overheating LEXUS RCF 2018 Owners Manual

15Pictorial index
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)Doors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 145Locking/unlocking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 145
Opening/closing the side window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 182
Locking/unlocking by using the me chanical key . . . . . . . . . . . . . . . . . . . . . . . . P. 518
Warning lights/warning messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 454, 462
Windshield wipers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 233 Precautions against winter season . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 320
To prevent freezing (windshield wiper de-icer)
* . . . . . . . . . . . . . . . . . . . . . . . P. 339
Precautions against car wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 378
Fuel filler door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 241Refueling method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P . 241
Fuel type/fuel tank capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 540
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 412Tire size/inflation pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 548
Winter tires/tire chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 32 0
Checking/rotation/tire pressure warning system . . . . . . . . . . . . . . . . . . . . . . . P. 412
Coping with flat tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 489, 502
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 393Opening. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 393
Engine oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 540
Coping with overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 526
Warning messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 463
Headlights/turn signal lights/side marker lights . . . . . . . . . . . . . P. 221, 225
Parking lights/daytime running lights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .P. 225
Front fog lights
* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. 232 1
2
3
4
5
Light bulbs of the exte rior lights for driving
(Replacing method: P. 432, Watts: P. 553)
* : If equipped6
7
8

952. Instrument cluster
2
Instrument cluster
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)■
The meters and display illuminate when
The engine switch is in IGNITION ON mode. ■
Instrument panel brightness adjustment
The instrument panel brightness levels when the tail lights are on and off can be adjusted
individually. However, when the surroundings are bright (dayti me, etc.), turning on the tail
lights will not change the inst rument panel brightness. At th is time, any adjustments made
to the instrument panel brightness levels will be applied to both settings at once. ■
Outside temperature display ●
In the following situations, the correct outside temperature may not be displayed, or the
display may take longer than normal to change.
• When stopped, or driving at low speeds (less than 12 mph [20 km/h])
• When the outside temperature has changed suddenly (at the entrance/exit of a
garage, tunnel, etc.) ●
When “_ _”or “E” is displayed, the system may be malfunctioning.
Take your vehicle to your Lexus dealer. ■
Pop-up display ●
In some situations, such as when a switch operation is performed, a pop-up display will
be temporarily displayed on the multi-info rmation display or the odometer/trip meter
screen (F SPORT models). ●
Some pop-up displays can be set on/off. (  P. 111)■
Customization
The meter display can be customized on the multi-information display. (  P. 111)
NOTICE ■
To prevent damage to the engine and its components●
Do not let the indicator needle of the tachometer enter the red zone, which indicates
the maximum engine speed. ●
The engine may be overheating if the engine coolant temperature gauge is in the red
zone (H). In this case, immediately stop the vehicle in a safe place, and check the
engine after it has cooled completely. (  P. 526)

102 2. Instrument cluster
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)■
Instrument panel brightness adjustment
The instrument panel brightness levels when the tail lights are on and off can be adjusted
individually. However, when the surroundings are bright (dayti me, etc.), turning on the tail
lights will not change the inst rument panel brightness. At th is time, any adjustments made
to the instrument panel brightness levels will be applied to both settings at once. ■
Dimming the analog speedometer lighting
The analog speedometer lighting will be dimm ed when the ambient light is bright, such
as during the daytime, and SPORT S or SPORT S+ mode is selected.■
Outside temperature display ●
In the following situations, the correct outside temperature may not be displayed, or the
display may take longer than normal to change.
• When stopped, or driving at low speeds (less than 12 mph [20 km/h])
• When the outside temperature has changed suddenly (at the entrance/exit of a
garage, tunnel, etc.) ●
When “  ” or “E” is displayed, the sy stem may be malfunctioning.
Take your vehicle to your Lexus dealer. ■
Pop-up display ●
In some situations, such as when a switch operation is performed, a pop-up display will
be temporarily displayed on the multi-information display.●
Some pop-up displays can be set on/off. (  P. 129)■
Liquid crystal display
Small spots or light spots may appear on the display. This phenomenon is characteristic
of liquid crystal displays, and there is no problem continuing to use the display.■
Customization
The meter display can be customized on the multi-information display. (  P. 129)
NOTICE ■
To prevent damage to the engine and its components●
Do not let the indicator of the tachometer enter the red zone, as it represents the
engine speed range which exceeds the maximum safe engine speed. ●
In the following situations, th e engine may be overheating. In this case, immediately
stop the vehicle in a safe place, and check the engine after it has cooled completely.
(  P. 526)
• The engine coolant temperature gauge indicator ( ) is in the red zone and flash-
ing.
• The engine oil temperature gauge indicator ( ) is in the red zone and flashing.

