2006 SUBARU IMPREZA WRX transmission fluid

Instruments and controls 3-17
– CONTINUED –
is at the proper level but the light remains
on, contact your nearest SUBARU dealer
immediately.
AT OIL TEMPerature
warning light (AT vehi-
cles)
The AT oil temperature warning light
comes on when the ignition switch is
turned to the
“ON ” position and goes out
after approximately two seconds.
If this light comes on when the engine is
running, it may indicate that the automatic
transmission fluid temperature is too hot.
If the light comes on while driving, it is un-
necessary to stop the vehicle, but avoid
driving up steep grades or in stop and go
traffic.
Automatic transmission control
system warning
If the light flashes after the engine starts,
it may indicate that the automatic trans-
mission control system is not working
properly. Contact your nearest SUBARU dealer for service immediately.
Rear differential oil tem-
perature warning light
(WRX-STI)
If this light comes on when the engine is
running, it may indicate that the rear differ-
ential oil temperature is too hot.
At this time, the driver
’s control center dif-
ferential will automatically cancel the cur-
rent torque-distribution ratio setting and
adopts its minimum ratio.
If the light comes on while driving, reduce
vehicle speed and stop the vehicle at the
nearest safe place.
Park the vehicle for several minutes. After
the light goes out, you can start driving.
If the light does not go out, contact the
nearest SUBARU dealer for service.
NOTE
If the tire pressures are not correct
and/or the tires are not all the same
size and brand, the rear differential will
be heavily loaded when the vehicle is
driven, resulting in an abnormally high
oil temperature.
The rear differential oil will deterio-
rate if its temperature increases
enough for the rear differential oil tem-
perature warning light to come on. It is
advisable to have the rear differential
oil replaced as soon as possible.
ABS warning light
The ABS warning light comes on when the
ignition switch is turned to the “ON ” posi-
tion and goes out after approximately two
seconds.
This is an indication that the ABS system
is working properly.
Do not operate the engine with the
oil pressure warning light on. This
may cause serious engine damage.
Reduce vehicle speed and park the
vehicle in a safe place as soon as
possible if the R.DIFF TEMP light
comes on. Continued driving with
this light on can damage the rear dif-
ferential and other parts of the pow-
ertrain.
If the warning light behaves as fol-
lows, the ABS system may not work
properly.
When the warning light is on, the
ABS function shuts down; however,
the conventional brake system con-
tinues to operate normally.
(U.S.)
(Canada)

7-6 Starting and operating
The EPA has issued regulations for in-
specting the On-Board Diagnostic (OBD)
system as part of the state emissions in-
spection. The OBD system is designed to
detect engine and transmission problems
that might cause vehicle emissions to ex-
ceed allowable limits. These inspections
apply to all 1996 model year and newer
passenger cars and light trucks. Over 30
states plus the District of Columbia have
implemented the OBD system inspection.
The inspection of the OBD system con-
sists of a visual operational check of the “ CHECK ENGINE ” warning light/malfunc-
tion indicator lamp (MIL) and an examina-
tion of the OBD system with an electronic
scan tool while the engine is running.
A vehicle passes the OBD system in-
spection if proper the “CHECK ENGINE ”
warning light/MIL illumination is observed,
there is no stored diagnostic trouble
codes, and the OBD system readiness
monitors are complete.
A vehicle fails the OBD inspection if the
“ CHECK ENGINE ” warning light/MIL is
not properly operating or there is one or
more diagnostic trouble codes stored in
vehicle ’s computer with the “CHECK EN-
GINE ” warning light/MIL illuminated.
A state emission inspection may reject
(not pass or fail) a vehicle if the number of
OBD system readiness monitors “Not
Ready ” is greater than one. Under this
condition, the vehicle operator should be
instructed to drive his/her vehicle for a few
days to set the monitors and return for an
emission re-inspection.
Owners of rejected or failing vehicles
should contact their Subaru Dealer for
service.
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 proper infla-
tion.
3. Look under the vehicle for any sign of
leaks.
4. Check that the hood, trunk (Sedan)
and rear gate (Wagon) 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.
Resultant vehicle damage due to im-
proper testing is not covered under
the SUBARU Limited Warranty and
is the responsibility of the state in-
spection program or its contractors
or licensees.

