LEXUS RX 450H (2019 year). Manual - part 38

608

7-3. Do-it-yourself maintenance

RX450h_RX450hL_U



RX450h

Install the 12-volt battery cover with the
clips.

Push up center position
Insert
Press



RX450hL
Install the deck side trim cover.

Install the 12-volt battery cover.

Installing the 12-volt battery cover

1

2
3

1

2

609

7-3. Do-it-yourself maintenance

7

Main

tenance an

d care

RX450h_RX450hL_U

■

Before recharging
When recharging, the 12-volt battery produces hydrogen gas which is flammable and

explosive. Therefore, observe the following precautions before recharging:

●

If recharging with the 12-volt battery installed on the vehicle, be sure to disconnect the

ground cable.

●

Make sure the power switch on the charger is off when connecting and disconnecting

the charger cables to the 12-volt battery.

■

After recharging/reconnecting the 12-volt battery

●

The hybrid system may not start. Follow the procedure below to initialize the system.

Shift the shift lever to P.
Open and close any of the doors.
Restart the hybrid system.

●

Unlocking the doors using the smart access system with push-button start may not be

possible immediately after reconnecting the 12-volt battery. If this happens, use the

wireless remote control or the mechanical key to lock/unlock the doors.

●

Start the hybrid system with the power switch in ACCESSORY mode. The hybrid sys-

tem may not start with the power switch turned off. However, the hybrid system will

operate normally from the second attempt.

●

The power switch mode is recorded by the vehicle. If the 12-volt battery is reconnected,

the vehicle will return the power switch mode to the status it was in before the 12-volt

battery was disconnected. Make sure to turn off the power before disconnect the 12-

volt battery. Take extra care when connecting the 12-volt battery if the power switch

mode prior to discharge is unknown.

If the system will not start even after multiple attempts at all methods above, contact your

Lexus dealer.

WARNING

■

Chemicals in the 12-volt battery
The 12-volt battery contains poisonous and corrosive sulfuric acid and may produce

hydrogen gas which is flammable and explosive. To reduce the risk of death or serious

injury, take the following precautions while working on or near the 12-volt battery:

●

Do not cause sparks by touching the 12-volt battery terminals with tools.

●

Do not smoke or light a match near the 12-volt battery.

●

Avoid contact with eyes, skin and clothes.

●

Never inhale or swallow electrolyte.

●

Wear protective safety glasses when working near the 12-volt battery.

●

Keep children away from the 12-volt battery.

■

Where to safely charge the 12-volt battery
Always charge the 12-volt battery in an open area. Do not charge the 12-volt battery in

a garage or closed room where there is insufficient ventilation.

■

How to recharge the 12-volt battery
Only perform a slow charge (5 A or less). The 12-volt battery may explode if charged

at a quicker rate.

1

2
3

610

7-3. Do-it-yourself maintenance

RX450h_RX450hL_U

WARNING

■

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 feel 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 medical attention immedi-

ately.

■

When handling the 12-volt battery
P. 700

■

When disconnecting the 12-volt battery (RX450h)

NOTICE

■

When recharging the 12-volt battery
Never recharge the 12-volt battery while the hybrid system is operating. Also, be sure

all accessories are turned off.

Do not disconnect the negative (-) terminal on

the body side as shown. The disconnected neg-

ative (-) terminal may touch the positive (+) ter-

minal, which may cause a short and result in

death or serious injury.

611

7-3. Do-it-yourself maintenance

7

Main

tenance an

d care

RX450h_RX450hL_U

Check if the treadwear indicators are showing on the tires. Also check the tires
for uneven wear, such as excessive wear on one side of the tread.
Check the spare tire condition and pressure if not rotated.

New tread
Worn tread
Treadwear indicator

The location of treadwear indicators is shown by a “TWI” or “

” mark, etc., molded

into the sidewall of each tire.
Replace the tires if the treadwear indicators are showing on a tire.

Rotate the tires in the order shown.