210 4-2. Driving procedures
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)■
Auto power off function
If the vehicle is left in ACCESSORY mode for more than 20 minutes or IGNITION ON
mode (the engine is not running) for more than an hour with the shift lever in P, the engine
switch will automatically turn off. However, this function cannot entirely prevent battery
discharge. Do not leave the vehicle with the engine switch in ACCESSORY or IGNI-
TION ON mode for long periods of ti me when the engine is not running.■
Electronic key battery depletion
 P. 143 ■
Conditions affe cting operation
 P. 158 ■
Notes for the entry function
 P. 159 ■
If the engine does not start ●
Check that the shift lever is se curely set in P. The engine ma y not start if the shift lever is
displaced out of P. ●
The engine immobilizer system ma y not have been deactivated. (  P. 79)
Contact your Lexus dealer. ■
Steering lock
After turning the engine switch off and opening and closing the doors, the steering wheel
will be locked due to the steering lock func tion. Operating the engine switch again auto-
matically cancels the steering lock. ■
When the steering lock cannot be released
■
Steering lock motor overheating prevention
To prevent the steering lock motor from overheating, operation of the motor may be sus-
pended if the engine is turned on and off repeat edly in a short period of time. In this case,
refrain from operating the engine switch. After about 10 seconds, the steering lock
motor will resume functioning. ■
When “Access System with Elec. Key Malf unction See Owner’s Manual” is displayed
on the multi-information display
The system may be malfunctio ning. Have the vehicle inspected by your Lexus dealer
immediately. ■
If the electronic key battery is depleted
 P. 427“Steering Wheel Lock Press Engine Switch
while Turning Wheel” w ill be displayed on the
multi-information display.
Check that the shift leve r is in P. Press the
engine switch while turn ing the steering wheel
left and right.

3174-5. Using the driving support systems
4
Driving
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)■
Sounds and vibrations caused by the ABS, brake assist, VSC, TRAC, hill-start assist
control and VGRS systems ●
A sound may be heard from the engine compartment when the brake pedal is
depressed repeatedly, when the engine is started or just after the vehicle begins to
move. This sound does not indicate that a malfunction has occurred in any of these sys-
tems. ●
Any of the following conditions may occur when the above systems are operating.
None of these indicates that a malfunction has occurred.
• Vibrations may be felt through the vehicle body and steering.
• A motor sound may be heard afte r the vehicle comes to a stop.
• The brake pedal may pulsate slig htly after the ABS is activated.
• The brake pedal may move down s lightly after the ABS is activated.■
EPS, VGRS and DRS operation sound
When the steering wheel is operated, a motor sound (whirring sound) may be heard.
This does not indicate a malfunction. ■
Reactivation of the TRAC/VSC systems
Even after the TRAC/VSC systems have been turned off, turning the engine off and then
on again will automatically reactivate the TRAC/VSC systems. ■
Reactivation of the TRAC sy stem linked to vehicle speed
When only the TRAC system is turned off, the TRAC system will turn on when vehicle
speed increases. However, wh en both TRAC/VSC systems are turned off, the systems
will not turn on even when vehicle speed increases.■
Reduced effectiveness of the EPS system
The effectiveness of the EPS system is reduced to prevent the system from overheating
when there is frequent steering input over an extended period of time. The steering
wheel may feel heavy as a result . Should this occur, refrain from excessive steering input
or stop the vehicle and turn the engine off. The EPS system should return to normal
within 10 minutes. ■
Operating conditions of hill-start assist control
When the following four conditions are met, the hill-start assist control will operate:●
The shift lever is in a position other than P or N (when starting off forward/backward on
an upward incline). ●
The vehicle is stopped. ●
The accelerator pedal is not depressed. ●
The parking brake is not engaged. ■
Automatic system cancelation of hill-start assist control
The hill-start assist control will turn off in any of the following situations: ●
The shift lever is moved to P or N. ●
The accelerator pedal is depressed. ●
The parking brake is engaged. ●
Approximately 2 seconds elapse af ter the brake pedal is released.

344 5-1. Using the air conditioning system
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)Turn the heated steering wheel on/off The indicator light comes on when the
heated steering wheel is operating.
●
The heated steering wheel can be used wh en the engine switch is in IGNITION ON
mode. ●
The heated steering wheel will automati cally turn off after about 30 minutes.Heated steering wheel 
/seat heaters 
/seat ventila-
tors 
 : If equippedHeated steering wheel and seat heaters heat the side grips of the steering
wheel and seats, respectively. Seat vent ilators maintain good ventilation using
a fan built into the seat. WARNING ●
Care should be taken to prevent injury if anyone in the following categories comes in
contact with the steering wheel or seats when the heater is on:
• Babies, small children, the elderly, the sick and the ph ysically challenged
• Persons with sensitive skin
• Persons who are fatigued
• Persons who have taken alcohol or drugs that induce sleep (sleeping drugs, cold
remedies, etc.) ●
Observe the following precautions to prevent the minor burns or overheating
• Do not cover the seat with a blanket or cushion when using the seat heater.
• Do not use seat heater more than necessary.
NOTICE ●
Do not put heavy objects that have an unev en surface on the seat and do not stick
sharp objects (needles, nails, etc.) into the seat. ●
To prevent battery discharge, do not us e the functions when the engine is off.
Heated steering wheel

