fuel SUBARU IMPREZA WRX 2012 4.G Service Manual

Maintenance schedule
The scheduled maintenance items re-
quired to be serviced at regular intervals
are shown in the“Warranty and Main-
tenance Booklet ”.
For details of your maintenance schedule,
read the separate “Warranty and Main-
tenance Booklet ”. Maintenance precautions
When maintenance and service are re-
quired, it is recommended that all work be
done by an authorized SUBARU dealer.
If you perform maintenance and service
by yourself, you should familiarize yourself
with the information provided in this
section on general maintenance and
service for your SUBARU.
Incorrect or incomplete service could
cause improper or unsafe vehicle opera-
tion. Any problems caused by improper
maintenance and service performed by
you are not eligible for warranty coverage.
WARNING
. Testing of an All-Wheel Drive
model must NEVER be per-
formed on a single two-wheel
dynamometer or similar appara-
tus. Attempting to do so will
result in transmission damage
and in uncontrolled vehicle
movement and may cause an
accident or injuries to persons
nearby.
. Always select a safe area when
performing maintenance on yourvehicle. .
Always be very careful to avoid
injury when working on the vehi-
cle. Remember that some of the
materials in the vehicle may be
hazardous if improperly used or
handled, for example, batteryacid.
. Your vehicle should only be ser-
viced by persons fully competent
to do so. Serious personal injury
may result to persons not experi-
enced in servicing vehicles.
. Always use the proper tools and
make certain that they are wellmaintained.
. Never get under the vehicle sup-
ported only by a jack. Always use
safety stands to support thevehicle.
. Never keep the engine running in
a poorly ventilated area, such as
a garage or other closed areas.
. Do not smoke or allow open
flames around the fuel or battery.
This will cause a fire.
. Because the fuel system is under
pressure, replacement of the fuel
filter should be performed only
by your SUBARU dealer.
. Wear adequate eye protection to Maintenance and service
11-3
– CONTINUED –

11-8Maintenance and service
Engine oil NOTE .The engine oil consumption rate is
not stabilized, and therefore cannot be
determined until the vehicle has tra-
veled at least several thousand miles
(kilometers). Even after break-in, when
the vehicle is used under severe driv-
ing conditions such as those men-
tionedintheWarrantyandMainte-
nance Booklet, engine oil is consumed
or deteriorated more quickly than un-
der normal driving conditions. If you
drive your vehicle under these severe
conditions, you should check the oil
level at least at every second fuel fill-up
time, and change the oil more fre-
quently. Please refer to the Warranty
and Maintenance Booklet for more de-tails.. If the oil consumption rate seems
abnormally high after the break-in
period, for example more than 1 quart
per 1,200 miles or 1 liter per 2,000
kilometers, contact your SUBARU deal-
er. &
Checking the oil level
Check the engine oil level at each fuelstop.
1. Park the vehicle on a level surface and
stop the engine.
2. Pull out the level gauge that has the “” symbol on top, wipe it clean, and
insert it again.
3. Be sure the level gauge is correctly
inserted until it stops.
1) Notch
2) Upper level
3) Lower level
4. Pull out the level gauge again and
check the oil level on it. If it is below the
lower level, add oil to bring the level up to
the upper level.
CAUTION
. Use only engine oil with the
recommended grade and vis-
cosity.
. Be careful not to spill engine oil
when adding it. If oil touches the
exhaust pipe, it may cause a bad
smell, smoke, and/or a fire. If
engine oil gets on the exhaust

11-10Maintenance and service
thin coat of engine oil to the seal.
9. Clean the rubber seal seating area of
the bottom of engine and install the oil
filter by hand turning. Be careful not to
twist or damage the seal.
10. Tighten the oil filter by the amount
indicated in the following table after the
seal makes contact with the bottom ofengine.
Oil filter color Part number Amount of
rotation
Black 15208AA100 1 rotation
Blue 15208AA12A 7/8
rotation
CAUTION
. Never over tighten the oil filter
because that can result in an oil leak.
. Thoroughly wipe off any engine
oil that has spilled over the
exhaust pipe and/or under-cover.
If spilled oil is not promptly
wiped up, the oil could cause afire.
11. Reinstall under cover.
12. Pour engine oil through the filler neck.
For the oil capacity (guideline), refer to “
Engine oil ”F 12-5.
The oil quantity indicated above is onlyguideline.
The necessary quantity of oil depends on
the quantity of oil that has been drained.
The quantity of drained oil differs slightly
depending on the temperature of the oil
and the time the oil is left flowing out. After
refilling the engine with oil, therefore, you
must use the level gauge to confirm that
the level is correct.
13. Start the engine and make sure that no
oil leaks appear around the filter ’s rubber
seal and drain plug.
14. Run the engine until it reaches the
normal operating temperature. Then stop
the engine and wait a few minutes to allow
the oil drain back. Check the oil level
again and if necessary, add more engineoil.
CAUTION
Be careful not to spill engine oil
when adding it. If oil touches the
exhaust pipe, it may cause a bad
smell, smoke, and/or a fire. &
Recommended grade and viscosity
CAUTION
Use only engine oil with the recom-
mended grade and viscosity.
Refer to “Engine oil ”F 12-5.
NOTE
Engine oil viscosity (thickness) affects
fuel economy. Oils of lower viscosity
provide better fuel economy. However,
in hot weather, oil of higher viscosity is
required to properly lubricate the en-gine. & Synthetic oil
You should use synthetic engine oil that
meets the same requirements given for
conventional engine oil. When using
synthetic oil, you must use oil of the same
classification, viscosity and grade shown
in this Owner ’s Manual. Refer to “Engine
oil ”F 12-5. Also, you must follow the oil
and filter changing intervals shown in the
Warranty and Maintenance booklet.
NOTE
Synthetic oil of the grade and viscosity
noted in chapter 12 is the recom-

