2004 SUBARU IMPREZA WRX check engine

7-30
Starting and operating
ABS (Anti-lock Brake System)
The ABS system prevents the lock-up of wheels which
may occur during sudden braking or braking on slip-
pery road surfaces. 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).
Always use the utmost care in driving – over-
confidence because you are driving with an
ABS equipped vehicle could easily lead to a se-
rious accident.
"
The ABS system does not always decrease
stopping distance. You should always main-
tain a safe following distance from other vehi- cles. "
When driving on badly surfaced roads, gravel
roads, icy roads, or over deep newly fallen
snow, stopping distances may be longer for a
vehicle with the ABS system than one without.
When driving under these conditions, there-
fore, reduce your speed and leave ample dis-
tance from other vehicles. " When you feel the ABS system operating,
you should maintain constant brake pedal pres-
sure. Do not pump the brake pedal since doing
so may defeat the operation of the ABS system.
! ABS system self-check
You may feel a slight shock in the brake pedal and hear the operating sound of ABS from the engine com-
partment just after the vehicle is started. This is
caused by an automatic functional test of the ABS sys-
tem being carried out and does not indicate any abnor-
mal condition.

7-33
Starting and operating
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!Steps to take if EBD system fails
If a malfunction occurs in the EBD system, the system
stops working and the brake system warning light and
ABS warning light come on simultaneously.
The EBD system may be faulty if the brake system
warning light and ABS warning light illuminate simulta-
neously during driving.
Even if the EBD system fails, the conventional braking
system will still function. However, the rear wheels will
be more prone to locking when the brakes are applied
harder than usual and the vehicle’s motion may there-
fore 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 place.
2. Shut down the engine, then restart it.
3. Release the parking brake. If both warning lights go
out, the EBD system may be faulty. Drive carefully to
the nearest SUBARU dealer and have the system in- spected.
4. If both warning lights come on again and stay illu-
minated after the engine has been restarted, shut
down the engine again, apply the parking brake, and
check the brake fluid level.
5. If the brake fluid level is not below the “MIN” mark,
the EBD system may be faulty. Drive carefully to the
nearest SUBARU dealer and have the system inspect- ed.
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.
"
Driving with the brake system warning light
on is dangerous. This indicates your brake sys-
tem may not be working properly. If the light re-
mains on, have the brakes inspected by a SUB-
ARU dealer immediately." If at all in doubt about whether the brakes are
UG7020CA

8-3
Driving tips
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Engine exhaust gas (Carbon monox-
ide)
"Never inhale engine exhaust gas. Engine ex-
haust gas contains carbon monoxide, a color-
less and odorless gas which is dangerous, or
even lethal, if inhaled. " Always properly maintain the engine exhaust
system to prevent engine exhaust gas from en-
tering the vehicle. " Never run the engine in a closed space, such
as a garage, except for the brief time needed to
drive the vehicle in or out of it. " Avoid remaining in a parked vehicle for a
lengthy time while the engine is running. If that
is unavoidable, then use the ventilation fan to
force fresh air into the vehicle." Always keep the front ventilator inlet grille
free from snow, leaves or other obstructions to
ensure that the ventilation system always
works properly." If at any time you suspect that exhaust fumes
are entering the vehicle, have the problem
checked and corrected as soon as possible. If
you must drive under these conditions, drive only with all windows fully open. "
Keep the trunk lid or rear gate closed while
driving to prevent exhaust gas from entering
the vehicle.
NOTE
Due to the expansion and contraction of the met-
als used in the manufacture of the exhaust sys-
tem, you may hear a crackling sound coming from
the exhaust system for a short time after the en-
gine has been shut off. This sound is normal.

8-5
Driving tips
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Non-turbo models
The catalytic converter is installed in the exhaust sys-
tem. It serves as catalyst to reduce HC, CO and NOx
in exhaust gases, thus providing cleaner exhaust.
To avoid damage to the catalytic converter: " Use only unleaded fuel. Even a small amount of
leaded fuel will damage the catalytic converter." Never start the engine by pushing or pulling the ve-
hicle. " Avoid racing the engine.
" Never turn off the ignition switch while the vehicle is
moving." Keep your engine tuned-up. If you feel the engine running rough (misfiring, backfiring or incomplete
combustion), have your vehicle checked and repaired
by an authorized SUBARU dealer."
Do not apply undercoating or rust prevention treat-
ment to the heat shield of catalytic converter and the
exhaust system.
" Avoid fire hazards. Do not drive or park the
vehicle anywhere near flammable materials
(e.g. grass, paper, rags or leaves), because the
catalytic converter operates at very high tem-
peratures. " Keep everyone and flammable materials
away from the exhaust pipe while the engine is
running. The exhaust gas is very hot.
HS8002BA

