engine SUBARU IMPREZA WRX 2012 4.G Service Manual

Fuel
CAUTION
Use of a fuel which is low in quality
or use of an inappropriate fuel
additive may cause engine damage.
& Fuel requirements
! Except STI
The engine is designed to operate usingpremium unleaded gasoline with an
octane rating of 91 AKI (95 RON) or
higher . If premium unleaded gasoline is
not available, regular unleaded gasoline
with an octane rating of 87 AKI (90 RON)
or higher may be temporarily used. For
optimum engine performance and drive-
ability, it is required that you use premium
grade unleaded gasoline. NOTE
Be sure to use premium unleaded
gasoline of 91 AKI (95 RON) or higher.
If other gasoline (lower than 91 AKI (95
RON)) is used, knocking, reduced out-
put and poor accelerator response willresult. !
STI
The engine is designed to operate at
maximum performance using unleaded
gasoline with an octane rating of 93 AKI
(98 RON) or higher . If 93 AKI (98 RON)
fuel is not readily available in your area,
unleaded gasoline with an octane rating of
91 AKI (95 RON) may be used with no
detriment to engine durability or driveabil-
ity. However, you may notice a slight
decrease in maximum engine perfor-
mance while using 91 AKI (95 RON) fuel.
Use of 91 AKI (95 RON) fuel will not affect
your warranty coverage. ! Fuel octane rating
This octane rating is the average of the
Research Octane and Motor Octane
numbers and is commonly referred to as
the Anti Knock Index (AKI).
Using a gasoline with a lower octane
rating can cause persistent and heavy
knocking, which can damage the engine.
Do not be concerned if your vehicle
sometimes knocks lightly when you drive
up a hill or when you accelerate. Contact
your SUBARU dealer if you use a fuel with
the specified octane rating and your
vehicle knocks heavily or persistently. ! Unleaded gasoline
The neck of the fuel filler pipe is designed
to accept only an unleaded gasoline filler nozzle. Under no circumstances should
leaded gasoline be used because it will
damage the emission control system and
may impair driveability and fuel economy. !
Gasoline for California-certified LEV
If your vehicle was certified to California ’s
low emission vehicle (LEV) standards as
indicated on the underhood tune-up label,
it is designed to optimize engine and
emission performance with gasoline that
meets the clean burning low-sulfur Cali-
fornia gasoline specifications. If you live in
any other state than California, your
vehicle will operate on gasoline meeting
Federal specifications. Gasoline sold out-
side California is permitted to have higher
sulfur levels, which may affect the perfor-
mance of your vehicle ’s catalytic converter
and may produce a sulfur exhaust odor or
smell. SUBARU recommends that you try
a different brand of unleaded gasoline
having lower sulfur to determine if the
problem is fuel related before returning
your vehicle to an authorized dealer forservice. ! MMT
Some gasoline contains an octane-en-
hancing additive called MMT (Methylcy-
clopentadienyl Manganese Tricarbonyl). If
you use such fuels, your emission control Starting and operating
7-3
– CONTINUED –

7-4Starting and operating
system performance may deteriorate and
the CHECK ENGINE warning light/Mal-
function indicator light may turn on. If this
happens, return to your authorized
SUBARU Dealer for service. If it is
determined that the condition is caused
by the type of fuel used, repairs may not
be covered by your warranty. !Gasoline for cleaner air
Your use of gasoline with detergent
additives will help prevent deposits from
forming in your engine and fuel system.
This helps keep your engine in tune and
your emission control system working
properly, and is a way of doing your part
for cleaner air. If you continuously use a
high quality fuel with the proper detergent
and other additives, you should never
need to add any fuel system cleaning
agents to your fuel tank.
Many gasolines are now blended with
materials called oxygenates. Use of these
fuels can also help keep the air cleaner.
Oxygenated blend fuels, such as MTBE
(Methyl Tertiary Butyl ether) or ethanol
(ethyl or grain alcohol) may be used in
your vehicle, but should contain no more
than 15% MTBE or 10% ethanol for the
proper operation of your SUBARU.
In addition, some gasoline suppliers are
now producing reformulated gasolines, which are designed to reduce vehicle
emissions. SUBARU approves the use of
reformulated gasoline.
If you are not sure what the fuel contains,
you should ask your service station
operators if their gasolines contain deter-
gents and oxygenates and if they have
been reformulated to reduce vehicle emis-sions.
As additional guidance, only use fuels
suited for your vehicle as explained in the
following description. .
Fuel should be unleaded and have an
octane rating no lower than that specified
in this manual. . Methanol (methyl or wood alcohol) is
sometimes mixed with unleaded gasoline.
Methanol can be used in your vehicle
ONLY if it does not exceed 5% of the fuel
mixture ANDif it is accompanied by
sufficient quantities of the proper cosol-
vents and corrosion inhibitors required to
prevent damage to the fuel system. Do not
use fuel containing methanol EXCEPT
under these conditions. . If undesirable driveability problems are
experienced and you suspect they may be
fuel related, try a different brand of gaso-
line before seeking service at your
SUBARU dealer. . Fuel system damage or driveability problems which result from the use of
improper fuel are not covered under the
SUBARU Limited Warranty.
CAUTION
Do not let fuel spill on the exterior
surfaces of the vehicle. Because
fuel may damage the paint, be sure
to wipe off any spilled fuel quickly.
Paint damage caused by spilled fuel
is not covered under the SUBARU
Limited Warranty.
& Fuel filler lid and cap
! Refueling
Only one person should be involved in
refueling. Do not allow others to approach
the area of the vehicle near the fuel filler
pipe while refueling is in progress.
Be sure to observe any other precautions
that are posted at the service station.

