2010 TOYOTA PRIUS maintenance

438 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.
■After recharging/reconnecting the 12 volt battery
● Unlocking the doors using the smart key system may not be possible
immediately 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 “POWER” 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
reconnected, the vehicle will return the “POWER” switch mode to the sta-
tus it was in before the battery was disconnected. Make sure to turn off
the power before disconnect the battery. Take extra care when connect-
ing the battery if the “POWER” switch mode prior to discharge is
unknown.
If the system will not start even after multiple attempts, contact your Toyota
dealer.
CAUTION
■ 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.

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Maintenance and care
PRIUS_U (OM47668U) U.S.A.
CAUTION
■
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 not sufficient ventilation.
■ How to recharge the 12 volt battery
Only perform a slow charge (4.2 A or less). 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 immedi-
ate 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 a burning sensation,
seek medical attention immediately.
● If electrolyte gets on your clothes
It can soak through clothing on to your skin. Immediately take off the cloth-
ing and follow the procedure above if necessary.
● If you accidentally swallow electrolyte 
Drink a large quantity of water or milk. Get emergency medical attention
immediately.

440 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.
CAUTION
■When disconnecting the 12 volt battery
NOTICE
■When recharging th e 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 (-) termi-
nal on the body side as shown. The dis-
connected negative (-) terminal may
touch the positive (+) terminal, which may
cause a short and result in death or seri-
ous injury.

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Maintenance and care
PRIUS_U (OM47668U) U.S.A.
Tires
Replace or rotate tires in accordance with maintenance sched-
ules and treadwear.
■Checking tires
New tread
Treadwear indicator
Worn tread
The location of treadwear
indicators is shown by the
“TWI” or “” marks, etc.,
molded on the sidewall of
each tire.
Check spare tire condition
and inflation pressure if not
rotated.
■ Tire rotation
Rotate the tires in the order
shown.
To equalize tire wear and
extend tire life, Toyota recom-
mends that tire rotation is
carried out at the same inter-
val as tire inspection.
Do not fail to initialize the tire
pressure warning system
after tire rotation.
ITO43P115
Front

442 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.
Installing tire pressure warning valves and transmittersWhen replacing tires or wheels, ti re pressure warning valves and
transmitters must also be installed.
When new tire pressure warning valves and transmitters are
installed, new tire pressure warn ing valve and transmitter ID codes
must be registered in the tire pres sure warning computer and tire
pressure warning system must be initialized. Have tire pressure
warning valve and transmitter ID codes registered by Toyota dealer. 
(  P. 444)
Initializing the tire pressure warning system
■ The tire pressure warning system must be initialized in the fol-
lowing circumstances
●When rotating the tires on vehicles differing with front and rear
tire inflation pressures.
● When changing the tire inflation pressure by changing traveling
speed or load weight, etc.
● When changing the tire size.
When the tire pressure warning system is initialized, the current
tire inflation pressure is set as the pressure benchmark.
■ The tire pressure warning system
Your Toyota is equipped with a tire pressure warning system that
uses tire pressure warning valves and transmitters to detect low
tire inflation pressure before serious problems arise. (P. 499)
The compact spare tire is not equipped with a tire pressure
warning valve and transmitter.

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Maintenance and care
PRIUS_U (OM47668U) U.S.A.
■
How to initialize the tire pressure warning system
Park the vehicle in safe plac e and turn the “POWER” switch
OFF.
While the vehicle is moving, in itialization is not performed.
Adjust the tire inflation pressure to the specified cold tire infla-
tion pressure level. ( P. 565)
Make sure to adjust the tire pressure to the specified cold tire
inflation pressure level. The ti re pressure warning system will
operate based on this pressure level.
Turn the “POWER” switch to ON mode.
Push and hold the tire pressure
warning reset switch until the tire
pressure warning light blinks
slowly 3 times.
Wait for a few minutes with the ON mode, and then turn
“POWER” switch OFF.
STEP1
STEP2
STEP3
STEP4
STEP5

444 4-3. Do-it-yourself maintenance
PRIUS_U (OM47668U) U.S.A.
Registering ID codesThe tire pressure warning valve and transmitter is equipped with a
unique ID code. When replacing a ti re pressure warning valve and
transmitter, it is necessary to regist er the ID code of tire pressure
warning valve and transmitter. Have the ID code registered by your
Toyota dealer.
■ 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 or 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 Toyota dealer.
■ Replacing tires and wheels
If the ID code of the tire pressure warning valve and transmitter is not regis-
tered, the tire pressure warning system will not work properly. After driving
for about 20 minutes, the tire pressure warning light comes on after blinking
for 1 minute to indicate a system malfunction.

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Maintenance and care
PRIUS_U (OM47668U) U.S.A.
■
Tire life
Any tire over 6 years old must be checked by a qualified technician even if
they have seldom or never been used or damage is not obvious.
■ If the tread wears down below 0.16 in. (4 mm) on snow tires
The effectiveness of snow tires is lost.
■ Low profile tires (vehic les with 17-inch tires)
Generally, low profile tires will wear more rapidly and tire grip performance
will be reduced on snowy and/or icy roads when compared 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.
■
Maximum load of tire
Check that the maximum load of the re placement 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 mentioned on the
sidewall of the tire.( P. 572)