2011 SUBARU IMPREZA WRX alternator

3-18Instruments and controls
approximately 2 seconds when the igni-
tion switch is turned to the “ON ”position.
After that, this indicator light/warning light
changes to BLUEand maintains illumina-
tion in BLUE. This BLUE illuminated light
turns off when the engine is warmed up
sufficiently.
If the engine coolant temperature in-
creases over the specified range, the
indicator light/warning light blinks inRED . At this time, the engine is close to
overheating.
If the engine coolant temperature in-
creases further, the indicator light/warning
light illuminates in REDcontinuously. At
this time, the engine may be overheating.
When the indicator light/warning light
blinks in REDor illuminates in RED, safely
stop the vehicle as soon as possible, and
refer to the emergency steps to take in the
case of engine overheating. Refer to“ Engine overheating ”F 9-13. After that,
have the system checked by your nearest
SUBARU dealer.
Also, if the indicator light/warning light
often blinks in RED, the electrical system
may be malfunctioning. Contact your
SUBARU dealer for an inspection. NOTE
If the engine is restarted after a certain
driving condition, this indicator light/
warning light may illuminate in RED.
However, this is not a malfunction if the
indicator light/warning light turns off
after a short time. &
Charge warning light
If this light illuminates when the engine is
running, it may indicate that the charging
system is not working properly.
If the light illuminates while driving or does
not turn off after the engine starts, stop the
engine at the first safe opportunity and
check the alternator belt. If the belt is
loose, broken or if the belt is in good
condition but the light remains illuminated,
contact your nearest SUBARU dealer
immediately. &Oil pressure warning light
If this light illuminates when the engine is
running, it may indicate that the engine oil
pressure is low and the lubricating system
is not working properly.
If the light illuminates while driving or does
not turn off after the engine starts, stop the
engine at the first safe opportunity and check the engine oil level. If the oil level is
low, add oil immediately. If the engine oil is
at the proper level but the light remains
illuminated, contact your nearest
SUBARU dealer immediately.
For details about checking the engine oil
level or adding the engine oil, refer to“
Engine oil ”F 11-10.
CAUTION
Do not operate the engine with the
oil pressure warning light illumi-
nated. This may cause serious en-
gine damage.
& AT OIL TEMP warning
light (AT models)
If this light illuminates when the engine is
running, it may indicate that the automatic
transmission fluid temperature is too hot.
If the light illuminates while driving, im-
mediately stop the vehicle in a safe place
and let the engine idle until the warning
light turns off. !Automatic transmission control
system warning
If the “AT OIL TEMP ”warning light flashes
after the engine starts, it may indicate that
the automatic transmission control system

11-20Maintenance and service
&Recommended spark plugs
For the recommended spark plugs, refer to “Electrical system ”F 12-3. Drive belts
1) Power steering oil pump pulley
2) Front side belt
3) Alternator pulley
4) Air conditioner compressor pulley
5) Rear side belt
6) Crank pulley
A) 22 lbf (98 N, 10 kgf)
CAUTION
The front side belt, which runs in
conjunction with the following com-
ponents, must be used within the
specified deflection. . Power steering oil pump pulley
. Alternator pulley
. Crank pulley Check the deflection of the front
side belt and if there is any loosen-
ess, cracks, wear or unusual noise
on the front side belt, contact your
SUBARU dealer.
Continuing to use the vehicle with
the belt outside of the specification
may cause the engine to malfunc-
tion and the above components tomalfunction.
To check the deflection of the front side
belt, place a straightedge (ruler) across
two adjacent pulleys (alternator pulley and
crank pulley) and apply a force of 22 lbf
(98 N, 10 kgf) midway between the pulleys
by using a spring scale. The belt deflec-
tion should be the amount specified. If the
front side belt is loose, cracked or worn,
contact your SUBARU dealer. in (mm)
Deflection
New belt Used belt
A 0.28
–0.35
(7.0 –9.0) 0.35
–0.43
(9.0 –11.0)
The rear side belt is a stretch-type belt,
therefore the deflection does not need to
be checked. If there are cracks or wear
confirmed on the belts and a squeaking
noise is heard from them, contact your
SUBARU dealer.

&Engine
Engine model EJ253
(2.5 L, SOHC, non-turbo) EJ255
(2.5 L, DOHC, turbo, except STI) EJ257
(2.5 L, DOHC, turbo, STI)
Engine type Horizontally opposed, liquid cooled 4 cylinder, 4-stroke gasoline engine
Displacement cc (cu-in) 2,457 (150)
Bore 6Stroke in (mm) 3.963.1 (99.5 679.0)
Compression ratio 10.0 : 1 8.4 : 1 8.2 : 1
Firing order 1
–3 –2–4
& Electrical system
Battery type and capacity (5HR) MT 12V-48AH (55D23L)
AT 12V-52AH (65D23L)
Alternator Non-turbo models 12V-90A
Turbo models 12V-110A
Spark plugs Non-turbo models FR5AP-11 (NGK)
Turbo models SILFR6A (NGK)
AT: Automatic transmission
MT: Manual transmission Specifications
12-3
– CONTINUED –

12-14Specifications
&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