Page 431 of 584

4317-3. Do-it-yourself maintenance
7
Maintenance and care
IS350/250_U (OM53C50U)
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 your Lexus dealer as the tire pressure warning valves and trans-
mitters may be damaged 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 valves 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 pressu re 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 liquid se alant 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 2 4 )
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause losses 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 and other road hazards. Failure to do so
may lead to severe tire and wheel damage.
■If tire inflation pressure of each tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.
Page 434 of 584

4347-3. Do-it-yourself maintenance
IS350/250_U (OM53C50U)
■Instructions for checking tire inflation pressure
When checking tire inflation pressure, observe the following:
●Check only when the tires are cold.
If your vehicle has been parked for at least 3 hours or has not been driven for more than
1 mile or 1.5 km, you will get an accurate cold tire inflation pressure reading.
●Always use a tire pressure gauge.
It is difficult to judge if a tire is pro perly inflated based only on its appearance.
●It is normal for the tire inflation pressure to be higher after driving as heat is generated
in the tire. Do not reduce tire inflation pressure after driving.
●Never exceed the vehicle capacity weight.
Passengers and luggage weight should be placed so that the vehicle is balanced.
CAUTION
■Proper inflation is critical to save tire performance
Keep your tires properly inflated.
If the tires are not properly inflated, the following conditions may occur which could
lead to an accident resulting in death or serious injury:
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts result ing from overheated tires
●Air leaking from between tire and wheel
●Wheel deformation and/or tire damage
●Greater possibility of tire damage while driving (due to road hazards, expansion
joints, sharp edges in the road, etc.)
NOTICE
■When inspecting and adjust ing tire inflation pressure
Be sure to put the tire valve caps back on.
If the valve caps are not insta lled, dirt or moisture may get into the valve and cause air
leakage, which could result in a flat tire.
Page 437 of 584
4377-3. Do-it-yourself maintenance
7
Maintenance and care
IS350/250_U (OM53C50U)
Turn the engine switch off.
Open the glove box. Lift up the side
with the stay, disconnect the stay
tabs and remove the partition by
pulling horizontally.
Press the tabs and remove the filter
cover.
Press the tabs and remove the filter
case.
Air conditioning filter
The air conditioning filter must be changed regularly to maintain air condi-
tioning efficiency.
Removal method
1
2
3
4
Page 438 of 584
4387-3. Do-it-yourself maintenance
IS350/250_U (OM53C50U)
Remove the air conditioning filter
from the filter case and replace it
with a new one.
The “ UP” marks shown on the filter
and the filter case should be pointing up.
■Checking interval
Inspect and replace the air conditioning filt er according to the maintenance schedule. In
dusty areas or areas with heavy traffic flow, early replacement may be required. (For
scheduled maintenance informat ion, please refer to the “Owner’s Manual Supplement”
or “Scheduled Maintenance”.)
■If air flow from the vents decreases dramatically
The filter may be clogged. Check the filter and replace if necessary.
5
NOTICE
■When using the air conditioning system
Make sure that a filter is always installed.
Using the air conditioning system without a filter may cause damage to the system.
Page 464 of 584
4648-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
●Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
●Flat-looking tires or uneven tire wear
●Engine coolant temperature gauge needle continually points higher than nor-
mal.
●Changes in exhaust sound
●Excessive tire squeal when cornering
●Strange noises related to the suspension system
●Pinging or other noises related to the engine
●Engine missing, stumbling or running roughly
●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, spongy feeling, pedal almost touches the floor
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
Audible symptoms
Operational symptoms
Page 469 of 584

