warning Lexus IS250C 2014 Repair Manual

5
When trouble arises
497
5-2. Steps to take in an emergency
IS250C/350C_U
■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.

498
5-2. Steps to take in an emergency
IS250C/350C_U
CAUTION
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold
and inflated to the inflation pressure recommended by the vehicle manufacturer on
the vehicle placard or tire inflation pressure label (tire and load information label).
(If your vehicle has tires of a different size than the size indicated on the vehicle
placard or tire inflation pressure label [tire and load information label], you should
determine the proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle has been equipped with a tire pressure
monitoring system (TPMS-tire pressure warning system) that illuminates a low tire
pressure telltale (tire pressure warning light) when one or more of your tires is sig-
nificantly under-inflated. Accordingly, when the low tire pressure telltale (tire pres-
sure warning light) illuminates, you should stop and check your tires as soon as
possible, and inflate them to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat and can lead to tire failure. Under-inflation
also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling
and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a substitute for
proper tire maintenance, and it is the driver's responsibility to maintain correct tire
pressure, even if under-inflation has not reached the level to trigger illumination of
the TPMS low tire pressure telltale (tire pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system)
malfunction indicator to indicate when the system is not operating properly. The
TPMS (tire pressure warning system) malfunction indicator is combined with the
low tire pressure telltale (tire pressure warning light). When the system detects a
malfunction, the telltale will flash for approximately one minute and then remain
continuously illuminated. This sequence will continue upon subsequent vehicle
start-ups as long as the malfunction exists. When the malfunction indicator is illumi-
nated, the system may not be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a variety of rea-
sons, including the installation of replacement or alternate tires or wheels on the
vehicle that prevent the TPMS (tire pressure warning system) from functioning
properly. Always check the TPMS (tire pressure warning system) malfunction tell-
tale after replacing one or more tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow the TPMS (tire pressure warning
system) to continue to function properly.

500
5-2. Steps to take in an emergency
IS250C/350C_U
If a warning message is displayed
Stop the vehicle immediately.
A buzzer sounds and a warning message is shown on the multi-informa-
tion display. The following warnings indicate the possibility of damage to
the vehicle that may lead to an accident. Immediately stop the vehicle in a
safe place and contact your Lexus dealer.
MessageDetails
(U.S.A)
(Canada) (Flashing)Indicates an abnormal engine oil pressure.The warning light may turn on if the engine oil pres-
sure is too low.
If a warning is shown on the multi-information display, stay calm and per-
form the following actions:
Master warning light
The master warning light also
comes on or flashes in order to
indicate that a message is cur-
rently being displayed on the
multi-information display.
Multi-information display
If any of the warning lights turns on again after performing the follow-
ing actions, contact your Lexus dealer.

5
When trouble arises
509
5-2. Steps to take in an emergency
IS250C/350C_U
*: Refer to the separate “Scheduled Maintenance” or “Owner’s Manual Supple-ment” for the maintenance interval applicable to your vehicle.
(Flashing
quickly)
(If equipped)
Indicates that there is a
high possibility of a fron-
tal collision, or that the
pre-collision braking
function is operating.
Slow the vehicle by apply-
ing the brakes.
■Warning light display in dynamic radar cruise mode (if equipped)
In the following cases, the warning light may not be displayed even if vehicle-to-
vehicle distance closes.
●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
MessageDetailsCorrection procedure

510
5-2. Steps to take in an emergency
IS250C/350C_U
Follow the correction procedures.After taking the specified steps to correct the suspected problem, check
that the warning light turns off.
InteriorbuzzerExterior buzzerMessageDetailsCorrection
procedure
Once
(Comes on for 10 seconds.)
(Flashing)
Indicates that an
attempt was made
to start the engine
without the elec-
tronic key being
present, or the
electronic key was
not functioning
normally.
Start the engine
with the elec-
tronic key
present.
*
Once3 times
(Flashing)
Indicates that a
door other than
the driver’s door
has been opened
or closed with the
“ENGINE START
STOP” switch in
any mode other
than OFF and the
electronic key
outside of the
detection area.
Confirm the loca-
tion of the elec-
tronic key.