To equalize tire wear and extend tire life,

Lexus recommends that tire rotation is

carried out at the same interval as tire

inspection.
Do not fail to initialize the tire pressure

warning system after tire rotation.

Tires

Replace or rotate tires in accordance with maintenance schedules and tread-
wear.

Checking tires

Tire rotation

1

2
3

Front

612

7-3. Do-it-yourself maintenance

RX450h_RX450hL_U

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. 613)

◆

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. 662)

The illustration used is intended as an exam-

ple, and may differ from the image that is

actually displayed on the multi-information

display.

613

7-3. Do-it-yourself maintenance

7

Main

tenance an

d care

RX450h_RX450hL_U

■

How to initialize the tire pressure warning system

Park the vehicle in a safe place and turn the power switch off.

Initialization cannot be performed while the vehicle is moving.

Adjust the tire inflation pressure to the specified cold tire inflation pressure
level. (

P. 717)

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 power switch to ON mode.

Select 

 on the multi-information display. (

P. 108)

Press 

 or 

 of the meter control switch, select the “Vehicle Settings”

screen and then press the 

.

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 inflation 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, initialization 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

7

614

7-3. Do-it-yourself maintenance

RX450h_RX450hL_U

■

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 properly 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 properly. 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.

■

Proper storage of the spare tire (RX450hL)
As an improperly stored spare tire may cause damage to the wire cable that holds it,

check that the spare tire is stored properly on a daily basis.

If the spare tire is slanted, the hoist assembly may be stuck in the wheel opening. If the

spare tire rattles while driving, it may not be fully raised. Lower the spare tire to the

ground and make sure that the hoist assembly is perpendicular to the wheel opening.
Raise the tire slowly and steadily until a click is heard and the jack handle skips.

If the spare tire cannot be lowered, the wire cable may be severed. Have the vehicle

inspected at your Lexus dealer.

■

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.

●

If the stored spare tire appears to be slanted or

rattles while driving, the spare tire may not be

properly stored. Store the spare tire again by

performing the following tire change proce-

dure correctly:

1

2

615

7-3. Do-it-yourself maintenance

7

Main

tenance an

d care

RX450h_RX450hL_U

■

Maximum load of tire
Check that the maximum load of the replacement 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.

■

Tire types

●

Summer tires
Summer tires are high-speed performance tires best suited to highway driving under

dry conditions. Since summer tires do not have the same traction performance as

snow tires, summer tires are inadequate for driving on snow-covered or icy roads. For

driving on snow-covered roads or icy roads, the use of snow tires is recommended.

When installing snow tires, be sure to replace all four tires.

●

All season tires
All season tires are designed to provide better traction in snow and to be adequate for

driving in most winter conditions as well as for use year-round. All season tires, how-

ever, do not have adequate traction performance compared with snow tires in heavy

or loose snow. Also, all season tires fall short in acceleration and handling perfor-

mance compared with summer tires in highway driving.

●

Snow tires
For driving on snow-covered roads or icy roads, we recommend using snow tires. If

you need snow tires, select tires of the same size, construction and load capacity as the

originally installed tires. Since your vehicle has radial tires as original equipment, make

sure your snow tires also have radial construction. Do not install studded tires without

first checking local regulations for possible restrictions. Snow tires should be installed

on all wheels. (

P. 390)

■

Initializing the tire pressure warning system
Initialize the system with the tire inflation pressure adjusted to the specified level.

■

If the tread on snow tires wears down below 0.16 in. (4 mm)
The effectiveness of the tires as snow tires is lost.

■

If you press the tire pressure warning reset switch accidentally
If initialization is performed, adjust the tire inflation pressure to the specified level and ini-

tialize the tire pressure warning system again. 

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. 723)

616

7-3. Do-it-yourself maintenance

RX450h_RX450hL_U

■

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 that generates strong radio waves or electrical noise.

• When carrying a portable radio, cellular phone, cordless phone or other wireless

communication device.

