Page 552 of 628
552
LX570_OM_OM60Q78U_(U) 7-2. Steps to take in an emergency
If your vehicle overheats Stop the vehicle in a safe place and tu rn off the air conditioning system, and
then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down suff iciently, inspect th e 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. ●
The needle of the engine coolant temperature gauge ( → P. 88) enters the
red zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.) ●
Steam is coming from under the hood.
Correction procedures 1
2
3
1
2
Page 553 of 628

5537-2. Steps to take in an emergency
LX570_OM_OM60Q78U_(U) 7
When trouble arises The coolant level is satisfactory if it is between the “F” and “L” lines on the res-
ervoir.
Reservoir
“F” line
“L” line
Radiator cap
Add coolant if necessary. Water can be used in an emergency if
coolant is unavailable.
Start the engine and turn the air conditioning system on to check that the air
conditioning condenser cooling fans op erate 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, turn the air conditioning system on and off repeatedly.
(The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately an d contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer. 4
1
2
3
4
5
6
7
Page 554 of 628

554 7-2. Steps to take in an emergency
LX570_OM_OM60Q78U_(U) WARNING ■
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. ●
Keep hands and clothing (especially a tie, a scarf or a muffler) away from the fans and
belts. Failure to do so may cause the hands or clothing to be caught, resulting in seri-
ous injury. ●
Do not loosen the radiator cap or the cool ant reservoir cap while the engine and radi-
ator are hot. High temperature steam or coolant could spray out.
NOTICE ■
When adding engine coolant
Add coolant slowly after the engine has cool ed down sufficiently. Adding cool coolant
to a hot engine too quickly can cause damage to the engine. ■
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.
Page 617 of 628

617Alphabetical index
LX570_OM_OM60Q78U_(U) Engine
Accessory mode............................... 206
Air cleaner ...............................................471
Compartment...................................... 473
Engine switch ...................................... 205
Exhaust gas precautions ................... 74
Hood ........................................................ 472
How to start the engine ................. 205
Identification number ...................... 559
If the engine will not start................544
If your vehicle has to be
stopped in an emergency ............. 511
Ignition switch (engine
switch) ................................................. 205
Overheating ........................................ 552
Engine compartment cover ............. 474
Engine coolant....................................... 478
Capacity .................................................562
Checking................................................478
Preparing and checking
before winter ................................... 382
Engine coolant temperature
gauge ........................................................ 88
Engine immobilizer system ................. 75
Engine oil ................................................. 475
Capacity ................................................ 560
Checking................................................475
Preparing and checking
before winter ................................... 382 Engine switch (ignition switch) ....... 205
Engine switch light
(ignition switch light)......................... 417
Event data recorder (EDR)................... 10
Exhaust gas precautions ....................... 74
First-aid kit holder ................................ 428
Flat tire ...................................................... 532
Floor mats....................................................26
Fluid
Automatic transmission ..................563
Brake........................................................ 564
Steering .................................................. 564
Washer ...................................................485
Fog lights...................................................229
Replacing light bulbs ...................... 508
Switch ...................................................... 229
Footwell lights .......................................... 417
Four-wheel AHC (Active Height
Control Suspension) ....................... 295
Easy access mode ............................ 297
Disabling the height control ......... 298
Selecting vehicle height.................. 295
Four-wheel drive system
Center differential
lock/unlock .......................................304
Four-wheel drive control
switch ...................................................303
Warning light ....................................... 522
Front automatic air conditioning
system .................................................... 399
Front doors ................................................ 115 F
* : Refer to
the “NAVIGATION SYSTEM OWNER’S MANUAL”.