7-16 Starting and operating
Automatic transmission
The automatic transmission is electroni-
cally controlled with 4-forward speeds and
1-reverse speed.
NOTE
When the engine coolant tempera-
ture is still low, your vehicle ’s automat-
ic transmission will up-shift at higher
engine speeds than when the coolant
temperature is sufficiently high in or-
der to shorten the warm-up time and
improve driveability. The gearshift tim-
ing will automatically shift to the nor-
mal timing after the engine has warmed
up.
Immediately after ATF (automatic
transmission fluid) is replaced, you
may feel that the automatic transmis-
sion operation is somewhat unusual.
This results from invalidation of data
the on-board computer has collected
and stored in memory to allow the
transmission to shift at the most ap-
propriate times for the current condi-
tion of your vehicle. Optimized shifting
will be restored as the vehicle contin-
ues to be driven for a while.
Selector lever for automatic
transmission
Do not shift from the “P ” or “N ” po-
sition into the “D ”, “3 ”, “2 ”, “1 ” or
“ R ” position while depressing the
accelerator pedal. This may cause
the vehicle to jump forward or back-
ward.
Shift into the “P ” or “R ” position
only after the vehicle is complete-
ly stopped. Shifting while the ve-
hicle is moving may cause dam-
age to the transmission.
Do not race the engine for more
than five seconds in any position
except the “N ” or “P ” position
when the brake is set or when
chocks are used in the wheels.
This may cause the automatic
transmission fluid to overheat.
Avoid shifting from one of the for-
ward driving positions into the “ R ” position or vice versa until the
vehicle has completely stopped.
Such shifting may cause damage
to the transmission.
When parking the vehicle, first se-
curely apply the parking brake
and then place the selector lever
in the “P ” position. Avoid parking
for a long time with the selector le-
ver in any other position as doing
so could result in a dead battery.
700034

7-18 Starting and operating
the original gear position.
While climbing a grade
When driving up hill, undesired upshift to
4th gear is prevented from taking place
when the accelerator pedal is released.
This minimizes the chances of subse-
quent downshifting to a lower gear when
accelerating again. This prevents repeat-
ed upshifting and downshifting resulting in
a smoother operation of the vehicle.
NOTE
The transmission may downshift to
2nd or 1st gear, depending on the way
the accelerator pedal is pressed to ac-
celerate the vehicle again.
While going down a hill
When descending a steep hill, depressing
the brake pedal will cause the transmis-
sion to downshift to 3rd gear, thus apply-
ing engine braking. Reacceleration for a
short time will cause the transmission to
upshift normally.
NOTE
In some cases, depressing the brake
pedal on a downhill grade does not re-
sult in an automatic downshift to 3rd
gear. This can happen when the auto-
matic transmission fluid temperature is
very low, for example, during driving shortly after the vehicle has been
parked for an extended period of time.
When the ATF temperature has risen to
a certain level, automatic downshift
normally takes place. In the meantime,
downshift manually for engine braking
as required.
Also, downshifting when braking
downhill will not occur at speeds
above approximately 48 mph (78 km/h).
3 (Third)
This position is for using engine braking
when going down a hill or for climbing a
grade.
The transmission automatically shifts into
a suitable gear from 1st to 3rd according
to the vehicle speed and the acceleration
you require.
When more acceleration is required in this
position, press the accelerator pedal fully
to the floor and hold that position. The
transmission will automatically downshift
to 2nd or 1st gear. When you release the
pedal, the transmission will return to the
original gear position.
2 (Second)
This position is for using engine braking
when going down a hill or for climbing a
steep grade.
In this position, the transmission holds in the 2nd gear.
Use this position when starting off from a
standstill on slippery road surfaces such
as mud or snow. It will ensure greater trac-
tion.
1 (First)
This position is for driving up or down very
steep grades, or driving through mud or
sand, or on slippery surfaces. In this posi-
tion, the transmission holds in the 1st
gear.
Maximum speeds
The following tables show the maximum
speeds that are possible with each differ-
ent gear.
When shifting down a gear, it is important
to confirm that the current vehicle speed is
not in excess of the Maximum Allowable
Speed of the gear which is about to be se-
lected.
mph (km/h)
Non-turbo models Turbo models
1 28 (45) 28 (45)
2 62 (100) 65 (104)
3 97 (156) 104 (167)

