maintenance Lexus GS250 2012 Service Manual

6746-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)Your vehicle is equipped with a tire pressure warning system that
uses tire pressure warning valves and transmitters to detect low tire
inflation pressure before serious problems arise.
Vehicles without the tire inflation pressure display function
If the tire pressure drops below a predetermined level, the driver is
warned by a warning light. (P. 753)
Vehicles with the tire inflation pressure display function
If the tire pressure drops below a predetermined level, the driver
is warned by a screen display and a warning light. (P. 772)
The tire pressure detected by the tire pressure warning system
can be displayed on the multi-information display. (P. 106)
Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and
transmitters must also be installed.
When new tire pressure warning valves and transmitters are
installed, new ID codes must be registered in the tire pressure
warning computer and the tire pressure warning system must be
initialized. Have tire pressure warning valve and transmitter ID
codes registered by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional. (P. 676)
Tire pressure warning system (if equipped)

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Maintenance and care
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Initializing the tire pressure warning system
The tire pressure warning system must be initialized in the fol-
lowing circumstances:
When rotating the tires.
When the tire inflation pressure is changed such as when
changing traveling speed.
When the tire pressure warning system is initialized, the current
tire inflation pressure is set as the benchmark pressure.
How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the engine switch off.
Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire infla-
tion pressure level. (P. 850)
Make sure to adjust the tire pressure to the specified cold tire inflation
pressure level. The tire pressure warning system will operate based on
this pressure level.
Turn the engine switch to IGNITION ON mode.
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2
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6766-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)Press and hold the tire pres-
sure warning reset switch
until the tire pressure warn-
ing light blinks slowly 3
times.
Wait for a few minutes with the engine switch in IGNITION
ON mode and then turn the engine switch off.
Registering ID codes
The tire pressure warning valve and transmitter is equipped with
a unique ID code. When replacing a tire pressure warning valve
and transmitter, it is necessary to register the ID code. Have the
ID code registered by any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
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Maintenance and care
GS350/250_EE (OM30C36E)
When to replace your vehicle’s tires
Tires should be replaced if:
You have tire damage such as cuts, splits, cracks deep enough to expose the
fabric, and bulges indicating internal damage
A tire goes flat repeatedly or cannot be properly repaired due to the size or
location of a cut or other damage
If you are not sure, consult with any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Replacing tires and wheels (vehicles with the tire pressure warning system)
If the ID code of the tire pressure warning valve and transmitter is not regis-
tered, the tire pressure warning system will not work properly. After driving
for about 10 minutes, the tire pressure warning light blinks for 1 minute and
stays on to indicate a system malfunction.
Tire life
Any tire over 6 years old must be checked by a qualified technician even if it
has seldom or never been used or damage is not obvious.
Routine tire inflation pressure checks
The tire pressure warning system does not replace routine tire inflation pres-
sure checks. Make sure to check tire inflation pressure as part of your routine
of daily vehicle checks.
When rotating the tires (vehicles with the tire pressure warning system featur-
ing a tire inflation pressure display function)
Make sure that the engine switch is off. If the tires are rotated while the
engine switch is in IGNITION ON mode, the tire position information will
not be updated.
If this accidentally occurs, either turn the engine switch to off and then to
IGNITION ON mode, or initialize the system after checking that the tire
pressure is properly adjusted.

6786-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
Low profile tires (except 225/50R17 tires)
Generally, low profile tires will wear more rapidly and tire grip performance
will be reduced on snowy and/or icy roads when compared to standard tires.
Be sure to use snow tires or tire chains
* on snowy and/or icy roads and drive
carefully at a speed appropriate for road and weather conditions.
*: Tire chains cannot be mounted on the 19-inch tires. Snow tires should be
used instead.
If the tread on snow tires wears down below 4 mm (0.16 in.)
The effectiveness of the tires as snow tires is lost.
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
properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equip-
ment) 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 the spare tire is in a location subject to poor radio wave signal recep-
tion.
*
• If a large metallic object which can interfere with signal reception is put
in the trunk.
*
*
: Vehicles with a full-size spare tire only
Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large
display, airport or other facility that generates strong radio waves or elec-
trical noise
• When carrying a portable radio, cellular phone, cordless phone or other
wireless communication device
Vehicles with the tire inflation pressure display function: If tire position
information is not correctly displayed due to the radio wave conditions, the
display may be corrected by driving and changing the radio wave condi-
tions.

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Maintenance and care
GS350/250_EE (OM30C36E)
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.

6806-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
The initialization operation (vehicles with the tire pressure warning system)
Make sure to carry out initialization after adjusting the tire inflation pres-
sure.
Also, make sure the tires are cold before carrying out initialization or tire
inflation 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
automatically 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 neces-
sary, 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.
When initialization of the tire pressure warning system has failed (vehicles
with the tire pressure warning system)
Initialization can be completed in a few minutes. However, in the following
cases, the settings 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 Lexus dealer or
repairer, or another duly qualified and equipped professional.
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 10 minutes.

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Maintenance and care
GS350/250_EE (OM30C36E)
Certification for tire pressure warning system (vehicles with the tire pressure
warning system)

6826-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)

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Maintenance and care
GS350/250_EE (OM30C36E)