2012 Lexus IS250C flat tire

452
4-3. Do-it-yourself maintenance
CAUTION
■When replacing wheels
●Do not use wheels that are a different size from those recommended in the
Owner’s Manual, as this may result in loss of handling control.
●Never use an inner tube in a leaking wheel which is designed for a tubeless tire.
Doing so may result in an accident, causing death or serious injury.
NOTICE
■Replacing tire inflation pressure warning valves and transmitters
●Because tire repair or replacement may affect the tire pressure warning valves
and transmitters, make sure to have tires serviced by your Lexus dealer or other
qualified service shop. In addition, make sure to purchase your tire pressure
warning valves and transmitters at your Lexus dealer.
●Ensure that only genuine Lexus wheels are used on your vehicle.
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.

468
4-3. Do-it-yourself maintenance
10ECU-IG LH10 A
Cruise control, air conditioning sys-
tem, power steering, rain sensor, anti-
glare inside rear view mirror, shift lock
system, tire inflation pressure warning
system, vehicle stability control
11FR S/HTR LH15 ASeat heaters and ventilators, air condi-
tioning system
12FR DOOR LH20 APower windows, outside rear view
mirrors
13SECURITY7. 5 ASmart access system with push-button
start
14H-LP LVL7. 5 AAutomatic head light leveling system
15LH-IG10 A
Charging system, headlight cleaner,
rear window defogger, electric cool-
ing fans, emergency flashers, turn sig-
nal lights, back-up lights, stop lights,
mirror heaters, seat belt pretensioner,
intuitive parking assist, cruise control,
PTC heater, exhaust system, smart
access system with push-button start
16FR WIP30 AWindshield wipers
FuseAmpereCircuit

When trouble arises5
485
5-1. Essential informationEmergency flashers............... 486
If your vehicle needs to be towed................................. 487
If you think something is wrong .................................. 493
Fuel pump shut off system.... 494 5-2. Steps to take in an
emergency
If a warning light turns on or a warning buzzer
sounds... ................................. 495
If a warning message is displayed................................ 504
If you have a flat tire (vehicles with standard
tires) ......................................... 518
If you have a flat tire (vehicles with run-flat
tires) ........................................ 527
If the engine will not start .... 529
If the shift lever cannot be shifted from P .................. 531
If you lose your keys .............. 532
If the electronic key does not operate properly.......... 533
If the vehicle battery is discharged......................... 538
If your vehicle overheats ..... 542
If the vehicle becomes stuck........................................ 545
If the retractable hardtop does not close ...................... 547
If your vehicle has to be stopped in an
emergency ............................ 557

5
When trouble arises
493
5-1. Essential information
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs
adjustment or repair. Contact your Lexus dealer as soon as possible.
■Visible symptoms
●Fluid leaks under the vehicle
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or uneven tire wear
● Engine coolant temper ature gauge needle continually points
higher than normal
■ Audible symptoms
●Changes in exhaust sound
● Excessive tire squeal when cornering
● Strange noises related to the suspension system
● Pinging or other noises related to the engine
■ Operational symptoms
●Engine missing, stumbling or running rough
● Appreciable loss of power
● Vehicle pulls heavily to one side when braking
● Vehicle pulls heavily to one side when driving on a level road
● Loss of brake effectiveness, sp ongy feeling, pedal almost touches
the floor

498
5-2. Steps to take in an emergency
*1:Open door warning buzzer
P. 5 0 7
*2:Driver's and front passenger’s seat belt reminders buzzer
The driver’s and front passenger’s seat belts reminder sounds to alert the driver
and front passenger that his or her seat belt is not fastened. The buzzer sounds
intermittently for 10 seconds after the vehicle has reached a speed of at least 12
mph (20 km/h). Then, if the seat belt is still unfastened, the buzzer will sound in a
different tone for 20 more seconds.
Tire pressure warning light
When the light comes on:
Low tire inflation pressure
such as
• Natural causes ( P. 500)
• Flat tire ( P. 5 1 8 , 5 2 7 )
Adjust the tire inflation pres-
sure to the specified level.
The light will turn off after a
few minutes. In case the light
does not turn off even if the
tire inflation pressure is
adjusted, have the system
checked by your Lexus
dealer.
When the light comes on after
blinking for 1 minute:
Malfunction in the tire pres-
sure warning system
( P. 5 0 0 )
Have the system checked by
your Lexus dealer.
Master warning light
A buzzer sounds and the
warning light comes on and
flashes to indicate that the
master warning system has
detected a malfunction.
 P. 5 0 4
Warning lightWarning light/DetailsCorrection procedure