526 7-2. Steps to take in an emergency
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)●
The engine coolant temperature gauge (  P. 91, 96) is in the red zone or a
loss of engine power is experienced. (For example, the vehicle speed does not
increase.) ●
“Engine Coolant Temp High Stop in a Safe Place See Owner's Manual” is
shown on the multi-information display. ●
Steam comes out from under the hood.
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.If your vehicle overheats The following may indicate that your vehicle is overheating.
Correction procedures 1
2

619Alphabetical index
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)Cleaning......................................... 376, 381
Aluminum wheels .............................. 377
Exterior....................................................376
Interior ...................................................... 381
Seat belts ............................................... 382
Clock ......................................................... 355
Coat hooks..............................................358
Compass .................................................. 366
Condenser .............................................. 406
Console box ............................................ 351
Cooling system ..................................... 404
Engine overheating...........................526
Cruise control
Dynamic radar cruise control..... 268
Cup holders ............................................ 352
Current fuel consumption ....... 108, 122
Curtain shield airbags ........................... 40
Customizable features ....................... 569 Daytime running light system...........226
Defogger
Outside rear view mirrors ............338
Rear window........................................338
Windshield............................................338
Differential
Front differential .................................545
Rear differential................................... 546
Dimension ............................................... 536
Dinghy towing ....................................... 206
Display
Drive information...................... 108, 122
Dynamic radar cruise control .....268
LDA (Lane Departure Alert
with steering control) ................... 265
Multi-information display....... 103, 118
Warning message.............................460
Distance ...........................................108, 122
Do-it-yourself maintenance............... 391
Door courtesy lights
Location ................................................. 347
Door lock
Doors.........................................................145
Smart access system with
push-button start ..............................156
Wireless remote control..................140 D

621Alphabetical index
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)Emergency, in case of
If a warning buzzer sounds...........453
If a warning light turns on...............453
If a warning message
is displayed ....................................... 460
If the electronic key
does not operate properly ......... 518
If the engine will not start................. 516
If the vehicle battery is
discharged ......................................... 522
If you have a flat tire .............489, 502
If you think something
is wrong................................................ 451
If your vehicle becomes stuck .....532
If your vehicle has to be
stopped in an emergency ..........443
If your vehicle needs
to be towed ....................................... 444
If your vehicle overheats ................526
Engine ....................................................... 539
ACCESSORY mode..................... 208
Compartment......................................397
Engine switch .......................................207
Hood ........................................................393
How to start the engine ..................207
Identification number ...................... 538
If the engine will not start................. 516
Ignition switch (engine switch)....207
Overheating .........................................526 Engine coolant ...................................... 404
Capacity................................................. 544
Checking ............................................... 404
Preparing and checking
before winter ........................320, 320
Engine coolant temperature
gauge ..................................................91, 96
Engine immobilizer system .................. 79
Engine oil ................................................. 400
Capacity.................................................540
Checking .............................................. 400
Preparing and checking
before winter ........................320, 320
Engine oil maintenance data ........... 403
Engine oil temperature gauge............96
Engine switch ..........................................207
Enhanced VSC ....................................... 312
EPS (Electric Power Steering) ......... 313
Warning light ....................................... 454
Event data recorder (EDR)................... 10
Expert mode ............................................ 316

627Alphabetical index
RC350_RC300 AWD_RC3 00_RC F_U(OM24748U)Odometer ........................................... 91, 96
Oil
Engine oil............................................... 540
Front differential oil........................... 545
Rear differential oil ............................ 546
Opener
Hood ........................................................393
Trunk ........................................................... 151
Outer foot lights.................................... 347
Outside rear view mirrors ..................178
Adjusting and folding........................ 178
Blind spot monitor............................ 290
Linked mirror function
when reversing ..................................179
Mirror position memory .................. 166
Outside rear view
mirror defoggers ........................... 338
Outside temperature...................... 91, 96
Overheating ........................................... 526 Paddle shift switches................... 215, 216
Parking assist sensors
(intuitive parking assist).................. 280
Parking brake .........................................222
Parking lights ..........................................225
Light switch........................................... 225
Replacing light bulbs ....................... 439
PCS (Pre-Collision System)............ 250
Warning light ....................................... 454
Personal lights ....................................... 349
Pop-up display ................................. 111, 129
Power outlet ........................................... 355
Power steering (Electric power
steering system) .................................. 313
Warning light ....................................... 454
Power windows....................................... 182
Door lock linked
window operation ...........................184
Jam protection function................... 183
Operation................................................182
Window lock switch ..........................182
Pre-Collision System (PCS)............ 250
Warning light ....................................... 454O P
* : Refer to the “NAVIGATIO N AND MULTIMEDIA SYSTEM
OWNER’S MANUAL”.