Page 529 of 692

5297-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
■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 th at 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.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects th e radio wave signals is installed. • If there is a lot of snow or ice on the vehi cle, 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 that generates strong radio waves or electrical noise
• When carrying a portable ra dio, 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
●Make sure to carry out init ialization after adjusting the tire inflation pressure.
Also, make sure the tires are cold before carr ying out initialization or tire inflation pres-
sure adjustment.
●If you have accidentally turned the power switch off during initialization, it is not neces- sary to press the reset switch again as initialization will restart automatically when the
power switch has been turned to ON mode for the next time.
●If you accidentally press the reset switch when initialization is not necessary, adjust the tire inflation pressure to th e specified level when the tires are cold, and conduct initial-
ization again.
■Warning performance of the tire pressure warning system
The warning of the tire pressu re warning system will change in accordance with the con-
ditions 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.
Page 530 of 692

5307-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
■When initialization of the tire pressure warning system has failed
Initialization can be completed in a few minute s. 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 any authorized Le xus retailer or Lexus authorized repairer, or any reliable repairer.
●When operating the tire pre ssure warning reset switch, the tire pressure warning light
does not blink 3 times.
●After carrying out the initializat ion procedure, the tire pressure warning light blinks for 1
minute then stays on after driving for 20 minutes.
■Registering ID codes
The ID codes of the tire pressure warning valve and transmitters for two sets of wheels
can be registered.
It is not necessary to register the ID codes wh en replacing normal tires with snow tires, if the ID codes for the wheels of both normal tires and snow tires are registered before-
hand.
For information about changing ID codes, as k any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer.
Page 531 of 692
5317-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
■Certification for tire pressure warning system
Page 532 of 692
5327-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
Page 533 of 692
5337-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
Page 534 of 692
5347-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
Page 535 of 692

5357-3. Do-it-yourself maintenance
7
Maintenance and care
IS300h_EE(OM53D89E)
WARNING
■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 ma y 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 re markably 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 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 unexpe cted 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 spec ified 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.
Page 536 of 692

5367-3. Do-it-yourself maintenance
IS300h_EE(OM53D89E)
NOTICE
■Repairing or replacing tires, wheels, tire pressure warning valves, transmitters and tire valve caps
●When removing or fitting the wheels, tires or the tire pressure warning valves and
transmitters, contact any authorized Lexus retailer or Lexus authorized repairer, or any reliable repairer as the tire pressure warning valves and transmitters may be dam-
aged if not handled correctly.
●Make sure to install the tire valve caps. If the tire valve caps are not installed, water could enter the tire pressure warning valv es and the tire pressure warning valves
could be bound.
●When replacing tire valve caps, do not use tire valve caps other than those specified. The cap may become stuck.
■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 trans- mitter may not operate properly. If a liqui d sealant is used, contact any authorized
Lexus retailer or Lexus authoriz ed repairer, or any reliable repairer or other qualified
service shop as soon as possible. After use of liquid sealant, make sure to replace the tire pressure warning valve and transmitter when repairing or replacing the tire.
( P. 526)
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause lo sses in tire inflation pressure, reducing the cushioning
ability of the tires. In addition, driving on rough roads may cause damage to the tires themselves, as well as the vehicle’s wheels and body.
■Low profile tires (except 16-inch tires)
Low profile tires may cause greater damage than usual to the tire wheel when sustain- ing impact from the road surface. Ther efore, pay attention to the following:
●Be sure to use proper tire inflation pressure. If tires are under-inflated, they may be
damaged more severely.
●Avoid potholes, uneven pavement, curbs an d other road hazards. Failure to do so
may lead to severe tire and wheel damage.
■If tire inflation pressure of ea ch tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.