check engine light SUBARU IMPREZA WRX 2012 4.G Owner's Manual

a loss of control of the vehicle. Keep
driving straight ahead while gradually
reducing speed. Then slowly pull off the
road to a safe place. &Brake system
! Two separate circuits
Your vehicle has two separate circuit
brake systems. Each circuit works diag-
onally across the vehicle. If one circuit of
the brake system should fail, the other half
of the system still works. If one circuit fails,
the brake pedal will go down much closer
to the floor than usual and you will need to
press it down much harder. And a much
longer distance will be needed to stop thevehicle. ! Brake booster
The brake booster uses engine manifold
vacuum to assist braking force. Do not
turn off the engine while driving because
that will turn off the brake booster, result-
ing in poor braking power.
The brakes will continue to work even
when the brake booster completely stops
functioning. If this happens, however, you
will have to depress the pedal much
harder than normal and the braking dis-
tance will increase. !
Brake assist system
WARNING
Do not be overconfident about the
brake assist. It is not a system that
brings more braking ability to the
vehicle beyond its braking capabil-
ity. Always use the utmost care
when driving regarding vehicle
speed and safe distance.
CAUTION
When you need to brake suddenly,
continue depressing the brake pedal
strongly to bring the effect of the
brake assist.
Brake assist is a driver assistance system.
It assists the brake power when the driver
cannot depress the brake pedal strongly
and the brake power is insufficient.
Brake assist generates the brake power
according to the speed at which the driver
depresses the brake pedal. NOTE
When you depress the brake pedal
strongly or suddenly, the following
phenomena occur. However, even
though these occur, they do not indi- cate any malfunctions, and the brake
assist system is operating properly. .
You might feel that the brake pedal
is applied by lighter force and gener-
ates a greater braking force.. You might hear the sound of ABS
operating from the engine compart-ment. & Disc brake pad wear warning indicators
The disc brake pad wear warning indica-
tors on the disc brakes give a warning
noise when the brake pads are worn.
If a squeaking or scraping noise is heard
from the disc brakes while braking, im-
mediately have your vehicle checked by
your SUBARU dealer. Starting and operating
7-25

7-26Starting and operating
ABS (Anti-lock Brake Sys- tem)
The ABS system prevents the lock-up of
wheels which may occur during sudden
braking or braking on slippery road sur-
faces. This helps prevent the loss of
steering control and directional stability
caused by wheel lock-up.
When the ABS system is operating, you
may hear a chattering noise or feel a slight
vibration in the brake pedal. This is normal
when the ABS operates.
The ABS system will not operate when the
vehicle speed is below approximately 6
mph (10 km/h).
WARNING
Always use the utmost care in driving –overconfidence because
youaredrivingwithanABS
equipped vehicle could easily lead
to a serious accident.
CAUTION
. The ABS system does not always
decrease stopping distance. You
should always maintain a safe
following distance from other vehicles.
. When driving on badly surfaced
roads, gravel roads, icy roads, or
over deep newly fallen snow,
stopping distances may be long-
er for a vehicle with the ABS
system than one without. When
driving under these conditions,
therefore, reduce your speed and
leave ample distance from othervehicles.
. When you feel the ABS system
operating, you should maintain
constant brake pedal pressure.
Do not pump the brake pedal
since doing so may defeat the
operation of the ABS system.
& ABS system self-check
Just after the vehicle is started, you may
feel on the brake pedal a vibration similar
to when the ABS operates, and you may
also hear the sound of the ABS working
from the engine compartment. This is
caused by an automatic functional test of
the ABS system being carried out and
does not indicate any abnormal condition. & ABS warning light
Refer to “ABS warning light ”F 3-18. Electronic Brake Force Dis-
tribution (EBD) system
The EBD system maximizes the effective-
ness of the brakes by allowing the rear
brakes to supply a greater proportion of
the braking force. It functions by adjusting
the distribution of braking force to the rear
wheels in accordance with the vehicle
’s
loading condition and speed.
The EBD system is an integral part of the
ABS system and uses some of the ABSsystem ’s components to perform its func-
tion of optimizing the distribution of brak-
ing force. If any of the ABS components
used by the EBD system malfunction, the
EBD system also stops working.
When the EBD system is operating, you
may hear a chattering noise or feel a slight
vibration in the brake pedal. This is normal
and does not indicate a malfunction.

