check engine SUBARU IMPREZA WRX 2003 2.G Owner's Manual

Driving tips
8-27
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Trailer towing
Your car is designed and intended to be used pri-
marily as a passenger-carrying vehicle. Towing a
trailer puts additional loads on your car ’s engine, dri-
vetrain, brakes, tires and suspension and has an
adverse effect on fuel economy.
If you do decide to tow a trailer, your safety and sat-
isfaction depend upon proper use of correct equip-
ment and cautious operation of your vehicle. Seekthe advice of your SUBARU dealer to assist you in
purchasing a hitch and other necessary towing
equipment appropriate for your vehicle. In addition,
be sure to follow the instructions on correct installa-
tion and use provided by the trailer and other towing
equipment manufacturers.
SUBARU assumes no responsibility for injuries or
vehicle damage that result from trailer towing equip-
ment, or from any errors or omissions in the instruc- tions accompanying such equipment or for your fail-
ure to follow the proper instructions. Warranties and maintenance
SUBARU warranties do not apply to vehicle damage or malfunction caused by trailer towing. If you use
your vehicle to tow a trailer, more frequent mainte-
nance will be required due to the additional load. (Refer to
“Maintenance schedule under severe driv-
ing conditions ” in the “Warranty and Maintenance
Booklet”.)
Under no circumstances should a trailer be towedwith a new vehicle or a vehicle with any new power-
train component (engine, transmission, differential, wheel bearings, etc.) for the first 1,000 miles (1,600 km) of driving. Maximum load limits
WARNING
Never exceed the maximum load limits ex-
plained below. Exceeding the maximum loadlimits could cause personal injury and/or ve-hicle damage.
CAUTION
Adequate size trailer brakes are required
when the trailer and its cargo exceed 1,000 lbs (453 kg) total weight. Before towing a trailer, check the trailer total
weight, GVW, GAWs and tongue load. Make sure the load and its distribution in your
vehicle and trailer are acceptable.

Driving tips
8-36
safety’s sake, you should employ extra cau-
tion when towing a trailer and you should
never speed. You should also keep the follow-ing tips in mind:
Before starting out on a trip
Check that the vehicle and vehicle-to-hitch mount-
ing are in good condition. If any problems are
apparent, do not tow the trailer. Check that the vehicle sits horizontally with the
trailer attached. If the vehicle is tipped sharply up at
the front and down at the rear, check the total trailer
weight, GVW, GAWs and tongue load again, then
confirm that the load and its distribution are accept-able. Check that the tire pressures are correct.
Check that the vehicle and trailer are connected
properly. Confirm that
–the trailer tongue is connected properly to the
hitch ball.– the trailer lights connector is connected prop-
erly and trailer ’s brake lights illuminate when the
vehicle’ s brake pedal is pressed, and that the trail-
er’ s turn signal lights flash when the vehicle ’s turn
signal lever is operated.– the safety chains are connected properly. –
all cargo in the trailer is secured safety in posi-
tion.– the side mirrors provide a good rearward field of
view without a significant blind spot.
Sufficient time should be taken to learn the “feel”
of the vehicle/trailer combination before starting out
on a trip. In an area free of traffic, practice turning, stopping and backing up.
Driving with a trailer
You should allow for considerably more stopping
distance when towing a trailer. Avoid sudden brak-
ing because it may result in skidding or jackknifing
and loss of control. Avoid abrupt starts and sudden accelerations. If
your vehicle has a manual transmission, always start
out in first gear and release the clutch at moderate
engine revolution. Avoid uneven steering, sharp turns and rapid lane
changes. Slow down before turning. Make a longer than
normal turning radius because the trailer wheels will
be closer than the vehicle wheels to the inside of the
turn. In a tight turn, the trailer could hit your vehicle. Crosswinds will adversely affect the handling of
your vehicle and trailer, causing sway. Crosswindscan be due to weather conditions or the passing of

In case of emergency
9-18
Confirm that the cooling fan is turning. If the fan is
not turning, immediately turn the engine off and con-
tact your authorized dealer for repair.
3. After the engine coolant temperature has
dropped, turn off the engine.
If the temperature gauge stays at the overheated
zone, turn the engine off.
4. After the engine has fully cooled down, check the
coolant level in the reserve tank.If the coolant level is below the “LOW” mark, add
coolant up to the “FULL” mark.
5. If there is no coolant in the reserve tank, add
coolant to the reserve tank. Then remove the radia- tor cap and fill the radiator with coolant.
If you remove the radiator cap from a hot radiator,
first wrap a thick cloth around the radiator cap, then
turn the cap counterclockwise slowly without press-
ing down until it stops. Release the pressure from
the radiator. After the pressure has been fully re-
leased, remove the cap by pressing down and turn-ing it. Towing
If towing is necessary, it is best done by your
SUBARU dealer or a commercial towing service.
Observe the following procedures for safety.
WARNING
Never tow AWD vehicles (both AT and MT) with the front wheels raised off the groundwhile the rear wheels are on the ground, orwith the rear wheels raised off the groundwhile the front wheels are on the ground. This