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 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 after adjusting the tire inflation pressure.

Also, make sure the tires are cold before carrying 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 the specified level when the tires are cold, and conduct initial-

ization again.

●

While the position of each tire is being determined and the inflation pressures are not

being displayed on the multi-information display, if the inflation pressure of a tire drops,

the tire pressure warning light will come on.

617

7-3. Do-it-yourself maintenance

7

Main

tenance an

d care

RX450h_RX450hL_U

■

Warning performance of the tire pressure warning system
The warning of the tire pressure 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.

■

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 paved 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 after 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 approximately 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 pressure warning light blinks for 1 minute then

stays on while driving.

If the inflation pressure of each tire is still not displayed, have the vehicle inspected by

your Lexus dealer.

618

7-3. Do-it-yourself maintenance

RX450h_RX450hL_U

■

Certification for tire pressure warning system



Except for vehicles sold in Canada



For vehicles sold in Canada

619

7-3. Do-it-yourself maintenance

7

Main

tenance an

d care

RX450h_RX450hL_U

WARNING

■

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 resulting 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 without 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 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 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 liquid sealant 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. 612)

■

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 each tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

620

7-3. Do-it-yourself maintenance

RX450h_RX450hL_U

The recommended cold tire inflation
pressure and tire size are displayed on
the tire and loading information label.
(

P. 717)

Tire inflation pressure

Tire inflation pressure

621

7-3. Do-it-yourself maintenance

7

Main

tenance an

d care

RX450h_RX450hL_U

Tire valve
Tire pressure gauge

Remove the tire valve cap.
Press the tip of the tire pressure gauge onto the tire valve.
Read the pressure using the gauge gradations.
If the tire inflation pressure is not at the recommended level, adjust the pres-
sure.
If you add too much air, press the center of the valve to deflate.
After completing the tire inflation pressure measurement and adjustment,
apply soapy water to the valve and check for leakage.
Put the tire valve cap back on.

■

Tire inflation pressure check interval
You should check tire inflation pressure every two weeks, or at least once a month.

Do not forget to check the spare.

■

Effects of incorrect tire inflation pressure
Driving with incorrect tire inflation pressure may result in the following:

●

Reduced fuel economy

●

Reduced driving comfort and poor handling

●

Reduced tire life due to wear

●

Reduced safety

●

Damage to the drive train

If a tire needs frequent inflating, have it checked by your Lexus dealer.

Inspection and adjustment procedure

1

2

1

2
3
4

5

6

622

7-3. Do-it-yourself maintenance

RX450h_RX450hL_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 resulting 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 on the road, etc.)

NOTICE

■

When inspecting and adjusting 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.

623

7-3. Do-it-yourself maintenance

7

Main

tenance an

d care

RX450h_RX450hL_U

When replacing wheels, care should be taken to ensure that they are equivalent
to those removed in load capacity, diameter, rim width and inset

*

.

Replacement wheels are available at your Lexus dealer.

*

: Conventionally referred to as “offset”.

Lexus does not recommend using the following:

●

Wheels of different sizes or types

●

Used wheels

●

Bent wheels that have been straightened

●

Use only Lexus wheel nuts and wrenches designed for use with your alumi-
num wheels.

●

When rotating, repairing or changing your tires, check that the wheel nuts are
still tight after driving 1000 miles (1600 km).

●

Be careful not to damage the aluminum wheels when using tire chains.

●

Use only Lexus genuine balance weights or equivalent and a plastic or rubber
hammer when balancing your wheels.

■

When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and transmit-

ters that allow the tire pressure warning system to provide advance warning in the event

of a loss in tire inflation pressure. Whenever wheels are replaced, tire pressure warning

valves and transmitters must be installed. (

P. 612)

Wheels

If a wheel is bent, cracked or heavily corroded, it should be replaced. Other-
wise, the tire may separate from the wheel or cause a loss of handling control.

Wheel selection

Aluminum wheel precautions