1. To open the fuel filler lid, pull the lid
release lever up. The lever is on the floor
at the left of the driver’s seat.
WARNING
Before opening the fuel filler cap,
first touch the vehicle body or a
metal portion of the fuel pump or
similar object to discharge any
static electricity that may be present
on your body. If your body is carry-
ing an electrostatic charge, there is
a possibility that an electric spark
could ignite the fuel, which could
burn you. To avoid acquiring a new
static electric charge, do not get
back into the vehicle while refueling
is in progress.
1) Open
2) Close
2. Remove the fuel filler cap by turning it slowly counterclockwise.
WARNING
. Gasoline vapor is highly flam-
mable. Before refueling, always
first stop the engine and close all
vehicle doors and windows.
Make sure that there are no
lighted cigarettes, open flames
or electrical sparks in the adja-
cent area. Only handle fuel out-
doors. Quickly wipe up any
spilled fuel.
. When opening the cap, grasp it
firmly and turn it slowly to the
left. Do not remove the cap
quickly. Fuel may be under pres-
sure and spray out of the fuel
filler neck, especially in hot
weather. If you hear a hissing
sound while you are removing
the cap, wait for the sound to
stop and then slowly open the
cap to prevent fuel from spraying
out and creating a fire hazard. Starting and operating
7-5
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7-6Starting and operating
3. Set the fuel filler cap on the cap holder
inside the fuel filler lid.
WARNING
. When refueling, insert the fuel
nozzle securely into the fuel filler
pipe. If the nozzle is lifted or not
fully inserted, its automatic stop-
ping mechanism may not func-
tion, causing fuel to overflow the
tank and creating a fire hazard. .
Stop refueling when the auto-
matic stop mechanism on the
fuel nozzle activates. If you con-
tinue to add fuel, temperature
changes or other conditions
may cause fuel to overflow from
the tank and create a fire hazard.
4. Stop filling the tank after the fuel filler
pump automatically stops. Do not add any
more fuel.
5. Put the cap back on, turn it clockwise
until you hear a clicking noise. Be certain
not to catch the tether under the cap whiletightening.
6. Close the fuel filler lid completely.
If you spill any fuel on the painted surface,
rinse it off immediately. Otherwise, the
painted surface could be damaged. NOTE . You will see the “
”sign in the fuel
gauge. This indicates that the fuel filler
door (lid) is located on the right side of
the vehicle.. If the fuel filler cap is not tightened
until it clicks or if the tether is caught
under the cap, the CHECK ENGINE
warning light/malfunction indicator
light may illuminate. Refer to “CHECK
ENGINE warning light/Malfunction in- dicator light
”F 3-15.
CAUTION
. Never add any cleaning agents to
the fuel tank. The addition of a
cleaning agent may cause da-
mage to the fuel system.
. After refueling, turn the cap to the
right until it clicks to ensure that
it is fully tightened. If the cap is
not securely tightened, fuel may
leak out while the vehicle is being
driven or fuel spillage could
occur in the event of an accident,
creating a fire hazard.
. Do not let fuel spill on the exterior
surfaces of the vehicle. Because
fuel may damage the paint, be
sure to wipe off any spilled fuel
quickly. Paint damage caused by
spilled fuel is not covered under
the SUBARU Limited Warranty.
. Always use a genuine SUBARU
fuel filler cap. If you use the
wrong cap, it may not fit or have
proper venting and your fuel tank
and emission control system
may be damaged. It could also
lead to fuel spillage and a fire.
. Immediately put fuel in the tank

