
580 7-3. Do-it-yourself maintenance
RX350_U_OM48E90U ■
Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■
Adding fluid
Make sure to check the fluid type and prepare the necessary item. ■
Brake fluid can absorb moisture from the air
Excess moisture in the brake fluid can cause a dangerous loss of braking efficiency. Use
only newly opened brake fluid.Brake fluid
Fluid type FMVSS No.116 DOT 3 or SAE J1703 brake fluid
Items Clean funnel
WA R N I N G ■
When filling the reservoir
Take care as brake fluid can harm your hands and eyes and damage painted surfaces.
If fluid gets on your hands or in your eyes, flush the affected area with clean water
immediately.
If you still experience discomfort, see a doctor.
NOTICE ■
If the fluid level is low or high
It is normal for the brake fluid level to go down slightly as the brake pads wear out or
when the fluid level in the accumulator is high.
If the reservoir needs frequent refil ling, there may be a serious problem.

582 7-3. Do-it-yourself maintenance
RX350_U_OM48E90U WA R N I N G ■
Chemicals in the battery
Battery contains poisonous and corrosive sulfuric acid and may produce hydrogen gas
which is flammable and explosive. To reduce th e risk of death or se rious injury, take the
following precautions while working on or near the battery: ●
Do not cause sparks by touching the battery terminals with tools. ●
Do not smoke or light a match near the battery. ●
Avoid contact with eyes, skin and clothes. ●
Never inhale or swallow electrolyte. ●
Wear protective safety glasses when working near the battery.●
Keep children away from the battery. ■
Where to safely charge the battery
Always charge the battery in an open area. Do not charge the battery in a garage or
closed room where there is insufficient ventilation. ■
How to recharge the battery
Only perform a slow charge (5 A or less). The battery may explode if charged at a
quicker rate. ■
Emergency measures regarding electrolyte ●
If electrolyte gets in your eyes
Flush your eyes with clean water for at least 15 minutes and get immediate medical
attention. If possible, continue to apply water with a sponge or cloth while traveling to
the nearest medical facility. ●
If electrolyte gets on your skin
Wash the affected area thoroughly. If you fe el pain or burning, get medical attention
immediately. ●
If electrolyte gets on your clothes
It can soak through clothing on to your skin. Immediately take off the clothing and fol-
low the procedure above if necessary. ●
If you accidentally swallow electrolyte
Drink a large quantity of water or milk. Get emergency medica l attention immedi-
ately. ■
When there is insuff icient battery fluid
Do not use if there is insufficient fluid in th e battery. There is a possible danger that the
battery may explode.
NOTICE ■
When recharging the battery
Never recharge the battery while the engine is running. Also, be sure all accessories
are turned off. ■
When adding distilled water
Avoid overfilling. Water spilled during ba ttery recharging may cause corrosion.

5857-3. Do-it-yourself maintenance
7
Maintenance and care
RX350_U_OM48E90U Your vehicle is equipped with a tire pressure warning system that uses tire pres-
sure warning valves and transmitters to detect low tire inflation pressure before
serious problems arise.
◆ 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 your Lexus dealer. ( P. 5 8 6 )
◆ Initializing the tire pressure warning system ■
The tire pressure warning system must be initialized in the following circum-
stances: ●
When the tire inflation pressure is changed such as when changing travel-
ing speed. ●
When the tire inflation pressure is changed such as when the tire size is
changed. ●
When rotating the tires
When the tire pressure warning system is initialized, the current tire inflation
pressure is set as the benchmark pressure.Tire pressure warning system ●
The tire pressure detected by the tire
pressure warning system can be dis-
played on the multi-information display. The illustration used is intended as an exam-
ple, and may differ from the image that is
actually displayed on the multi-information
display.●
If the tire pressure drops below a prede-
termined level, the driver is warned by a
screen display and a warning light.
( P. 6 3 6 ) The illustration used is intended as an exam-
ple, and may differ from the image that is
actually displayed on the multi-information
display.

586 7-3. Do-it-yourself maintenance
RX350_U_OM48E90U ■
How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the engine switch off. Initialization cannot be performe d while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire inflation pressure
level. ( P. 6 8 0 )Make sure to adjust the tire pressure to the specified cold tire inflation pressure
level. The tire pressure warning system w ill operate based on this pressure level.
Turn the engine switch to IGNITION ON mode.
Select on the multi-information display. ( P. 9 6 )
Press or of the meter con-
trol switch, select the “TPMS”
screen and then press and hold
the
until the tire pressure
warning light blinks slowly 3
times. “- -” will be displayed for inflation
pressure of each tire on the multi-
information display while the tire
pressure warning system determines
the position of each tire.
When position of each tire is determined, the inflation pressure of each tire will be
displayed on the multi-information display.
Drive the vehicle at approximately 25 mph (40 km/h) or more for approx-
imately 10 to 30 minutes until the inflat ion pressure of each tire is displayed
on the multi-information display. If tire inflation pressure becomes low before the inflation pressure is displayed, the
tire pressure warning light will come on.
Depending on the vehicle and driving conditions, initializati on may take up to
approximately 1 hour to complete.
◆ 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 nec-
essary to register the ID code. Have the ID code registered by your Lexus
dealer. 1
2
3
4
5
6

