Lexus HS250h 2010 Hybrid system / LEXUS 2010 HS250H OWNERS MANUAL (OM75006U)

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4-3. Do-it-yourself maintenance
4
Maintenance and care
Brake fluid
■Checking fluid level
The brake fluid level should be
betw
een the “MAX” and “MIN”
lines on the tank.
■ A
dding fluid
Make sure to check the fluid type and prepare the necessary item.
Fluid typeFMVSS No.116 DOT 3 or SAE J1703 brake fluid
ItemsClean funnel
■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.
CAUTION
■When filling the reservoir
Take care as brake fluid can harm your hands and eyes and damage painted sur-
faces. 
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.

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4-3. Do-it-yourself maintenance
Washer fluid
If any washer does not work or the
warning message appears on the
multi-information display, the
washer tank may be empty. Add
washer fluid.
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 refilling, there may be a serious problem.
CAUTION
■When adding washer fluid
Do not add washer fluid when the hybrid system is hot or operating as washer fluid
contains alcohol and may catch fire if spilled on the engine etc.
NOTICE
■Do not use any fluid other than washer fluid
Do not use soapy water or engine antifreeze instead of washer fluid. 
Doing so may cause streaking on the vehicle’s painted surfaces.
■Diluting washer fluid
Dilute washer fluid with water as necessary. 
Refer to the freezing temperatures listed on the washer fluid tank.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
12-volt battery
■Location
The 12-volt battery is located on
the right-hand side of the lug-
gage compartment.
■ Open the co
ver
Lift up the hook and remove the
pa
nel.
Open the cover.

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4-3. Do-it-yourself maintenance
■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 discon -
nect the ground cable.
●Make sure the power switch on the charger is off when connecting and discon -
necting the charger cables to the 12-volt battery.
■After recharging/reconnecting the 12-volt battery
●Unlocking the doors using the smart ke y system may not be possible immedi-
ately after disconnecting 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 “P OWER” switch in ACCESSORY mode. The
hybrid system 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 battery is recon -
nected, the vehicle will return the “POWER” switch mode to the status it was in
be
fore the battery was disconnected. Make sure to turn off the power before
disconnect the battery. Take extra care when connecting the battery if the
“POWER” switch mode prior to discharge is unknown.
If the system will not start even after mult i
ple attempts, contact your Lexus dealer.
■Exterior
Make sure that the 12-volt ba ttery terminals are not corroded and
that there are no loose connect ions, cracks or loose clamps.
Terminals
Hold-down clamp

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4-3. Do-it-yourself maintenance
4
Maintenance and care
CAUTION
■Chemicals in the 12-volt battery
The 12-volt battery contains poisonous and corrosive sulfuric acid and may pro-
duce 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 bat-
tery 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 le ss). The 12-volt 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 medi-
cal 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 atten-
tion immediately.
●If electrolyte gets on your clothes 
It can soak through clothing on to your skin. Immediately take off the clothing and
follow the procedure above if necessary.
●If you accidentally swallow electrolyte 
Drink a large quantity of water or milk. Get emergency medical attention imme-
diately.

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4-3. Do-it-yourself maintenance
CAUTION
■When replacing the 12-volt battery
Use a 12-volt battery designed for this vehicle. Failure to do so may cause gas
(hydrogen) to enter the passenger compartment, causing a fire or explosion.
For replacement of the 12-volt battery, contact your Lexus dealer.
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.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
Tires
Replace or rotate tires in accordance with maintenance schedules and
treadwear.
■Checking tires
New tread
Treadwear indicator
Worn tread
The location of treadwear indi-
cators is shown by the “TWI” or
“ ”

marks, etc., molded on the
sidewall of each tire.
Check spare tire condition and
pr
essure if not rotated.
■ Tire rotation
Rotate the tires in the order
sho
wn.
To equalize tire wear and extend
tire life, Lexus recommends that
tire rotation is carried out at the
same interval as tire inspection.
P225/45R18 91W tires: 
Do not fail to initialize the tire
pr
essure warning system after
tire rotation.
■ Tire pressure warning system
Your vehicle is equipped with a ti r
e pressure warning system that
uses tire pressure warning valves and transmitters to detect low tire
inflation pressure before serious problems arise. ( P. 4 9 5 , 504 ,
505)
Front

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4-3. Do-it-yourself maintenance
Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and trans-
mitters must also be installed.
When new tire pressure warning va lv
es 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 pres-
sure warning valve and transmitter ID codes r
egistered by your Lexus
dealer. ( P. 4 3 9 )
Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following
circumstances:
● V
ehicles with P225/45R18 91W tires: When rotating front and rear
tires which have different tire inflation pressures
● When changing the tir
e size
When the tire pressure warning sys tem is initializ
ed, the current tire
inflation pressure is set as the benchmark pressure.

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4-3. Do-it-yourself maintenance
4
Maintenance and care
■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. 555 )
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.
Press and hold the tire pressure warning reset switch until the tire
pressure warning light flashes slo
wly 3 times and the message
“TIRE PRESSURE RESET PROC EEDING” appears on the
multi-information display.
Wait for a few minutes with th e “P
OWER” switch in ON mode
and then turn the “POWER” 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. Ha ve the ID code registered by your
Lexus dealer.

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4-3. Do-it-yourself maintenance
■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 your Lexus dealer.
■Replacing tires and wheels
If the ID code of the tire pressure warning valve and transmitter is not registered,
the tir
e pressure warning system will not work properly. After driving for about 20
minutes, the tire pressure warning light flas hes 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 sel-
dom 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
ch
ecks. Make sure to check tire inflation pressure as part of your routine of daily
vehicle checks.
■Low profile tires (vehicles with P225/45R18 91W tires)
Generally, low profile tires will wear more rapidly and tire grip performance will be
r
educed on snowy and/or icy roads when co mpared 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.