whenever the low fuel warning
light illuminates. Engine misfires
as a result of an empty tank
could cause damage to the en-gine.State emission testing (U.S. only)
WARNING
Testing of an All-Wheel Drive model
must NEVER be performed on a
single two-wheel dynamometer. At-
tempting to do so will result in
uncontrolled vehicle movement and
may cause an accident or injuries to
persons nearby.
CAUTION
. At state inspection time, remem-
ber to tell your inspection or
service station in advance not to
place your SUBARU AWD vehicle
on a two-wheel dynamometer.
Otherwise, serious transmission
damage will result.
. Resultant vehicle damage due to
improper testing is not covered
under the SUBARU Limited War-
ranty and is the responsibility of
the state inspection program or
its contractors or licensees.
California and a number of federal states
have Inspection/Maintenance programs to inspect your vehicle
’s emission control
system. If your vehicle does not pass this
test, some states may deny renewal of
your vehicle ’s registration.
Your vehicle is equipped with a computer
that monitors the performance of the engine ’s emission control system. Certi-
fied emission inspectors will inspect the
On-Board Diagnostic (OBDII) system as
part of the state emission inspection
process. The OBDII system is designed
to detect engine and transmission pro-
blems that might cause the vehicle emis-
sions to exceed allowable limits. OBDII
inspections apply to all 1996 model year
and newer passenger cars and trucks.
Over 30 states plus the District of Colum-
bia have implemented emission inspec-
tion of the OBDII system. . The inspection of the OBDII system
consists of a visual operational check of the “CHECK ENGINE ”warning light/mal-
function indicator light (MIL) and an
examination of the OBDII system with an
electronic scan tool. . A vehicle
passes the OBDII system
inspection if proper operation of the “ CHECK ENGINE ”warning light is ob-
served, there are no stored diagnostic
trouble codes, and the OBDII readiness
monitors are all complete. Starting and operating
7-7
– CONTINUED –

7-8Starting and operating
.A vehiclefails the OBDII inspection if
the “CHECK ENGINE ”warning light is not
properly operating (light is illuminated or is
not working due to a burned out bulb) or
there is one or more diagnostic trouble
codes stored in the vehicle ’s computer.
. A state emission inspection may reject
(not pass or fail) a vehicle if the number of
OBDII system readiness monitors “NOT
READY ”is greater than one. If the
vehicle ’s battery has been recently re-
placed or disconnected, the OBDII system
inspection may indicate that the vehicle is
not ready for the emission test. Under this
condition, the vehicle driver should be
instructed to drive his/her vehicle for a few
days to reset the readiness monitors and
return for an emission re-inspection. . Owners of rejected or failing vehicles
should contact their SUBARU Dealer for service.
Some states still use dynamometers in
their emission inspection program. A
dynamometer is a treadmill or roller-like
testing device that allows your vehicle ’s
wheels to turn while the vehicle remains in
one place. Prior to your vehicle being put
on a dynamometer, tell your emission
inspector
not to place your SUBARU
AWD vehicle on a two-wheel dynam-
ometer. Otherwise, serious transmis-
sion damage will result. The U.S. Environmental Protection
Agency (EPA) and states using two-wheel
dynamometers in their emission testing
program have EXEMPTED SUBARU
AWD vehicles from the portion of the
testing program that involves a two-wheel
dynamometer. There are some states that
use four-wheel dynamometers in their
testing program. When properly used, this
equipment should not damage a SUBARU
AWD vehicle.
Under no circumstances should the rear
wheels be jacked off the ground, nor
should the driveshaft be disconnected for
state emission testing.
Preparing to drive
You should perform the following checks
and adjustments every day before you
start driving.
1. Check that all windows, mirrors, and
lights are clean and unobstructed.
2. Check the appearance and condition
of the tires. Also check tires for properinflation.
3. Look under the vehicle for any sign of leaks.
4. Check that the hood, trunk (4-door)
and rear gate (5-door) are fully closed.
5. Check the adjustment of the seat.
6. Check the adjustment of the inside
and outside mirrors.
7. Fasten your seatbelt. Check that your
passengers have fastened their seatbelts.
8. Check the operation of the warning
and indicator lights when the ignition
switch is turned to the
“ON ”position.
9. Check the gauges, indicator and warn-
ing lights after starting the engine.
NOTE
Engine oil, engine coolant, brake fluid,
washer fluid and other fluid levels
should be checked daily, weekly or at
fuel stops.

