2004 CHEVROLET BLAZER ECU

Driving with a Trailer
{CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon
monoxide (CO) could come into your vehicle.
You can not see or smell CO. It can cause
unconsciousness or death. SeeEngine
Exhaust on page 2-40. To maximize your safety
when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle. Do not use
the climate control setting for maximum air
because it only recirculates the air inside
your vehicle. See Climate Control System
in the Index.Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch, parts and
attachments, safety chains, electrical connector, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
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Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission uid (don’t overll),
engine oil, axle lubricant, belt, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd them quickly. If
you’re trailering, it’s a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The light-duty trailer wiring is a six-wire harness
assembly. The optional heavy-duty trailer wiring is an
eight-wire harness assembly. The harnesses are stored
under the vehicle, along the passenger-side frame
crossmember on two-door vehicles or on the driver’s
side corner frame rear crossmember on four-door
vehicles. The heavy-duty trailer wiring is fused in the
engine compartment fuse block. SeeFuses and Circuit
Breakers on page 5-99. Both harnesses have no
connector and should be wired by a qualied electrical
technician.The technician can use the following color code chart
when connecting the wiring harness to your trailer.
Dark Blue: Use for electric trailer brakes or auxiliary
wiring (eight-wire harness only).
Red: Use for battery charging; it connects to the
starter solenoid (eight-wire harness only).
Light Green: Back-up lamps.
Brown: Taillamps and parking lamps.
Yellow: Driver’s side stoplamp and turn signal.
Dark Green: Passenger’s side stoplamp and turn
signal.
White: Ground wire.
Light Blue: Auxiliary stoplamp.
Securely attach the harness to the trailer, then tape or
strap it to your vehicle’s frame rail. Be sure you
leave it loose enough so the wiring doesn’t bend or
break, but not so loose that it drags on the ground. Store
the harness in its original place. Wrap the harness
together and tie it neatly so it won’t be damaged.
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Remote Oil Filter (Four-Wheel Drive)
The access door for the
remote oil lter is in the
steering linkage shield
assembly located under
the radiator support.
Turn the screw to unlock
or lock the door. If you
open the door, make sure
it is securely closed
when you are nished.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
lter before disposal. Never dispose of oil by putting it in
the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by taking it
to a place that collects used oil. If you have a problem
properly disposing of your used oil, ask your dealer, a
service station or a local recycling center for help.
Engine Air Cleaner/Filter
SeeEngine Compartment Overview on page 5-12
for more information on the location of the engine
air cleaner/lter.
5-17

The vehicle must be on a level surface. When your
engine is cold, the coolant level should be at ADD,
or a little higher. When your engine is warm, the level
should be up to FULL HOT, or a little higher.
Adding Coolant
If you need more coolant, add the proper DEX-COOL®
coolant mixtureat the coolant recovery tank.
{CAUTION:
Turning the radiator pressure cap when the
engine and radiator are hot can allow steam and
scalding liquids to blow out and burn you badly.
With the coolant recovery tank, you will almost
never have to add coolant at the radiator.
Never turn the radiator pressure cap — even a
little — when the engine and radiator are hot.Add coolant mixture at the recovery tank, but be careful
not to spill it.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol,
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
Occasionally check the coolant level in the radiator.
For information on how to add coolant to the radiator,
seeCooling System on page 5-29.
Radiator Pressure Cap
Notice:If the pressure cap is not tightly installed,
coolant loss and possible engine damage may occur.
Be sure the cap is properly and tightly secured.
5-26

When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire.
If you have a compact spare tire, it should be
at 60 psi (420 kPa).
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell if your tires are properly inated
simply by looking at them. Radial tires may look properly
inated even when they’re underinated. Check the tire’s
ination pressure when the tires are cold. cold means
your vehicle has been sitting for at least three hours or
driven no more than 1 mile (1.6 km).
remove the valve cap from the tire valve stem. Press
the tire gage rmly onto the valve to get a pressure
measurement. If the cold tire ination pressure matches
the recommended pressure on the tire and loading
information label, no further adjustment is necessary.
If the pressure is low, add air until you reach the
recommended amount.
If you overll the tire, release air by pushing on the
metal stem in the center of the tire valve. Recheck the
tire pressure with the tire gage.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and moisture.
Tire Inspection and Rotation
Tires should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km).
Any time you notice unusual wear, rotate your tires as
soon as possible and check wheel alignment. Also
check for damaged tires or wheels. SeeWhen It Is Time
for New Tires on page 5-70andWheel Replacement
on page 5-73for more information.
Make sure the spare tire is stored securely. Push, pull,
and then try to rotate or turn the tire. If it moves,
use the wheel wrench to tighten the cable. See
Changing a Flat Tire on page 5-76.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The rst rotation
is the most important. SeePart A: Scheduled
Maintenance Services on page 6-4, for scheduled
rotation intervals.
5-68

4. Raise the tire fully against the underside of the
vehicle by turning the wrench clockwise until you
hear two clicks or feel it skip twice. The spare
tire hoist cannot be overtightened.
5. Make sure the tire is stored securely. Push, pull (A),
and then try to rotate or turn (B) the tire. If the tire
moves, use the wheel wrench to tighten the cable.Follow this diagram for the inside-mounted spare.
A. Spare or Flat Tire
B. Retainer
C. NutD. Wheel Carrier
E. Hook
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Follow this diagram for the rear-mounted spare.
A. Wheel Carrier
B. Spare or Flat TireC. Wheel Nut and Locking
Nut Cylinder (If Equipped)6. Reinstall the locking wheel nut using the wheel
wrench. Then push the lock case onto the lug
nut until it stops. The key does not have to
be inserted into the lock. Push the lock case to be
sure it is secured. The special lug nut and lock
case is not intended to be used on any road wheel,
only on the spare wheel carrier. Tighten the nuts
on the wheel carrier to 22 to 32 lb-ft (30 to 40 N·m).
{CAUTION:
Make sure the tire and carrier are secure.
Driving with the tire or carrier unlatched could
injure pedestrians or damage the vehicle.
5-87

7. Return the jack, wheel wrench and wheel blocks to
the proper location in your vehicle’s rear area.
Secure the items and replace the jack cover.
Use the following diagram as a guide.
A. Retainer
B. Rubber Band
(Some Models)
C. Jack Storage Cover
D. Wheel Blocks
E. Hub Cap Removal
Tool (Some Models)F. Wheel Wrench
G. Jack
H. Jacking Instructions (roll
and place instructions
above the jack after it is
installed)Compact Spare Tire
The compact spare tire is a temporary replacement tire
made to perform at speeds up to 65 mph (105 km/h)
and for distances up to 3,000 miles (5 000 km). With the
compact spare installed, you can nish your trip and
then have the damaged or at road tire repaired
or replaced. Of course, it’s best to repair or replace the
damaged road tire as soon as you can. Your compact
spare tire will last longer and be in good shape in case
you need it again.
The compact spare may lose air after a time, so check
the ination pressure regularly. After installing the
compact spare on your vehicle, stop as soon as possible
and make sure it’s correctly inated. It should be
60 psi (420 kPa).
Don’t use your compact spare tire on other vehicles and
don’t mix your compact spare tire or wheel with other
wheels or tires, they won’t t. Keep your compact spare
and its wheel together. Don’t include the compact
spare in your tire rotation.
Notice:When the compact spare is installed, don’t
take your vehicle through an automatic car wash
with guide rails. The compact spare can get caught
on the rails. That can damage the tire and wheel,
and maybe other parts of your vehicle.
5-88