Driving tips 8-7
with your fingers and thumbs on the out-
side of the rim.
If driving through water, such as when
crossing shallow streams, first check the
depth of the water and the bottom of the
stream bed for firmness and ensure that
the bed of the stream is flat. Drive slowly
and completely through the stream. The
water should be shallow enough that it
does not reach the vehicle ’s undercar-
riage. Water entering the engine air intake
or the exhaust pipe or water splashing
onto electrical parts may damage your ve-
hicle and may cause it to stall. Never at-
tempt to drive through rushing water; re-
gardless of its depth, it can wash away the
ground from under your tires, resulting in
possible loss of traction and even vehicle
rollover.
Always check your brakes for effective-
ness immediately after driving in sand,
mud or water. Do this by driving slowly
and stepping on the brake pedal. Repeat
that process several times to dry out the
brake discs and brake pads.
Do not drive or park over or near flam-
mable materials such as dry grass or fall-
en leaves, as they may burn easily. The
exhaust system is very hot while the en-
gine is running and right after the engine
stops. This could create a fire hazard.
After driving through tall grass, mud, rocks, sand, rivers, etc., check that there
is no grass, bush, paper, rags, stones,
sand, etc. adhering to or trapped on the
underbody. Clear off any such matter from
the underbody. If the vehicle is used with
these materials trapped or adhering to the
underbody, a mechanical breakdown or
fire could occur.
Secure all cargo carried inside the vehi-
cle and make certain that it is not piled
higher than the seatbacks. During sudden
stops or jolts, unsecured cargo could be
thrown around in the vehicle and cause in-
jury. Do not pile heavy loads on the roof.
Those loads raise the vehicle ’s center of
gravity and make it more prone to tip over.
If you must rock the vehicle to free it
from sand or mud, depress the accelera-
tor pedal slightly and move the selector le-
ver back and forth between “D ” and “R ” re-
peatedly. Do not race the engine. For the
best possible traction, avoid spinning the
wheels when trying to free the vehicle.
When the road surface is extremely slip-
pery, you can obtain better traction by
starting the vehicle with the transmission
in 2nd than 1st (both for MT and AT).
Never equip your vehicle with tires larg-
er than those specified in this manual.
Frequent driving of an AWD vehicle un-
der hard-driving conditions such as rough
roads or off roads will necessitate more frequent replacement of engine oil, brake
fluid and transmission oil than that speci-
fied in the maintenance schedule de-
scribed in the
“Warranty and Maintenance
Booklet ”.
Remember that damage done to your
Subaru while operating it off-road and not
using common sense precautions such as
those listed above is not eligible for war-
ranty coverage.
Wash the vehicle ’s underbody after off-
road driving. Suspension components are
particularly prone to dirt buildup, so they
need to be washed thoroughly.

Driving tips 8-27
heating of your vehicle ’s brakes. Do not
make sudden downshifts.
When driving uphill in hot weather, the
air conditioner may turn off automatically
to protect the engine from overheating.
When driving uphill in hot weather, pay
attention to the water temperature gauge
pointer (for all vehicles) and AT OIL TEMP
warning light (for AT vehicles) since the
engine and transmission are relatively
prone to overheating under these condi-
tions. If the water temperature gauge
pointer approaches the OVERHEAT zone
or the AT OIL TEMP warning light illumi-
nates, immediately switch off the air con-
ditioner and stop the vehicle at the nearest
safe place. Refer to the “Engine overheat-
ing ” section in chapter 9, and “Warning
and indicator lights ” section in chapter 3.
If your vehicle has an automatic trans-
mission, avoid using the accelerator pedal
to stay stationary on an uphill slope in-
stead of using the parking brake or foot
brake. That may cause the transmission
fluid to overheat.
If your vehicle has an automatic trans-
mission, place the selector lever as fol-
lows:
Uphill slopes: “D ” position
Downhill slopes: A low-speed gear posi-
tion to use engine braking
Parking on a grade
Always block the wheels under both vehi-
cle and trailer when parking. Apply the
parking brake firmly. You should not park
on a hill or slope. But if parking on a hill or
slope cannot be avoided, you should take
the following steps:
1. Apply the brakes and hold the pedal
down.
2. Have someone place wheel blocks un-
der both the vehicle and trailer wheels.
3. When the wheel blocks are in place, re-
lease the regular brakes slowly until the
blocks absorb the load.
4. Apply the regular brakes and then ap-
ply the parking brake; slowly release the
regular brakes.
5. Shift into 1st or reverse gear (manual
transmission) or “P ” (automatic transmis-
sion) and shut off the engine.

