder light ..................................... 662
Rear seat
Folding down the rear
seatbacks ............................................. 168
Rear side marker lights
Light switch .......................................... 258
Replacing light bulbs ........................637
Rear turn signal lights
Replacing light bulbs ........................637
Turn signal lever ................................. 252
Wattage ....................................................719 Rear view mirror
Inside rear view mirror....................... 191
Outside rear view mirrors ..............193
Rear window defogger ........................ 516
Rear window wiper .............................. 272
Refueling................................................... 274
Capacity................................................... 712
Fuel types................................................. 712
Opening the fuel tank cap .............274
When the fuel filler door
cannot be opened ..........................277
Regenerative braking............................. 76
Remote Touch
* .................................... 500
Replacing
Electronic key battery .....................630
Fuses ........................................................ 632
Light bulbs............................................. 637
Tires .......................................................... 673
Windshield wiper inserts ............... 628
Reporting safety defects
for U.S. owners ...................................752
Resetting the message indicating
maintenance is required ................ 588
Rev indicator ............................................. 98
Rev peak ..................................................... 98
Road accident cautions .......................... 81R