2016 LEXUS RX450H cooling

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

5878-1. Specifications
8
Vehicle specifications
RX450h_U_OM0E013U * : The coolant capacity is a reference quantity.
If replacement is necessary, contact your Lexus dealer.Cooling system Capacity
* 
Gasoline engine
10.7 qt. (10.1 L, 8.9 Imp. qt.) 
Power control unit
2.0 qt. (1.9 L, 1.7 Imp. qt.)
Coolant type Use either of the following:
• “Toyota Super Long Life Coolant”
• Similar high-quality ethylene glycol-based
non-silicate, non-amine, non-nitrite, and non-
borate coolant with long-life hybrid organic
acid technology
Do not use plain water alone.
Ignition system (spark plug) Make DENSO FK20HBR8
Gap 0.03 in. (0.8 mm)
NOTICE ■
Iridium-tipped spark plugs
Use only iridium-tipped spark plugs. Do not adjust the spark plug gap.
Electrical system 12-volt battery
Open voltage at 68  F (20  C): 12.6 V or higher: Fully charged
12.2 — 12.4 V: Half charged
12.0 V or lower: Discharged
(Voltage is checked 20 minutes after the hybrid
system and all lights are turned off.)
Charging rates 5 A max.

643Alphabetical index
RX450h_U_OM0E013U Coolant
Capacity ................................................ 587
Checking................................................ 479
Preparing and checking
before winter ................................... 390
Cooling system ..................................... 479
Hybrid system overheating ..........574
Cornering lights .................................... 252
Cruise control
Cruise control..................................... 335
Dynamic radar cruise control...... 323
Dynamic radar cruise control
with full-speed range ....................... 311
Cup holders ............................................ 423
Curtain shield airbags ........................... 39
Customizable features ....................... 607
Customized mode ................................377 Daytime running light system.......... 253
Defogger
Outside rear view mirrors ............409
Rear window ........................................409
Windshield............................................409
Differential .............................................. 588
Dimension ............................................... 582
Dinghy towing ......................................... 231
Display
Dynamic radar cruise control ..... 323
Dynamic radar cruise control
with full-speed range .......................311
Energy monitor..................................... 124
LDA (Lane Departure Alert
with steering control) ...................306
LKA (Lane-Keeping Assist)......... 297
Multi-information display.................102
Warning messages .......................... 543
Do-it-yourself maintenance............... 471
Doors
Automatic door locking and
unlocking system..............................139
Door lock................................................ 138
Outside rear view mirrors ............. 185
Power back door ................................ 142
Rear door child-p rotectors ............139
Side doors ...............................................136
Side windows ....................................... 189
Drive information ...................................106
Drive-start control .................... 205, 242
Driver’s seat belt reminder light .... 538
Driver’s seat position memory.......... 174 D