11
Maintenance and service
Maintenance schedule ....................................... 11-3
Maintenance precautions ........................... ....... 11-3
Before checking or servicing in the engine compartment ....................................... ................. 11-4
When you do checking or servicing in the engine
compartment while the engine is running ......... 11 -4
Engine hood ....................................... ................ 11-4
Engine compartment overview ....................... .. 11-6
Non-turbo models .................................. ................. 11-6
Turbo models ...................................... .................... 11-7
Engine oil ........................................ .................... 11-8
Checking the oil level ............................ ................. 11-8
Changing the oil and oil filter ................... ............. 11-8
Recommended grade and viscosity ................... .. 11-10
Recommended grade and viscosity under severe driving conditions ......................... ........... 11-11
Synthetic oil ..................................... ....................... 11-11
Cooling system .................................... .............. 11-12
Cooling fan, hose and connections ................. ..... 11-12
Engine coolant .................................... .................... 11-12
Air cleaner element ............................... ............. 11-15
Replacing the air cleaner element ................. ........ 11-15
Spark plugs ....................................... .................. 11-17
Recommended spark plugs ........................... ........ 11-17
Drive belts ....................................... .................... 11-18
Manual transmission oil ........................... ......... 11-18
Checking the oil level ............................ ................. 11-18
Recommended grade and viscosity ................... .. 11-19Automatic transmission fluid ......................
...... 11-20
Checking the fluid level .......................... ................ 11-20
Recommended fluid ................................. .............. 11-21
Front differential gear oil (AT vehicles) ......... ... 11-21
Checking the oil level ............................ ................. 11-21
Recommended grade and viscosity ................... .. 11-22
Rear differential gear oil ........................ ............ 11-22
Checking the gear oil level ....................... ............. 11-22
Recommended grade and viscosity ................... .. 11-23
Power steering fluid .............................. ............. 11-24
Checking the fluid level .......................... ................ 11-24
Recommended fluid ................................. .............. 11-24
Brake fluid ....................................... .................... 11-25
Checking the fluid level .......................... ................ 11-25
Recommended brake fluid ........................... .......... 11-25
Clutch fluid (MT vehicles) ........................ .......... 11-26
Checking the fluid level .......................... ................ 11-26
Recommended clutch fluid .......................... .......... 11-26
Brake booster ..................................... ................ 11-27
Brake pedal ....................................... .................. 11-27
Checking the brake pedal free play ................ ...... 11-27
Checking the brake pedal reserve distance ......... 11-27
Clutch pedal (MT vehicles) ........................ ........ 11-28
Checking the clutch function ...................... .......... 11-28
Checking the clutch pedal free play ............... ...... 11-28
Replacement of brake pad and lining ............... 11-28
Breaking-in of new brake pads and linings ......... . 11-29
Parking brake stroke .............................. ............ 11-29

11-6 Maintenance and service
Engine compartment overview
Non-turbo models
1 2 3 4 5 6
7
8
9
10
11
13 12
B00464
1) Air cleaner element (page 11-15)
2) Manual transmission oil level gauge
(MT) (page 11-18) or Differential gear
oil level gauge (AT) (page 11-21)
3) Clutch fluid reservoir (page 11-26)
4) Automatic transmission fluid level gauge (page 11-20)
5) Brake fluid reservoir (page 11-25)
6) Fuse box (page 11-41)
7) Battery (page 11-40)
8) Windshield washer tank (page 11-36)
9) Engine coolant reservoir (page 11-
12)
10) Engine oil level gauge (page 11-8)
11) Engine oil filler cap (page 11-8)
12) Radiator cap (page 11-12)
13) Power steering fluid reservoir (page
11-24)