4967-3. Do-it-yourself maintenance
RC350/RCF_U (OM24636U)
■Situations in which the tire pressure warning system may not operate properly
●In the following cases, the tire pressure warning system may not operate properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equipment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains etc. are equipped.
• Lock nuts are equipped.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects the radio wave signals is installed.
• If there is a lot of snow or ice on the vehicle, particularly around the wheels or wheel housings.
• If the tire inflation pressure is extremely higher than the specified level.
• If tires not equipped with tire pressure warning valves and transmitters are used.
• If the ID code on the tire pressure warning valves and transmitters is not registered in the tire pressure warning computer.
●Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large display, air-
port or other facility th at generates strong radio waves or electrical noise
• When carrying a portable radio, cellular phone, cordless phone or other wireless
communication device
If tire position information is not correctl y displayed due to the radio wave conditions,
the display may be corrected by driving and changing the radio wave conditions.
●When the vehicle is parked, the time taken for the warning to start or go off could be
extended.
●When tire inflation pressure declines rapidly for example when a tire has burst, the
warning may not function.
■The initialization operation
●Make sure to carry out initialization af ter adjusting the tire inflation pressure.
Also, make sure the tires are cold before carry ing out initialization or tire inflation pres-
sure adjustment.
●If you have accidentally turned the engine swit ch off during initialization, it is not neces-
sary to press the reset switch again as init ialization will restart automatically when the
engine switch has been turned to IG NITION ON mode for the next time.
●If you accidentally press the reset switch when initialization is not necessary, adjust the
tire inflation pressure to the specified level when the tires are co ld, and conduct initial-
ization again.
■When initialization of the tire pressure warning system has failed
Initialization can be completed in a few minutes. However, in the following cases, the set-
tings have not been recorded and the system will not operate properly. If repeated
attempts to record tire inflation pressure settings are unsuccessful, have the vehicle
inspected by your Lexus dealer.
●When operating the tire pressure warning reset switch, the tire pressure warning light
does not blink 3 times.
●After carrying out the initialization procedure, the tire pressure warning light blinks for 1
minute then stays on after driving for 20 minutes.
4987-3. Do-it-yourself maintenance
RC350/RCF_U (OM24636U)
WA R N I N G
■When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drivetrain as well as dangerous han-
dling characteristics, which may lead to an accident resulting in death or serious injury.
●Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix differently constructed tires (radial, bias-belted or bias-ply tires).
●Do not mix summer, all season and snow tires.
●Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously.
●Vehicles with a compact spare tire: Do not tow if your vehicle has a compact spare
tire installed.
●Vehicles with an emergency tire puncture repair kit: Do not tow anything if a tire that
has been repaired using the emergency tire puncture repair kit is installed. The load
on the tire may cause unexpected damage to the tire.
■When initializing the tire pressure warning system
Do not operate the tire pressure warning reset switch without first adjusting the tire
inflation pressure to the specified level. Otherwise, the tire pressure warning light may
not come on even if the tire inflation pressu re is low, or it may come on when the tire
inflation pressure is actually normal.
■Caution regarding interference with electronic devices
●Users of any electrical medical device other than implantable cardiac pacemakers,
cardiac resynchronization therapy-pacemakers or implantable cardioverter defibril-
lators should consult the ma nufacturer of the device for information about its opera-
tion under the influence of radio waves.
Radio waves could have unexpected effe cts on the operation of such medical
devices.
●People with implantable cardiac pacemakers,
cardiac resynchronization therapy-pacemak-
ers or implantable cardioverter defibrillators
should not come within 17.7 in. (450 mm) of
the tire pressure warning system initiators.
The radio waves may affect the operation of
such devices.
5368-2. Steps to take in an emergency
RC350/RCF_U (OM24636U)
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors, side
impact sensors (door), side impact sensors (f ront), side impact sensors (rear), driver’s
seat position sensor, driver’s seat belt buck le switch, front passenger occupant classifica-
tion system, “AIR BAG ON” indicator light, “A IR BAG OFF” indicator light, front passen-
ger’s seat belt buckle switch, seat belt pretensioners, ai rbags, interconnecting wiring and
power sources. ( P. 41)
■Front passenger detection sensor, seat belt reminder and warning buzzer
If luggage is placed on the front passenger seat, the front passenger detection sensor
may cause the warning light to flash and the wa rning buzzer to sound even if a passenger
is not sitting in the seat.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving trips.
If the light does not go off even after severa l trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning light (warning buzzer)
When the battery charge becomes insufficie nt of the voltage temporarily drops, the
electric power steering system warning light may come on and the warning buzzer may
sound.