5
When trouble arises
499
5-2. Steps to take in an emergency
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The lamp will go off after taking several driving trips.
If the lamp does not go off even after several trips, contact your Lexus dealer as
soon as possible.
■Electric power steering system warning light
When the voltage is low or drops, the electric power steering system warning light
may come on.
■Front passenger detection se nsor and passenger 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 warning buzzer to sound,
even if a passenger is not sitting in the seat.
●If a cushion is placed on the seat, the sensor may not detect a passenger, and the
warning light may not operate properly.
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pressing the
satellite switch does not turn off the tire pressure warning light.

500
5-2. Steps to take in an emergency
■The tire pressure warning light may turn on due to natural causes
The tire pressure warning light may turn on due to natural causes such as natural air
leaks or tire inflation pressure changes caused by temperature. In this case, adjust-
ing the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with a spare tire (vehicles with a spare tire)
The compact spare tire is not equipped wi th the tire pressure warning valve and
transmitter. If a tire goes flat, the tire pressure warning light will not turn off even
though the flat tire is replaced with the spare tire. Replace the spare tire with the
repaired tire and adjust the proper tire inflation pressure. The tire pressure warning
light will turn off after a few minutes.
■If the tire pressure warning system is inoperative
The tire pressure warning system will be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●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 regis-
tered in the tire pressure warning computer
●If a different set of tires has been selected using the satellite switch.
●If the tire inflation pressure is 73 psi (500 kPa, 5.1 kgf/cm2 or bar) or higher
The tire pressure warning system may be disabled in the following conditions:
(When the condition becomes normal, the system will work properly.)
●If electronic devices or facilities using similar radio wave frequencies are nearby
●If a radio set at similar frequencies is in use in the vehicle
●If there is a lot of snow or ice on the vehicle, in particular around the wheels or
wheel housings
●If non-genuine Lexus wheels are used (Even if you use Lexus wheels, the tire
pressure warning system may not work properly with some types of tires.)
●If tire chains are used
■If the tire pressure warning light freque ntly comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute
when the “ENGINE START STOP” switch is turned to IGNITION ON mode, have
it checked by your Lexus dealer.

5
When trouble arises
501
5-2. Steps to take in an emergency
■If the open retractable hardtop warning buzzer sounds
Immediately stop the vehicle in a safe place and open or close the retractable hard-
top fully.
CAUTION
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
If the steering wheel becomes heavier than usual when operating, hold firmly and
operate using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precautions. Failure to do so could cause loss of
vehicle control and result in death or serious injury.
Vehicles with run-flat tires
• Decelerate to the lowest appropriate speed as soon as possible. Do not drive over 50 mph (80 km/h).
• Check and adjust the tire inflation pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure
adjustment, it is probable that you have a flat tire. Have the tire replaced by
the nearest Lexus dealer.
• Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
Vehicles with standard tires
• Stop your vehicle in a safe place as soon as possible. Adjust the tire inflation pressure immediately.
• If the tire pressure warning light comes on even after tire inflation pressure adjustment, it is probable that you have a flat tire. Check the tires. If the tire is
flat, change to the spare tire and have the flat tire repaired by the nearest
Lexus dealer.
• Avoid abrupt maneuvering and braking. If the vehicle tires deteriorate, you
could lose control of the steering wheel or the brakes.
■If a blowout or sudden air leakage should occur
The tire pressure warning system may not activate immediately.