518
5-2. Steps to take in an emergency
IS250C/350C_U
■The compact spare tire
●The compact spare tire is identified by the label “TEMPORARY USE ONLY”
on the tire sidewall.
Use the compact spare tire temporarily only in an emergency.
●Make sure to check the tire pressure of the compact spare tire. (→P. 5 6 3 )
■When using the compact spare tire
As the compact spare tire is not equipped with the tire pressure warning valve and
transmitter, low inflation pressure of the spare tire will not be warned. Also, if you
replace the compact spare tire after the tire pressure warning light comes on, the
light remains on.
■If you have a flat rear tire on a road covered with snow or ice
Install the compact spare tire on the front of the vehicle. Perform the following steps
and fit tire chains to the rear tires.
Replace a front tire with the compact spare tire.
Replace the flat rear tire with the tire removed from the front of the vehi-
cle.
Fit tire chains to the rear tires.
■After completing the tire change
The tire pressure warning system must be reset. ( →P. 4 3 2 )
STEP1
STEP2
STEP3

5
When trouble arises
521
5-2. Steps to take in an emergency
IS250C/350C_U
NOTICE
■Do not drive the vehicle with a flat tire.
Do not continue driving with a flat tire.
Driving even a short distance with a flat tire can damage the tire and the wheel
beyond repair.
■Be careful when driving over bumps with the compact spare tire installed on the
vehicle.
The vehicle becomes lower when driving with the compact spare tire compared to
when driving with standard tires. Be careful when driving over uneven road sur-
faces.
■Driving with tire chains and the compact spare tire
Do not fit tire chains to the compact spare tire.
Tire chains may damage the vehicle body and adversely affect driving performance.
■When replacing the tires
When removing or fitting the wheels, tires or the tire pressure warning valve and
transmitter, contact your Lexus dealer as the tire pressure warning valve and trans-
mitter may be damaged if not handled correctly.
■To avoid damage to the tire pressure warning valves and transmitters
When a tire is repaired with liquid sealants, the tire pressure warning valve and
transmitter may not operate properly. If a liquid sealant is used, contact your Lexus
dealer or other qualified service shop as soon as possible. Make sure to replace the
tire pressure warning valve and transmitter when replacing the tire. (→P. 4 3 2 )

522
5-2. Steps to take in an emergency
IS250C/350C_U
If you have a flat tire (vehicles with run-flat tires)
■In some condition (such as at high temperatures)
You cannot continue driving for up to 100 miles (160 km).
■If you cannot distinguish between the standard tires and run-flat tires
Consult your Lexus dealer.
■Spare tire
A spare tire is not provided on the vehicle with run-flat tires.
■For the detailed information on run-flat tires
See the tire warranty book.
Take your vehicle to the nearest Lexus dealer or authorized tire dealer as
soon as possible.
■Run-flat tires (A “RFT” or “DSST” mark is molded on the sidewall)
You can continue driving a vehi-
cle with run-flat tires even if any
tire goes flat.
It is able to run for a maximum of
100 miles (160 km) at a speed
below 50 mph (80 km/h) after
the tire pressure warning light
comes on. (→ P. 4 9 3 )

5
When trouble arises
523
5-2. Steps to take in an emergency
IS250C/350C_U
NOTICE
■When replacing the tires
When removing or fitting the wheels, tires or the tire pressure warning valve and
transmitter, contact your Lexus dealer as the tire pressure warning valve and trans-
mitter may be damaged if not handled correctly.
■To avoid damaging the tire pressure warning valves and transmitters
When a tire is repaired with the emergency tire puncture repair kit, the tire pressure
warning valve and transmitter may not operate properly. If the emergency tire
puncture repair kit is used, replace the tire pressure warning valve and transmitter
when replacing the tire.

578
6-1. Specifications
IS250C/350C_U■
DOT quality grades
All passenger vehicle tires must conform to Federal Safety Require-
ments in addition to these grades. Quality grades can be found where
applicable on the tire sidewall between tread shoulder and maximum
section width.
For example: Treadwear 200 Traction AA Temperature A
■Treadwear
The treadwear grade is a comparative rating based on the wear rate of
the tire when tested under controlled conditions on a specified gov-
ernment test course.
For example, a tire graded 150 would wear one and a half (1 - 1 /2) times as
well on the government course as a tire graded 100.
The relative performance of tires depends upon the actual conditions of
their use, however, and may depart significantly from the norm due to varia-
tions in driving habits, service practices and differences in road characteris-
tics and climate.
■Traction AA, A, B, C
The traction grades, from highest to lowest, are AA, A, B and C, and
they represent the tire's ability to stop on wet pavement as measured
under controlled conditions on specified government test surfaces of
asphalt and concrete.
A tire marked C may have poor traction performance.
Warning: The traction grade assigned to this tire is based on braking
(straight ahead) traction tests and does not include cornering (turning) trac-
tion.