&Steps to take if EBD system malfunctions
If a malfunction occurs in the EBD system,
the system stops working and the brake
system warning light and ABS warning
light illuminate simultaneously.
The EBD system may be malfunctioning if
the brake system warning light and ABS
warning light illuminate simultaneously
during driving.
Even if the EBD system malfunctions, the
conventional braking system will still func-
tion. However, the rear wheels will be
more prone to locking when the brakes
are applied harder than usual and thevehicle ’s motion may therefore become
somewhat harder to control.
If the brake system warning light and ABS warning light illuminate simultaneously,
take the following steps.
1. Stop the vehicle in the nearest safe,
flat location.
2. Shut down the engine, apply the
parking brake, and then restart it.
3. Release the parking brake. If both
warning lights turn off, the EBD system
may be malfunctioning. Drive carefully to
the nearest SUBARU dealer and have the
system inspected.
4. If both warning lights illuminate again
and remain illuminated after the engine
has been restarted, shut down the engine
again, apply the parking brake, and check
the brake fluid level. Refer to
“Brake fluid ”
F 11-18.
5. If the brake fluid level is not below the“ MIN ”mark, the EBD system may be
malfunctioning. Drive carefully to the
nearest SUBARU dealer and have the
system inspected.
6. If the brake fluid level is below the “ MIN ”mark, DO NOT drive the vehicle.
Instead, have the vehicle towed to the
nearest SUBARU dealer for repair.
WARNING
. Driving with the brake system
warning light illuminated is dan- gerous. This indicates your brake
system may not be working
properly. If the light remains
illuminated, have the brakes in-
spected by a SUBARU dealer
immediately.
. If at all in doubt about whether
the brakes are operating prop-
erly, do not drive the vehicle.
Have your vehicle towed to the
nearest SUBARU dealer for re-
pair. Starting and operating
7-27

&When checking or servicing
in the engine compartment
while the engine is running
WARNING
A running engine can be dangerous.
Keep your fingers, hands, clothing,
hair and tools away from the cooling
fan, belts and any other moving
engine parts. Removing rings,
watches and ties is advisable. Engine hood
WARNING
Always check that the hood is
properly locked before you start
driving. If it is not, it might fly open
while the vehicle is moving and
block your view, which may cause
an accident and serious bodily in-
jury.
To open the hood:
1. If the wiper blades are lifted off the
windshield, return them to their originalposition.
2. Pull the hood release knob under the
instrument panel.
3. Release the secondary hood release
by moving the lever between the front
grille and the hood toward the left.
4. Lift up the hood.
To close the hood:
1. Lower the hood to a height of approxi-
mately 5.9 in (15 cm) above its closed
position and then let it drop.
2. After closing the hood, be sure the
hood is securely locked.
If this does not close the hood, release it
from a slightly higher position. Do not push
thehoodforciblytocloseit.Itcould
deform the metal. Maintenance and service
11-5

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-

11-20Maintenance and service
Brake booster
If the brake booster does not operate as
described in the following, have it checked
by your SUBARU dealer.
1. With the engine off, depress the brake
pedal several times, applying the same
pedal force each time. The distance the
pedal travels should not vary.
2. With the brake pedal depressed, start
the engine. The pedal should move
slightly down to the floor.
3. With the brake pedal depressed, stop
the engine and keep the pedal depressed
for 30 seconds. The pedal height should
not change.
4. Start the engine again and run for
approximately one minute then turn it off.
Depress the brake pedal several times to
check the brake booster. The brake
booster operates properly if the pedal
stroke decreases with each depression. NOTE
For vehicles equipped with the brake
assist system, when you depress the
brake pedal strongly or suddenly, you
might feel that lighter depression of the
brake pedal generates a greater brak-
ing force. However, even though these
occur, they do not indicate any mal- functions, and the brake assist system
is operating properly.
Brake assist is not a system that brings
more braking ability to the vehicle
beyond its breaking capability.
Brake pedal
Check the brake pedal free play and
reserve distance according to the main-
tenance schedule in the
“Warranty and
Maintenance Booklet ”.
& Checking the brake pedal
free play
1) 0.02 –0.08 in (0.5 –2.0 mm)
Stop the engine and firmly depress the
brake pedal several times. Lightly pull the
brake pedal up with one finger to check
the free play with a force of less than 2 lbf
(10 N, 1 kgf).
If the free play is not within proper
specification, contact your SUBARU deal-
er.