11-12Maintenance and service
&Engine coolant
! Checking the coolant level
WARNING
Never attempt to remove the radia-
tor cap until the engine has been
shut off and has cooled down
completely. Since the coolant is
under pressure, you may suffer
serious burns from a spray of boil-
ing hot coolant when the cap isremoved.
1) “FULL ”level mark
2) “LOW ”level mark
Check the coolant level at each fuel stop.
1. Check the coolant level on the outside of the reservoir while the engine is cool.
2. If the level is close to or lower than the “
LOW ”level mark, add coolant up to the
“ FULL ”level mark. If the reserve tank is
empty, remove the radiator cap and refill
as required.
3. After refilling the reserve tank and the
radiator, reinstall the cap and check that
the rubber gaskets inside the radiator cap
are in the proper position.
WARNING
Never attempt to remove the radia-
tor cap until the engine has been
shut off and has cooled down
completely. Since the coolant is
under pressure, you may suffer
serious burns from a spray of boil- ing hot coolant when the cap isremoved.
CAUTION
. Be careful not to spill engine
coolant when adding it. If coolant
touches the exhaust pipe, it may
cause a bad smell, smoke, and/or
a fire. If engine coolant gets on
the exhaust pipe, be sure to wipe
it off.
. Do not splash the engine coolant
over painted parts. The alcohol
contained in the engine coolant
may damage the paint surface.
! Changing the coolant
It may be difficult to change the coolant.
Have the coolant changed by your
SUBARU dealer if necessary.
The coolant should be changed according
to the maintenance schedule in the“ Warranty and Maintenance Booklet ”.

one minute.
When a tire is replaced, adjustments are
necessary to ensure continued normal
operation of the tire pressure monitoring
system. As with wheel replacement, there-
fore, you should have the work performed
by a SUBARU dealer.
WARNING
If the low tire pressure warning light
does not illuminate briefly after the
ignition switch is turned ON or the
light illuminates steadily after blink-
ing for approximately one minute,
you should have your Tire Pressure
Monitoring System checked at a
SUBARU dealer as soon as possi-ble.
If this light illuminates while driving,
never brake suddenly and keep
driving straight ahead while gradu-
ally reducing speed. Then slowly
pull off the road to a safe place.
Otherwise an accident involving
serious vehicle damage and serious
personal injury could occur.
If this light still illuminates while
driving after adjusting the tire pres-
sure, a tire may have significant
damage and a fast leak that causes
the tire to lose air rapidly. If you have a flat tire, replace it with a spare tire
as soon as possible.
When a spare tire is mounted or a
wheel rim is replaced without the
original pressure sensor/transmitter
being transferred, the low tire pres-
sure warning light will illuminate
steadily after blinking for approxi-
mately one minute. This indicates
the TPMS is unable to monitor all
four road wheels. Contact your
SUBARU dealer as soon as possible
for tire and sensor replacement and/
or system resetting. If the light
illuminates steadily after blinking
for approximately one minute,
promptly contact a SUBARU dealer
to have the system inspected.
& Tire inspection
Check on a daily basis that the tires are
free from serious damage, nails, and
stones. At the same time, check the tires
for abnormal wear.
Contact your SUBARU dealer immedi-
ately if you find any problem. NOTE . When the wheels and tires strike
curbs or are subjected to harsh treat-
ment as when the vehicle is driven on a rough surface, they can suffer damage
that cannot be seen with the naked eye.
This type of damage does not become
evident until time has passed. Try not
to drive over curbs, potholes or on
other rough surfaces. If doing so is
unavoidable, keep the vehicle
’s speed
down to a walking pace or less, and
approach the curbs as squarely as
possible. Also, make sure the tires are
not pressed against the curb when you
park the vehicle.. If you feel unusual vibration while
driving or find it difficult to steer the
vehicle in a straight line, one of the
tires and/or wheels may be damaged.
Drive slowly to the nearest authorized
SUBARU dealer and have the vehicleinspected.
& Tire pressures and wear
Maintaining the correct tire pressures
helps to maximize the tires ’service lives
and is essential for good running perfor-
mance. Check and, if necessary, adjust
the pressure of each tire (including the
spare) at least once a month (for example,
during a fuel stop) and before any long
journey. Maintenance and service
11-25
– CONTINUED –