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch will not tu rn off the tire pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air
leaks and tire inflation pressure changes caused by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with the spare tire (if equipped)
The spare tire is not equipped with a tire pr essure warning valve and transmitter. If a tire
goes flat, the tire pressure warning light will no t turn off even though the flat tire has been
replaced with the spare tire.
■Conditions that the tire pressure warning system may not function properly
P. 4 9 6
■If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the
engine switch is turned to IGNITION ON mo de, have it checked by your Lexus dealer.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.
5548-2. Steps to take in an emergency
RC350/RCF_U (OM24636U)
■Wa r n i n g m e s s a g e s
The warning message illustrations used are intended as examples, and may differ from
the image that is actua lly displayed on the multi-information display.
■Warning message in radar cruise mode (if equipped)
In the following situations, the warning messag e may not be displayed even if vehicle-to-
vehicle distance decreases:
●When your vehicle and the vehicle ahead are traveling at the same speed or the vehicle
ahead is traveling more quickly than your vehicle
●When the vehicle ahead is traveling at a very low speed
●Immediately after cruise control speed is set
●At the instant the accelerator pedal is depressed
■The LDA (Lane Departure Alert) lane departure warning function
In the following situations, the warning messag e will not be displayed even if a lane line is
crossed.
●When the vehicle speed deviates from the operating range of the LDA system func-
tions
●When the lane lines cannot be recognized
■Reset the maintenance data (U.S.A. only)
Make sure to reset the oil change system. ( P. 4 6 7 )
■Conditions that the tire pressure warning system may not function properly
P. 4 9 6
■Warning buzzer
P. 5 3 6
679Alphabetical index
RC350/RCF_U (OM24636U)
SwitchesActive rear wing switch ................... 310
ASC (Active Sound Control) switch................................................... 206
Audio remote control switches ............................................... 327
Automatic High Beam system ..................................................... 211
BSM (Blind spot monitor) switch.................................................... 297
Cruise control switch........... 229, 233
Door lock switches .............................137
Driving mode select switch ..........278
Driving position memory switches ................................................ 157
Dynamic radar cruise control switch ................................... 233
Emergency flashers switch ........... 522
Engine switch ........................................ 193
Fog light switch .................................... 216
Garage door opener switches .............................................. 440
Heated steering wheel switch....................................................425
Ignition switch ....................................... 193
Intuitive parking assist switch ...... 255
LDA (Lane Departure Alert) switch....................................................249
Light switches ..................................... 208
Meter control switches ............. 105, 111 Moon roof switches ........................... 175
Outside rear view mirror
switches ............................................... 168
Paddle shift switches..............201, 202
PCS OFF switch .................................. 291
Power door lock switch ................... 137
Power window switches .................... 171
Rear window and outside rear view mirror defoggers
switch ................................................... 420
Seat heater switches ........................ 426
Seat ventilator switches ...................427
Snow mode switch ...........................200
“SOS” button .........................................451
Talk switch............................................ 388
Telephone switches......................... 388
Tilt and telescopic steering control switch ..................164
Tire pressure warning reset switch ................................................... 493
Trunk opener main switch .............. 142
Trunk opener switch ............................141
TVD (Torque Vectoring Differential) switch ........................... 313
Vehicle-to-vehicle distance button ....................................................237
VSC OFF switch ............................... 284
Window lock switch ............................ 171
Windshield wiper and washer switch ........................... 217
Windshield wiper de-icer switch ..................................................... 421
680Alphabetical index
RC350/RCF_U (OM24636U)
Tachometer .......................................90, 96Variable red zone................................. 101
Tail lights...................................................208 Light switch .......................................... 208
Replacing light bulbs ......................... 519
Talk switch
*............................................388
Telephone switches
*..........................388
Theft deterrent system Alarm........................................................... 78
Engine immobilizer system.............. 76
Luggage security system .................142
Theft prevention labels ...................... 80
Tire inflation pressure .........................500 Maintenance data ............................... 614
Tire inflation pressure display function ................................................492
Warning light ...................................... 535
Tire information ..................................... 623 Glossary ................................................ 630
Size ............................................................626
Tire identification number..............625
Uniform Tire Quality Grading.............................................. 628 Tire pressure warning system ..........492
Initializing ............................................... 492
Installing tire pressure warning valves and transmitters................ 492
Registering ID codes ....................... 493
Tire pressure warning reset switch ................................................... 493
Warning light .......................................535
Tires ............................................................. 491 Chains .......................................................316
Checking .................................................491
Emergency tire puncture repair kit .............................................. 574
If you have a flat tire ............. 560, 574
Inflation pressure..................................614
Information............................................ 623
Replacing .............................................. 560
Rotating tires ..........................................491
Size .............................................................614
Snow tires ................................................ 317
Spare tire............................................... 560
Tire inflation pressure display function................................................ 492
Tire pressure warning system ..... 492
Warning light .......................................535
T