&Checking the brake pedal
reserve distance
1) More than 2.56 in (65 mm)
Depress the pedal with a force of approxi-
mately 66 lbf (294 N, 30 kgf) and measure
the distance between the upper surface of
the pedal pad and the floor.
When the measurement is smaller than
the specification, or when the pedal does
not operate smoothly, contact with your
SUBARU dealer. Clutch pedal
Check the clutch pedal free play and
reserve distance according to the main-
tenance schedule in the
“Warranty and
Maintenance Booklet ”.
& Checking the clutch function
Check the clutch engagement and disen-gagement.
1. With the engine idling, check that there
are no abnormal noises when the clutch
pedal is depressed, and that shifting into
1st or reverse feels smooth.
2. Start the vehicle by releasing the pedal
slowly to check that the engine and
transmission smoothly couple without
any sign of slippage. &
Checking the clutch pedal
free play1) 0.16 –0.43 in (4.0 –11.0 mm)
Lightly depress the clutch pedal down with
your finger until you feel resistance, and
check the free play.
If the free play is not within proper
specification, contact your SUBARU deal-
er. Maintenance and service
11-21

11-22Maintenance and service
Hill start assist system
Ensure that the Hill start assist system
operates properly under the followingcircumstances:
1. Stop the vehicle on an uphill grade by
depressing the brake pedal and clutch
pedal, with the engine running.
2. Make sure that the vehicle does not
move backward even after the brake
pedal is released.
3. Then make sure the vehicle starts
climbing the grade by following the normal
starting procedures.
If the Hill start assist system does not
operate as described above, contact with
your SUBARU dealer. Replacement of brake pad
and lining
The disc brakes have audible wear
indicators on the brake pads. If the brake
pads wear close to their service limit, the
wear indicator makes a very audible
scraping noise when the brake pedal isapplied.
If you hear this scraping noise each time
you apply the brake pedal, have the brake
pads serviced by your SUBARU dealer as
soon as possible.
CAUTION
If you continue to drive despite the
scraping noise from the audible
brake pad wear indicator, it will result in the need for costly brake
rotor repair or replacement.
& Breaking-in of new brake
pads and linings
When replacing the brake pad or lining,
use only genuine SUBARU parts. After
replacement, the new parts must be
broken in as follows. ! Brake pad and lining
While maintaining a speed of 30 to 40
mph (50 to 65 km/h), step on the brake
pedal lightly. Repeat this five or moretimes. ! Parking brake lining
1. Drive the vehicle at a speed of
approximately 22 mph (35 km/h).
2. With the parking brake release button
pushed in, pull the parking brake lever
SLOWLY and GENTLY (pulling with a
force of approximately 33.7 lbf [150 N,
15.3 kgf]).
3. Drive the vehicle for approximately
220 yards (200 meters) in this condition.
4. Wait 5 to 10 minutes for the parking
brake to cool down. Repeat this proce-dure.
5. Check the parking brake stroke. If the
parking brake stroke is out of the specified

&Lubricants
NOTE
Each quantity indicated here is only a guideline. The necessary quantity for replacement may differ slightly depending on the
temperature and other factors. ! Engine oil
For checking, adding and replacing procedure, or other details, refer to “Engine oil ”F 11-8.
Oil grade SAE viscosity No. and
applicable temperature Engine oil capacity
API classification SM or SN
with the words “
ENERGY CONSERVING ”or
“ RESOURCE CONSERVING ”orILSAC GF-4 or GF-5, which can be
identified with the ILSAC certification
mark (Starburst mark) 5W-30 synthetic
oil is the required oil for
optimum engine performance and pro-
tection. Conventional oil may be used if
synthetic oil is unavailable.
*: 10W-30, 10W-40, 5W-30 or 5W-40
conventional oil may be used if replen-
ishment is needed but should be changed
to 5W-30 synthetic oil at the next oil change.
· When adding the oil from L to F level:
1.1 US qt (1.0 liter, 0.9
Imp qt)
· When changing the oil and oil filter:
- Except STI:
4.4 US qt (4.2 liters, 3.7
Imp qt)
- STI:
4.5 US qt (4.3 liters, 3.8
Imp qt) Specifications
12-5
– CONTINUED –

12-8Specifications
&Engine coolant
NOTE
Each quantity indicated here is only a guideline. The necessary quantity for replacement may differ slightly depending on the
temperature and other factors.
Model Coolant capacity Coolant type
Turbo models Except STI 7.8 US qt (7.4 liters, 6.5 Imp qt)
SUBARU Super Coolant
STI 8.1 US qt (7.7 liters, 6.8 Imp qt)
For the checking, adding and replacing procedure, or other details, refer to “Cooling system ”F 11-11.