Page 703 of 792

7038-2. Steps to take in an emergency
8
When trouble arises
RX450h_RX450hL _U_OM48F85UAdd coolant if necessary. Water can be used in an emergency
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 immediately after a
cold start. Confirm that the fans are operating by checking the fan sound and air
flow. If it is difficult to check these, tu rn the air conditioning system on and off
repeatedly. (The fans may not operate in freezing temperatures.)
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.
Check if “Engine Coolant Temp High Stop in a Safe Place See Owner’s
Manual” 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. 5
6
7
8
Page 705 of 792

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
Page 776 of 792

776 Alphabetical index
RX450h_RX450hL _U_OM48F85UEmergency, in case of
If a warning buzzer sounds.......... 660
If a warning light turns on.............. 660
If a warning message is
displayed.............................................667
If the 12-volt battery is
discharged ........................................ 695
If the electronic key does not
operate properly.............................692
If the hybrid system will
not start ............................................... 690
If you have a flat tire ..........................673
If you lose your keys ................ 133, 135
If you think something is
wrong .................................................. 659
If your vehicle becomes
stuck ..................................................... 706
If your vehicle has to
be stopped in an
emergency........................................ 653
If your vehicle needs to be
towed................................................... 654
If your vehicle overheats ................702
Energy monitor ....................................... 124 Engine
ACCESSORY mode ..................... 240
Compartment ..................................... 597
Engine switch ...................................... 239
Hood........................................................595
How to start the hybrid
system .................................................. 239
Identification number......................... 712
If your vehicle has to be
stopped in an emergency..........653
Ignition switch (power switch) .... 239
Overheating......................................... 702
Power switch ....................................... 239
Engine coolant
Capacity................................................... 715
Checking ................................................ 601
Preparing and checking
before winter ....................................390
Engine coolant temperature
gauge .........................................................96
Engine oil
Capacity................................................... 713
Checking .............................................. 598
Preparing and checking
before winter ....................................390
Engine oil maintenance data ........... 600
Engine switch ......................................... 239
Enhanced VSC ..................................... 382
EPS
(Electronic Power Steering) ........ 383
Warning light .........................................661
EV drive mode .......................................244
EV indicator ............................................... 76
Event data recorder (EDR).....................11