Page 497 of 660

4977-3. Do-it-yourself maintenance
7
Maintenance and care
IS350 AWD/IS350/IS300 AWD/IS300_U
■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 properly 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.
WARNING
■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 resu lting 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 a valve cap is not installed, dirt or moisture may get into the valve and cause an air
leak, resulting in decreased tire inflation pressure.
Page 500 of 660
5007-3. Do-it-yourself maintenance
IS350 AWD/IS350/IS300 AWD/IS300_U
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 ch anged regularly to maintain air condi-
tioning efficiency.
Removal method
1
2
3
4
Page 501 of 660

5017-3. Do-it-yourself maintenance
7
Maintenance and care
IS350 AWD/IS350/IS300 AWD/IS300_U
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 cond itioning filter according to the maintenance schedule. In
dusty areas or areas with heavy traffic fl ow, 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.
■Air conditioning filter with deodorizing function
When fragrances are placed in your vehicle, the deodorizing effect may become signifi-
cantly weakened in a short period.
When an air conditioning odor comes out cont inuously, replace the air conditioning filter.
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 523 of 660
5238-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
●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 529 of 660

5298-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
■Electric power steering system warning light (warning buzzer)
When the battery charge becomes insufficien t or the voltage temporarily drops, the
electric power steering system warning li ght may come on and the warning buzzer may
sound.
■When the tire pressure warning light comes on
Check the tire inflation pressu re and adjust to the appropriate level. Pushing the tire
pressure warning reset switch will not turn off the tire pressure warning light.
■The tire pressure warning light ma y 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 caus ed 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 wa rning system may not function properly
P. 490
■If the tire pressure warning light freque ntly 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.
WARNING
■If both the ABS and the brake system warning lights remain on
Stop your vehicle in a safe place immediat ely and contact your Lexus dealer. The vehi-
cle will become extremely unstable during braking, and the ABS system may fail, which
could cause an accident resultin g in death or serious injury.
■When the electric power steering system warning light comes on
The steering wheel may become extremely heavy.
When steering wheel operations are heavier than usual, grip the steering wheel firmly
and operate it using more force than usual.
■If the tire pressure warning light comes on
Be sure to observe the following precaution s. Failure to do so could cause a loss of
vehicle control and result in death or serious injury.
●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 adjust-
ment, it is probable that you have a flat tire . Check the tires. If a tire is flat, change it
with 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.
Page 551 of 660
5518-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
*: Refer to the separate “Scheduled Maintenance” or “Owner’s Manual Supplement”
for the maintenance interval applicable to your vehicle.
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 consumpt ion. Wait a while until
the electric power supply is restored.
If this message is freque ntly displayed, have the
vehicle inspected at your Lexus dealer immediately.
Indicates that part of th e PCS (Pre-Collision System)
sensor is dirty, covered with ice, etc.
Remove any dirt, ice, etc.
Warning messageDetails/Actions
(Flashes)
Page 579 of 660
5798-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
●The needle of the engine coolant temperature gauge (P. 89) enters the red
zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display.
●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, insp ect 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
Page 581 of 660

5818-2. Steps to take in an emergency
8
When trouble arises
IS350 AWD/IS350/IS300 AWD/IS300_U
Add coolant if necessary.
Water can be used in an emergency if coolant is unavailable.
Start the engine and turn the air conditio ning system on to check that the radi-
ator cooling fans operate and to check for coolant leaks from the radiator or
hoses.
The fans operate when the air conditioning system is turned on immediately after a
cold start. Confirm that the fans are operating by checking the fan sound and air flow.
If it is difficult to check these, turn the air conditioning system on and off repeatedly.
(The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately an d contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
Check if “Engine Coolant Temp High St op in a Safe Place See Owner’s Man-
ual” is shown on the multi-information display.
If the message does not disappear:
Stop the engine and contact your Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the nearest Lexus dealer.
5
Engine (IS350 AWD/IS350/
IS300 AWD)Engine (IS300)
Intercooler (IS300)
6
7
8