Starting the engine
CAUTION
Do not operate the starter motor
continuously for more than 10 sec-
onds. If the engine fails to start after
operating the starter for 5 to 10
seconds, wait for 10 seconds or
more before trying again.
NOTE
It may be difficult to start the engine
when the battery has been discon-
nected and reconnected (for mainte-
nance or other purposes). This diffi-
culty is caused by the electronically
controlled throttle ’s self-diagnosis
function. To overcome it, keep the
ignition switch in the “ON ”position
for approximately 10 seconds before
starting the engine.
1. Apply the parking brake.
2. Turn off unnecessary lights and ac- cessories.
3. Depress the clutch pedal to the floor
and shift the shift lever into neutral. Hold
the clutch pedal to the floor while starting
the engine.
The starter motor will only operate when the clutch pedal is depressed fully to the
floor.
4. Turn the ignition switch to the
“ON ”
position and check the operation of the
warning and indicator lights. Refer to“ Warning and indicator lights ”F 3-12.
5. Turn the ignition switch to the “START ”
position without depressing the accelera-
tor pedal. Release the key immediately
after the engine has started.
If the engine does not start, try the following.
(1) Turn the ignition switch to the“OFF ”position and wait for at least
10 seconds. After checking that the
parking brake is firmly set, turn the
ignition switch to the “START ”position
while depressing the accelerator pedal
slightly (approximately a quarter of the
full stroke). Release the accelerator
pedal as soon as the engine starts.
(2) If this fails to start the engine, turn
the ignition switch back to the “OFF ”
position and wait for at least 10
seconds. Then fully depress the accel-
erator pedal and turn the ignition
switch to the “START ”position. If the
engine starts, quickly release the
accelerator pedal.
(3) If this fails to start the engine, turn
the ignition switch again to the “OFF ”
position. After waiting for 10 seconds or longer, turn the ignition switch to the“
START ”position without depressing
the accelerator pedal.
(4) If the engine still refuses to start,
contact your nearest SUBARU dealer
for assistance.
6. Confirm that all warning and indicator
lights have turned off after the engine has
started. The fuel injection system auto-
matically lowers the idle speed as the
engine warms up. Starting and operating
7-9

7-10Starting and operating
Stopping the engine
The ignition switch should be turned off
only when the vehicle is stopped and the
engine is idling.
WARNING
Do not stop the engine when the
vehicle is moving. This will cause
loss of power to the power steering
and the brake booster, making steer-
ing and braking more difficult. It
could also result in accidental acti-
vation of the “LOCK ”position on the
ignition switch, causing the steering
wheel to lock. Remote engine start system
(dealer option)
WARNING
. Do not start the engine using the
remote start system in an en-
closed environment (e.g., in a
closed garage). Prolonged opera-
tion of a motor vehicle in an
enclosed environment can cause
a harmful build-up of Carbon
Monoxide. Carbon Monoxide is
harmful to your health. Exposure
to high levels of Carbon Monox-
ide can cause headaches, dizzi-
ness or in extreme cases uncon-
sciousness and/or death.
. Before performing any servicing
of the vehicle, temporarily place
the remote engine start system in
service mode to prevent the
system from unexpectedly start-
ing the engine.
& Starting your vehicle
The remote engine start system is acti-
vated by pressing the “
”button twice
within 3 seconds on your remote engine
start transmitter. The system will check
certain pre-conditions before starting, and
if all safety parameters are correct, the
engine will start within 5 seconds. While
the vehicle is operating via remote engine
start, the vehicle ’s power window features
will be disabled. Also, the system has a
timer and will shut down after 15 minutes if
you do not operate the vehicle. Press and
hold the “
”button for 2 seconds again to
turn the vehicle off. If the vehicle ’s starter
cranks but does not start or starts and
stalls, the remote engine start system will
power off then attempt to start the vehicle

