2010 Lexus HS250h battery

411
4-2. Maintenance
4
Maintenance and care
General maintenance
Engine compartment
Tr u n k
ItemsCheck points
Brake fluidIs the brake fluid at the correct level?
( P. 4 3 1 )
CoolantIs the engine coolant at the correct
level? ( P. 4 2 8 )
Engine oilIs the engine oil at the correct level? 
( P. 4 2 4 )
Exhaust systemThere should not be any fumes or
strange sounds.
Radiator/condenser
The radiator and condenser should
be free from foreign objects. 
( P. 4 3 0 )
Wa s h e r f l u i dIs there sufficient washer fluid? 
( P. 4 3 2 )
ItemsCheck points
12-volt batteryCheck the connections. ( P. 4 3 3 )
Listed below are the general maintenance items that should be performed
at the intervals specified in the “Warranty and Service Guide” or “Owner’s
Manual Supplement”. It is recommend ed that any problem you notice
should be brought to the attention of your Lexus dealer or qualified service
shop for advice.

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4-2. Maintenance
4
Maintenance and care
Emission inspection and maintenance (I/M) programs
Some states have vehicle emission inspection programs which include
OBD (On Board Diagnostics) checks. The OBD system monitors the oper
-
ation of the emission control system.
■ If the malfunction indicator lamp comes on
The OBD system determines that a pr
oblem exists somewhere in
the emission control system. Your vehicle may not pass the I/M test
and may need to be repaired. Contact your Lexus dealer to service
the vehicle.
■ Y
our vehicle may not pass the I/M test in the following situations:
●When the 12-
volt battery is disconnected or discharged
Readiness codes that are set during ordinary driving are erased. 
Also, depending on your driving habits, the r
eadiness codes may
not be completely set.
● When the fuel tank cap is loose
The malfunction indicator lamp comes on indicating a temporary
malfunction and y

our vehicle may not pass the I/M test.
■ When the malfunction indicator la mp still r
emains on after several
driving trips
The error code in the OBD system will not be clear
ed unless the
vehicle is driven 40 or more times.
■ If y
our vehicle does not pass the I/M test
Contact your Lexus dealer to prep ar
e the vehicle for re-testing.

416
4-3. Do-it-yourself maintenance
Do-it-yourself service precautions
If you perform maintenance by yourself, be sure to follow the correct pro-
cedure as given in these sections.
ItemsPa r t s a n d t o o l s
12-volt battery condition ( P. 4 3 3 )
•Grease
• Conventional wrench 
(for terminal clamp bolts)
Brake fluid level ( P. 4 3 1 )
• FMVSS No.116 DOT 3 or SAE
J1703 brake fluid
•Rag or paper towel
• Funnel (used only for adding brake
fluid)
Engine/power control unit coolant
level ( P. 4 2 8 )
• “Toyota Super Long Life Coolant”
or a similar high quality ethylene
glycol based non-silicate, non-
amine, non-nitrite and non-borate
coolant with long-life hybrid
organic acid technology.
For the U.S.A.: 
“Toyota Super Long Life Coolant”
is pre-mixed with 50% coolant and
50% deionized water.
For Canada: 
“Toyota Super Long Life Coolant”
is pre-mixed with 55% coolant and
45% deionized water.
• Funnel (used only for adding cool- ant)

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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.

434
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.

436
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.

453
4-3. Do-it-yourself maintenance
4
Maintenance and care
Electronic key battery
Replace the battery with a new one if it is depleted.
■You will need the following items:
●F
lathead screwdriver
●Small Phillips-head sc rewd
river
● Lithium batter
y (CR1632)
■ R
eplacing the battery
Take out the mechanical key.
Remove the cover.
To prevent damage to the key,
cover the tip of the screwdriver
with a rag.
Remove the depleted battery.
Insert a new battery with the “+”
terminal facing up.