8-7
Driving tips
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Driving tips for AWD vehicles
All wheel drive distributes the engine power to all four
wheels. AWD vehicles provide better traction when
driving on slippery, wet or snow-covered roads and
when moving out of mud, dirt and sand. By shifting
power between the front and rear wheels, SUBARU
AWD can also provide added traction during acceler-
ation and added engine braking force during deceler-
ation.
Therefore, your SUBARU AWD vehicle may handle
differently than an ordinary two wheel drive vehicle
and it contains some features unique to AWD. For safety purposes as well as to avoid damaging the
AWD system, you should keep the following tips in mind: "
An AWD vehicle is better able to climb steeper
roads under snowy or slippery conditions than a two
wheel drive vehicle. There is little difference in han-
dling, however, during extremely sharp turns or sud-
den braking. Therefore, when driving down a slope or
turning corners, be sure to reduce your speed and
maintain an ample distance from other vehicles." When replacing a tire, make sure you use only the
same size, construction, brand, and load range as the
original tires listed on the tire placard. Using other siz-
es, circumference or construction may result in severe
mechanical damage to the drive train of your vehicle
and may affect ride, handling, braking, speedometer/
odometer calibration, and clearance between the body
and tires. It also may be dangerous and lead to loss of
vehicle control." If you use a temporary spare tire to replace a flat
tire, be sure to use the original temporary spare tire
stored in the vehicle. Using other sizes may result in
severe mechanical damage to the drive train of your
vehicle. " Always check the cold tire pressure before starting
to drive. The recommended tire pressure is provided
on the tire placard, which is located under the door
HS8003BA

8-10
Driving tips
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 com-
pletely through the stream. The water should be shal-
low enough that it does not reach the vehicle’s under-
carriage. Water entering the engine air intake or the
exhaust pipe or water splashing onto electrical parts
may damage your vehicle and may cause it to stall.
Never attempt to drive through rushing water; regard-
less of its depth, it can wash away the ground from un-
der your tires, resulting in possible loss of traction and
even vehicle rollover. "
Always check your brakes for effectiveness immedi-
ately after driving in sand, mud or water. Do this by
driving slowly and stepping on the brake pedal. Re-
peat that process several times to dry out the brake
discs and brake pads. " Do not drive or park over or near flammable materi-
als such as dry grass or fallen leaves, as they may
burn easily. The exhaust system is very hot while the
engine 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 under-
body. 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 vehicle 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 injury. 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 accelerator pedal slightly and move
the selector lever back and forth between “D” and “R”
repeatedly. Do not race the engine. For the best pos-
sible traction, avoid spinning the wheels when trying to
free the vehicle.
When the road surface is extremely slippery, 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 larger than those
specified in this manual. " Frequent driving of an AWD vehicle under hard-driv-
ing conditions such as rough roads or off roads will ne-
cessitate more frequent replacement of engine oil,
brake fluid and transmission oil than that specified in
the maintenance schedule described in the “Warranty
and Maintenance Booklet”.
Remember that damage done to your Subaru while

8-11
Driving tips
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operating it off-road and not using common sense pre-
cautions such as those listed above is not eligible for
warranty 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.Winter driving ! Operation during cold weather
Carry some emergency equipment, such as tire
chains, a window scraper, a bag of sand, flares, a
small shovel, and jumper cables.
Check the battery and cables. Cold temperatures re-
duce battery capacity. The battery must be in good
condition to provide enough power for cold winter starts.
Use an engine oil of proper grade and viscosity for
cold weather. Heavy summer oil will cause harder
UG8030AA

8-12
Driving tips
starting.
Keep the door locks from freezing by squirting them
with deicer or glycerin.
Forcing a frozen door open may damage or separate
the rubber weather strips around the door. If the door
is frozen, use hot water to melt the ice, and afterwards
thoroughly wipe the water away.
Use a windshield washer fluid that contains an anti-
freeze solution. Do not use engine antifreeze or other
substitutes because they may damage the paint of the
vehicle. !
Before driving your vehicle
Before entering the vehicle, remove any snow or ice
from your shoes because that could make the pedals
slippery and dangerous.
While warming up the vehicle before driving, check
that the accelerator pedal, brake pedal, and all other
controls operate smoothly.
Clear away ice and snow that has accumulated under
the fenders to avoid making steering difficult. During
severe winter driving, stop when and where it is safe
to do so and check under the fenders periodically. !
Parking in cold weather
Do not use the parking brake when parking for long
periods in cold weather since it could freeze in that po-
sition. Instead, observe the following:
1. Place the shift lever in “1” or “R” for manual trans-
mission vehicles, and in “P” for automatic transmission
vehicles.
2. Use tire stops under the tires to prevent the vehicle
from moving.
When the vehicle is parked in snow or when it snows,
raise the wiper blades off the glass to prevent damageto them.
When the vehicle has been left parked after use on
roads heavily covered with snow, or has been left
parked during a snowstorm, icing may develop on the
brake system, which could cause poor braking action.
Check for snow or ice buildup on the suspension, disc
brakes and brake hoses underneath the vehicle.
If there is caked snow or ice, remove it, being careful
not to damage the disc brakes and brake hoses andABS harness.
Snow can trap dangerous exhaust gases under
your vehicle. Keep snow clear of the exhaust