11
11-1
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Maintenance schedule 11-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance precautions 11-3 . . . . . . . . . . . . . . . . . . . . . . . .
Engine hood 11-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine compartment overview 11-8 . . . . . . . . . . . . . . . . .
2.5 liter model 11-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.0 liter (Turbo) model 11-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil 11-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the oil level 11-10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the oil and oil filter 11-11 . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-13 . . . . . . . . . . .
Recommended grade and viscosity under
severe driving conditions 11-15 . . . . . . . . . . . . . . . . . . . . . .
Synthetic oil 11-15
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling system 11-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling fan, hose and connections 11-16 . . . . . . . . . . . .
Engine coolant 11-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air cleaner element 11-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the air cleaner element 11-20 . . . . . . . . . . . . . .
Spark plugs 11-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended spark plugs 11-24 . . . . . . . . . . . . . . . . . . . . .
Drive belts 11-24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual transmission oil 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the oil level 11-25 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-26 . . . . . . . . . . .
Automatic transmission fluid 11-27 . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-27 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Front differential gear oil (AT vehicles) 11-29
. . . . .
Checking the oil level 11-29 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-30 . . . . . . . . . . .
Rear differential gear oil 11-31 . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the gear oil level 11-31 . . . . . . . . . . . . . . . . . . . . . . .
Recommended grade and viscosity 11-32 . . . . . . . . . . .
Power steering fluid 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-32 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended fluid 11-33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-34 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended brake fluid 11-34 . . . . . . . . . . . . . . . . . . . . . . .
Clutch fluid (MT vehicles) 11-35 . . . . . . . . . . . . . . . . . . . . . . . .
Checking the fluid level 11-35 . . . . . . . . . . . . . . . . . . . . . . . . . .
Recommended clutch fluid 11-36 . . . . . . . . . . . . . . . . . . . . . .
Brake booster 11-36 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake pedal 11-37 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking the brake pedal free play 11-37 . . . . . . . . . . . .
Checking the brake pedal reserve distance 11-37 . .
Clutch pedal (MT vehicles) 11-38 . . . . . . . . . . . . . . . . . . . . . .
Checking the clutch function 11-38 . . . . . . . . . . . . . . . . . . . .
Checking the clutch pedal free play 11-38 . . . . . . . . . . .
Replacement of brake pad and lining 11-39 . . . . . . . .
Breaking-in of new brake pads and linings 11-39 . . .
Parking brake stroke 11-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tires and wheels 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Types of tires 11-41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance and service

Maintenance and service
11-4
Always be very careful to avoid injury when
working on the vehicle. Remember that some of the materials in the vehicle may be hazard-
ous if improperly used or handled, for exam-ple, battery acid. Your vehicle should only be serviced by per-
sons fully competent to do so. Serious per-sonal injury may result to persons not experi-enced in servicing vehicles. Always use the proper tools and make cer-
tain that they are well maintained. Never get under the vehicle supported only
by a jack. Always use a safety stands to sup-port the vehicle. 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 per-
formed only by your SUBARU dealer. Wear adequate eye protection to guard
against getting oil or fluids in your eyes. If something does get in your eyes, thoroughly
wash them out with clean water. Do not tamper with the wiring of the SRS airbag system or seatbelt pretensioner sys-tem, or attempt to take its connectors apart,as that may activate the system or it can ren-der it inoperative. The wiring and connectorsof these systems are yellow for easy identifi-cation. NEVER use a circuit tester for these wiring. If your SRS airbag or seatbelt pretensionerneeds service, consult your nearest SUBARU
dealer.
Before checking or servicing in the
engine compartment
Always stop the engine and set the parking
brake firmly to prevent the vehicle from mov- ing. Always let the engine cool down. Engine
parts become very hot when the engine is run-
ning and remain hot for some time after theengine is stopped. Do not spill engine oil, engine coolant, brake
fluid or any other fluid on hot engine compo-nents. This may cause a fire. Always remove the key from the ignition
switch. When the ignition switch is in the
“ON” position, the cooling fan may operate

Maintenance and service
11-5
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suddenly even when the engine is stopped. When you do checking or servicing in the engine compartment whilethe engine is running
A running engine can be dangerous. Keep your fingers, hands, clothing, hair and toolsaway from the cooling fan, belts and any other
moving engine parts. Removing rings,watches and ties is advisable. Engine hood
To open the hood:
1. Pull the hood release knob under the instrument panel.