an additional four times. If the vehicle fails
to start after the additional attempts, the
remote engine start system will abort and
return to a non-activated state. &Remote start safety features
For safety and security reasons, the
system will fail to start and beep the horn
twice or shut down the engine during
remote start operation if any of the
following conditions occur. . The brake pedal is depressed before
the vehicle ignition switch is turned “on ”.
. The key was already in the ignition
switch.. The engine hood is opened.
. The vehicle ’s engine idle speed has
reached a level over 3,000 rpm.. The alarm is triggered by opening a
door or the rear gate.
NOTE . The security indicator light on the
combination meter will stop flashing
while under remote engine start opera-
tion, but the vehicle is still protected.. If the vehicle is entered during
remote engine start operation, the
system will not record entry in the
alarm history. &
Entering the vehicle while it
is running via remote start
1. Unlock the vehicle doors using the
remote keyless entry system. If the vehi-cle ’s doors are unlocked manually using
the key, the vehicle ’s alarm system will
trigger and the remote engine start system
will turn off. Inserting the key into the
ignition switch and turning it to the “ON ”
position or pressing the unlock button “
”
on the remote keyless entry transmitter
will disarm the alarm system. Refer to“ Alarm system ”F 2-15.
2. Enter the vehicle. Do not depress the
brake pedal.
3. Insert the key into the ignition switch
and turn to the “ON ”position. If the ignition
switch is accidentally turned to the“ START ”position, the system ’s “starter
anti-grind ”feature will prevent the starter
from re-cranking.
4. Depress the brake pedal. The remote
starter disengages, the vehicle ’s power
window features are re-enabled and the
vehicle will operate normally.
& Entering the vehicle follow-
ing remote engine start shut-down
An alarm trigger may occur if the vehicle is
opened by the remote keyless entry transmitter within a few seconds immedi-
ately following remote engine start shut-down. &
Pre-heating or pre-cooling
the interior of the vehicle
Before exiting the vehicle, set the tem-
perature controls to the desired setting
and operation. After the system starts the
vehicle, the heater or air-conditioning will
activate and heat or cool the interior to
your setting. & Service mode
In service mode, the remote start function
is temporarily disabled to prevent the
system from unexpectedly starting the
engine while being serviced. ! To engage the service mode
Turntheignitionswitchtothe “ON ”
position, depress and hold the brake
pedal, then press and release the “
”
button on the remote engine start trans-
mitter three times. The system will pause
for 1 second and then flash the turn signal
lights and honk the horn three times
indicating that the system is in service
mode. When attempting to activate the
remote start system while in service
mode, the turn signal lights will flash and
the horn will honk two times and will not Starting and operating
7-11
– CONTINUED –

7-12Starting and operating
start. !To disengage the service mode
Turn the ignition switch to the “ON ”
position, depress and hold the brake
pedal, then press and release the “
”
button on the remote engine start trans-
mitter three times. The system will pause
for 1 second and flash the turn signal
lights once indicating that the system has
exited service mode.
NOTE
When taking your vehicle in for service,
it is recommended that you inform the
service personnel that your vehicle is
equipped with a remote engine startsystem. & Remote engine start trans-
mitter programming and pro-
grammable feature option
New transmitters can be programmed to
the remote engine start system in the
event that remote engine start transmitters
are lost, stolen or damaged. The remote
engine start system also has one pro-
grammable feature that can be adjusted
for user preference.
The remote engine start system can be
programmed to either make an audible
horn chirp upon remote start activation or not. Remote engine start transmitter pro-
gramming and feature programming can
be adjusted using the following procedure.
1. Open the driver
’s door (the driver ’s
door must remain opened throughout the
entire process).
2. Insert the key into the vehicle ’s ignition
switch and turn to the “ON ”position.
3. Locate the small black programming
button behind the fuse box cover, on the
driver ’s side left under the dashboard
panel.
4. Press and hold the black programming
button for 10 to 15 seconds. The horn will
honk and the turn signal lights will flash
three times to indicate that the system has
entered programming mode. At this point
you can proceed to either step 5 or step 6.
5. To program a remote engine start
transmitter: press and release the “
”
button on each transmitter. The horn will
honk and the turn signal lights will flash
one time to indicate a successful trans-
mitter learn each time the “
”button is
pressed. You can program up to eight transmitters.
6. To toggle the Horn Confirmation chirps
ON/OFF: depress and release the brake
pedal to toggle the feature. The horn will
chirp and the turn signal lights will flash
one time to indicate Confirmation Horn
Chirps are “OFF ”. The horn will honk and the turn signal lights will flash 2 times to
indicate Confirmation Horn Chirps are“
ON ”. Depressing the brake pedal repeat-
edly will toggle the feature ON or OFF
each time.
7. To exit the remote engine start trans-
mitter and feature programming mode,
turn the ignition switch to the “LOCK ”
position, remove the key from the ignition
switch and test operation of the remote
engine start transmitter(s) and horn con-
firmation feature.
& System maintenance
! Changing the batteries
CAUTION
. Do not let dust, oil or water get on
or in the remote engine start
transmitter when replacing the
battery.
. Be careful not to damage the
printed circuit board in the re-
mote engine start transmitter
when replacing the battery.
. Be careful not to allow children to
touch the battery and any re-
moved parts; children could
swallow them.
. There is a danger of explosion if