5877-3. Do-it-yourself maintenance
7
Maintenance and care
RX350_U_OM48E90U ■
When to replace your vehicle’s tires
Tires should be replaced if: ●
The treadwear indicators are showing on a tire. ●
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 prop erly repaired due to the size or location of
a cut or other damage.
If you are not sure, consult with your Lexus dealer. ■
Replacing tires and wheels
If the ID code of the tire pressure warning valve and transmitter is not registered, the tire
pressure warning system will not work proper ly. After driving for about 20 minutes, the
tire pressure warning light blinks for 1 minute and stays on to indicate a system malfunc-
tion. ■
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 pressure checks.
Make sure to check tire inflation pressure as part of your routine of daily vehicle checks.■
Maximum load of tire
Check that the maximum load of the replacem ent tire is greater than 1 /2 of the Gross
Axle Weight Ratings (GAWR) of either the front axle or the rear axle, whichever is
greater.
For the GAWR, see the Certification Label. For
the maximum load of the tire, see the load limit
at maximum cold tire inflation pressure men-
tioned on the sidewall of the tire. ( P. 686)

5897-3. Do-it-yourself maintenance
7
Maintenance and care
RX350_U_OM48E90U ■
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 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.
• 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 wheel without the tire pressure warning valve and transmitter is 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 th at generates strong radio waves or electrical noise.
• When carrying a portable radio, cellular phone, cordless ph one or other wireless
communication device.
If tire position information is not correctl y displayed due to the radio wave conditions,
the display may be corrected by driving and changing the radio wave conditions. ●
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 initialization af ter adjusting the tire inflation pressure.
Also, make sure the tires are cold before carry ing out initialization or tire inflation pres-
sure adjustment. ●
If you have accidentally turned the engine swit ch off during initialization, it is not neces-
sary to press the reset switch again as init ialization will restart automatically when the
engine switch has been turned to IG NITION 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 leve l when the tires are co ld, and conduct initial-
ization again. ●
While the position of each tire is being de termined and the inflation pressures are not
being displayed on the mu lti-information display, if the in flation pressure of a tire drops,
the tire pressure warning light will come on.

590 7-3. Do-it-yourself maintenance
RX350_U_OM48E90U ■
Warning performance of the tire pressure warning system
The warning of the tire pressure warning syst em 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. ■
When initialization of the tire pressure warning system has failed
Initialization may take longer to complete if the vehicle is driven on an unpaved road.
When performing initialization, drive on a pa ved road if possible. Depending on the driv-
ing environment and condition of the tires, initialization will be completed in approxi-
mately 10 to 30 minutes. If initialization is not complete af ter driving approximately 10 to
30 minutes, continue driving for a while.
If the inflation pressure of each tire is not displayed after driving for approximately 1 hour,
perform the following procedure. ●
Park the vehicle in a safe place for approxim ately 20 minutes. Then drive straight (with
occasional left and right turns) at approximately 25 mph (40 km/h) or more for
approximately 10 to 30 minutes.
However, in the following situations, the tire inflation pressure will not be recorded and
the system will not operate properly. Perform initialization again. ●
When operating the tire pressure warning reset switch, the tire pressure warning light
does not blink 3 times. ●
After performing initialization, the tire pres sure warning light blinks for 1 minute then
stays on while driving.
If the inflation pressure of each tire is st ill not displayed, have the vehicle inspected by
your Lexus dealer.

592 7-3. Do-it-yourself maintenance
RX350_U_OM48E90U WA R N I N G ■
When inspecting or replacing tires
Observe the following precautions to prevent accidents.
Failure to do so may cause damage to parts of the drive train as well as dangerous han-
dling characteristics, which may lead to an accident resultin g in death or serious injury.●
Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably 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. ●
Do not tow if your vehicle has a compact spare tire installed. ■
When initializing the tire pressure warning system
Do not initializing tire inflation pressure wi thout first adjusting the tire inflation pressure
to the specified level. Otherwise, the tire pressure warning light may not come on even
if the tire inflation pressure is low, or it may come on when the tire inflation pressure is
actually normal.
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 ar e 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. 585)■
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. ■
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.