11-26Maintenance and service
Check the tire pressures when the tires
are cold. Use a pressure gauge to adjust
the tire pressures to the values shown on
the tire placard. The tire placard is located
on the door pillar on the driver ’s side.
Driving even a short distance warms up
the tires and increases the tire pressures.
Also, the tire pressures are affected by the
outside temperature. It is best to check tire
pressure outdoors before driving thevehicle.
When a tire becomes warm, the air inside
it expands, causing the tire pressure to
increase. Be careful not to mistakenly
release air from a warm tire to reduce itspressure. NOTE .
The air pressure in a tire increases
by approximately 4.3 psi (30 kPa, 0.3 kgf/cm
2) when the tire becomes warm.
. The tires are considered cold when
the vehicle has been parked for at least
three hours or has been driven less
than one mile (1.6 km).
WARNING
Do not let air out of warm tires to
adjust pressure. Doing so will result
in low tire pressure.
Incorrect tire pressures detract from con-
trollability and ride comfort, and they
cause the tires to wear abnormally. .
Correct tire pressure (tread worn
evenly)
Roadholding is good, and steering is
responsive. Rolling resistance is low, so
fuel consumption is also lower.

.Abnormally low tire pressure (tread
worn at shoulders)
Rolling resistance is high, so fuel con-
sumption is also higher. .
Abnormally high tire pressure (tread
worn in center)Ride comfort is poor. Also, the tire
magnifies the effects of road-surface
bumps and dips, possibly resulting in
vehicle damage.
If the tire placard shows tire pressures for
the vehicle when fully loaded, adjust the
tire pressures to the values that match
current loading conditions.
WARNING
Driving at high speeds with exces-
sively low tire pressures can cause
the tires to deform severely and to
rapidly become hot. A sharp in-
crease in temperature could cause
tread separation, and destruction of the tires. The resulting loss of
vehicle control could lead to anaccident.
& Wheel balance
Each wheel was correctly balanced when
your vehicle was new, but the wheels will
become unbalanced as the tires become
worn during use. Wheel imbalance causes
the steering wheel to vibrate slightly at
certain vehicle speeds and detracts from
the vehicle ’s straight-line stability. It can
also cause steering and suspension sys-
tem problems and abnormal tire wear. If
you suspect that the wheels are not
correctly balanced, have them checked
and adjusted by your SUBARU dealer.
Also have them adjusted after tire repairs
and after tire rotation.
CAUTION
Loss of correct wheel alignment
causes the tires to wear on one side
and reduces the vehicle ’s running
stability. Contact your SUBARU
dealer if you notice abnormal tire
wear. Maintenance and service
11-27
– CONTINUED –

Specifications..................................................... 12-2
Dimensions ........................................................ 12-2
Engine ............................................................... 12-3
Electrical system ................................................ 12-3
Fuel ................................................................... 12-4
Lubricants. ......................................................... 12-5
Fluids ................................................................ 12-7
Engine coolant ................................................... 12-8 Tires
.................................................................. 12-9
Fuses and circuits ........................................... 12-10
Fuse panel located in the passenger compartment ................................................. 12-10
Fuse panel located in the engine compartment ................................................. 12-12
Bulb chart ......................................................... 12-14
Vehicle identification ....................................... 12-17Specifications
12

12-4Specifications
&Fuel
NOTE
The engine is designed to operate using unleaded gasoline.
Model Fuel requirement Fuel tank capacity
Except STI 91 AKI (95 RON) or higher*
1
16.9 US gal (64 liters, 14.1 Imp gal)
STI 93 AKI (98 RON) or higher*2
*1: If unleaded gasoline with an octane rating of 91 AKI (95 RON) is not available, unleaded gasoline with an octane rating of 87 AKI (90 RON) or higher
may be temporarily used. For details, refer to
“Fuel ”F 7-3.
*2: If unleaded gasoline with an octane rating of 93 AKI (98 RON) is not available, unleaded gasoline with an octane rating of 91 AKI (95 RON) may be
used with no detriment to engine durability or driveability. For details, refer to “Fuel ”F 7-3.

12-12Specifications
&Fuse panel located in the engine compartment
A) Main fuse Fuse
panel Fuse
rating Circuit
1 30A .ABS unit
. Vehicle Dynamics Con-
trol unit
2 25A .Main fan (cooling fan)
3 10A .Secondary air combina-
tion valve (turbo models)
4 25A .Sub fan (cooling fan)
5 Empty
6 10A .Audio
7 30A .Headlight (low beam)
8 15A .Headlight (high beam)
9 20A .Back-up
10 15A .Horn
11 25A .Rear window defogger
. Mirror heater
12 15A .Fuel pump
13 10A .Automatic transmission
control unit
14 7.5A .Engine control unit
15 15A .Turn and hazard warn-
ing flasher
16 15A .Tail and illumination re-
lay
17 7.5A .Alternator