4698-2. Steps to take in an emergency
8
When trouble arises
IS350/250_U (OM53C50U)
■SRS warning light
This warning light system monitors the airbag sensor assembly, front impact sensors, side
impact sensors (front door), side impact sensors (front), side impact sensors (rear),
driver’s seat position sensor, driver’s seat belt buckle switch, front passenger occupant
classification system, “AIR BAG ON” indica tor light, “AIR BAG OFF” indicator light,
front passenger’s seat belt buckle switch, seat belt pretensioner assemblies, airbags,
interconnecting wiring and power sources. ( P. 3 8 )
■Front passenger detection sensor, 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 wa rning buzzer to sound even if a passenger
is not sitting in the seat.
■If the malfunction indicator lamp comes on while driving
First check the following:
●Is the fuel tank empty?
If it is, fill the fuel tank immediately.
●Is the fuel tank cap loose?
If it is, tighten it securely.
The light will go off after several driving trips.
If the light does not go off even after severa l trips, contact your Lexus dealer as soon as
possible.
■Electric power steering system warning light (warning buzzer)
When the battery charge becomes insufficie nt of the voltage temporarily drops, the
electric power steering system warning light may come on and the warning buzzer may
sound.
■When the tire pressure warning light comes on
Check the tire inflation pressure and adjust to the appropriate level. Pushing the tire
pressure warning reset switch will not tu rn off the tire pressure warning light.
■The tire pressure warning light may come on due to natural causes
The tire pressure warning light may come on due to natural causes such as natural air
leaks and tire inflation pressure changes caused by temperature. In this case, adjusting
the tire inflation pressure will turn off the warning light (after a few minutes).
■When a tire is replaced with the spare tire
The compact spare tire is not equipped with a tire pressure warning valve and transmit-
ter. If a tire goes flat, the tire pressure warning light will not turn off even though the flat
tire has been replaced with the spare tire.
■Conditions that the tire pressure warning system may not function properly
P. 4 2 8
■If the tire pressure warning light frequently comes on after blinking for 1 minute
If the tire pressure warning light frequently comes on after blinking for 1 minute when the
engine switch is turned to IGNITION ON mo de, have it checked by your Lexus dealer.
■Warning buzzer
In some cases, the buzzer may not be heard due to being in a noisy location or audio
sound.
Page 480 of 584

4808-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
*: Refer to the separate “Scheduled Maintenance” or “Owner’s Manual Supplement”
for the maintenance interval applicable to your vehicle.
(U.S.A. only)
Indicates that all maintenance is required to correspond
to the driven distance on the maintenance schedule*.
Comes on approximately 5000 miles (8000 km) after
the maintenance data has been reset.
(The indicator will not work properly unless the mainte-
nance data has been reset.)
Perform the necessary maintenance. Please reset
the maintenance data afte r the maintenance is per-
formed ( P. 4 0 3 )
(If equipped)
Indicates that the Automatic High Beam switch is
pressed while the headlights are in low beam.
Turn the high beam on and press the Automatic
High Beam switch again.
(If equipped)
Indicates that, since the VSC (Vehicle Stability Control)
system was turned off, the pre-collision brake system
operation is stopped
Turn the VSC on. ( P. 2 4 2 )
(If equipped)
Indicates that the PCS (Pre-Collision System) is not cur-
rently functional because the grille cover or the sensor is
dirty
Check the grille cover and the sensor and clean
them if they are dirty.
Indicates that operation of large electricity consuming
systems such as the air conditioning system are sus-
pended
Stop using unnecessary electric components to
reduce electricity consumption. Wait a while until
the electric power supply is restored.
(If equipped)
Indicates that the LDA (Lane Departure Alert) system
cannot be used because the vehicle speed is lower than
approximately 32 mph (50 km/h)
Drive the vehicle at 32 mph (50 km/h) or higher.
Wa r n i n g m e s s a g eDetails/Actions
(Flashes)
Page 506 of 584
5068-2. Steps to take in an emergency
IS350/250_U (OM53C50U)
●The needle of the engine coolant temperature gauge (P. 81) enters the red
zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●Steam comes out from under the hood.
Stop the vehicle in a safe place and tu rn off the air conditioning system, and
then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down
sufficiently, inspect the hoses and
radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2