Maintenance and service
11-10
Engine oil Checking the oil level
Check the engine oil level at each fuel stop.
1. Park the vehicle on a level surface and stop theengine.
2. Pull out the dipstick, wipe it clean, and insert it again.
3. Be sure the dipstick is correctly inserted until it
stops with the graphic symbol i on its top ap-
pearing as shown in the illustration.
1) Notch
2) Upper level 3) Lower level
4) Front of vehicle
4. Pull out the dipstick again and check the oil level on it. If it is below the lower level, add oil to bring thelevel up to the upper level.
CAUTION
Use only engine oil with the recommended
grade and viscosity. Be careful not to spill engine oil when ad-
ding it. If oil touches the exhaust pipe, it may
cause a bad smell, smoke, and/or a fire.

Maintenance and service
11-11
– CONTINUED –
If you check the oil level just after stopping the en-
gine, wait a few minutes for the oil to drain back into
the oil pan before checking the level.
Just after driving or while the engine is warm, the
engine oil level reading may be in a range betweenthe upper level and the notch mark. This is caused
by thermal expansion of the engine oil.
To prevent overfilling the engine oil, do not add any
additional oil above the upper level when the engineis cold. Changing the oil and oil filter
Change the oil and oil filter according to the mainte-
nance schedule in the “Warranty and Maintenance
Booklet”.
The engine oil and oil filter must be changed more
frequently than listed in the maintenance schedule
when driving on dusty roads, when short trips are
frequently made, or when driving in extremely cold
whether.
1. Warm up the engine by letting the engine idle for
about 10 minutes to ease draining the engine oil.
2. Park the vehicle on a level surface and stop theengine.
3. Remove the oil filler cap.
1) Drain plug
4. Drain out the engine oil by removing the drain
plug while the engine is still warm. The used oil
should be drained into an appropriate container and
disposed of properly.
WARNING
Be careful not to burn yourself with hot en- gine oil.
5. Wipe the seating surface of the drain plug with a
clean cloth and tighten it securely with a new seal-

Maintenance and service
11-12
ing washer after the oil has completely drained out.
1) Oil filter
6. Remove the oil filter with an oil filter wrench.
7. Before installing a new oil filter, apply a thin coatof engine oil to the seal.
8. Clean the rubber seal seating area of the lower
crank case and install the oil filter by hand turning.
Be careful not to twist or damage the seal.
9. Tighten it approximately two-thirds of a turn after the seal makes contact with the lower crank case.
CAUTION
Never over tighten the oil filter because that can result in an oil leak.
10. Pour engine oil through the filler neck.
Oil capacity (guideline): Non-turbo models: 4.2 US qt (4.0 liters, 3.5 Imp qt)
Turbo models: 4.8 US qt (4.5 liters, 4.0 Imp qt)
The oil quantity indicated above is only guideline.
The necessary quantity of oil depends on the quan- tity of oil that has been drained. The quantity of
drained oil differs slightly depending on the temper-
ature of the oil and the time the oil is left flowing out.
After refilling the engine with oil, therefore, you must
the dipstick to confirm that the level is correct.
11. Start the engine and make sure that no oil leaks
appear around the filter ’s rubber seal and drain
plug.
12. Run the engine until it reaches the normal oper-
ating 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 engine oil.

Maintenance and service
11-16
Do not splash the engine coolant over
painted parts. The alcohol contained in the en- gine coolant may damage the paint surface.
Cooling fan, hose and connections
Your vehicle employs an electric cooling fan which
is thermostatically controlled to operate when the
engine coolant reaches a specific temperature.If the radiator cooling fan does not operate even
when the engine coolant temperature gauge ex-
ceeds the normal operating range, the cooling fan
circuit may be defective. Check the fuse and re-
place it if necessary. If the fuse is not blown, havethe cooling system checked by your SUBARU deal-
er.
If frequent addition of coolant is necessary, there
may be a leak in the engine cooling system. It is rec-
ommended that the cooling system and connectionsbe checked for leaks, damage, or looseness.
Engine coolant
Checking the coolant level
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 res-ervoir 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.