Lexus 2013 IS250 Owner's Manual page 444


Situations in which the tire pressure warning system may not operate properly
(vehicles with the tire pressure warning system)

In the following cases, the tire pressure warning system may not operate prop-
erly.
• 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 reg-
istered 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 dis-
play, airport or other facility that generates strong radio waves or electrical
noise
• When carrying a portable radio, cellular phone, cordless phone or other
wireless communication device

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 (vehicles with the tire pressure warning system)

Make sure to carry out initialization after adjusting the tire inflation pressure.
Also, make sure the tires are cold before carrying out initialization or tire infla-
tion pressure adjustment.

If you have accidentally turned the engine switch off during initialization, it is
not necessary to press the reset switch again as initialization will restart auto-
matically when the engine switch has been turned to IGNITION 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 cold,
and conduct initialization again.

Warning performance of the tire pressure warning system (if equipped)
The warning of the tire pressure warning system will change in accordance with
the conditions under which it was initialized. For this reason, the system may
give a warning even if the tire pressure does not reach a low enough level, or if
the pressure is higher than the pressure that was adjusted to when the system was
initialized.
IS250_EE(OM53B11E)
7-3. Do-it-yourself maintenance
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