2003 GMC SIERRA ECU

{CAUTION:
Things you put inside your vehicle can strike
and injure people in a sudden stop or turn, or
in a crash.
Put things in the trunk of your vehicle. In a
trunk, put them as far forward as you can.
Try to spread the weight evenly.
Never stack heavier things, like suitcases,
inside the vehicle so that some of them
are above the tops of the seats.
Don’t leave an unsecured child restraint in
your vehicle.
When you carry something inside the
vehicle, secure it whenever you can.
There’s also important loading information for off-road
driving in this manual. See“Loading Your Vehicle
for Off-Road Driving“underOperating Your
All-Wheel-Drive Vehicle Off Paved Roads on page 4-18.
Payload
Payload capacity is the maximum load capacity that
your vehicle can carry. Be sure to include the weight of
the occupants as part of your load. If you added any
accessories or equipment after your vehicle leftthe factory, remember to subtract the weight of these
things from the payload. Your dealer can help you
with this.
Remember not to exceed the Gross Axle Weight Rating
(GAWR) of the front or rear axle.
Two-Tiered Loading
By positioning four 2”x6”wooden planks across the
width of the pickup box, you can create an upper
load platform. The planks must be inserted in the pickup
box depressions. The length of the planks must allow
for at least a 3/4 inch (2 cm) bearing surface on
each end of the plank.
When using this upper load platform, be sure the load is
securely tied down to prevent it from shifting. The
load’s center of gravity should be positioned in a zone
over the rear axle. The zone is located in the area
between the front of each wheel well and the rear of
each wheel well. The center of gravity height must not
extend above the top of the pickup boxareboard.
Any load that extends beyond the vehicle’s taillamp area
must be properly marked according to local laws and
regulations.
Remember not to exceed the Gross Axle Weight Rating
(GAWR) of the front or rear axle.
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Your dealer can help you make a good vehicle-camper
match. He’ll also help you determine your CWR.
After you’ve loaded your vehicle and camper, drive to a
weigh station and weigh the front and rear wheels
separately. This will tell you the loads on your axles.
The loads on the front and rear axles shouldn’tbemore
than either of the GAWRs. The total of the axle loads
should not be more than the GVWR.
Open your driver’s door and look at the Certication/Tire
label tond out your GAWR and GVWR.
If you’ve gone over your weight ratings, move or take
out some things until all the weight falls below the
ratings. Of course, you should always tie down any
loose items when you load your vehicle or camper.
When you install and load your slide-in camper, check
the manufacturer’s instructions.
If you want more information on curb weights, cargo
weights, Cargo Weight Rating and the correct center of
gravity zone for your vehicle, your dealer can help
you. Just ask for a copy of″Consumer Information,
Truck-Camper Loading.″Trailer Recommendations
You must subtract your hitch loads from the CWR for
your vehicle. Weigh your vehicle with the trailer
attached, so that you won’t go over the GVWR or
GAWR. If you are using a weight-distributing hitch,
weigh the vehicle without the spring bars in place.
You’ll get the best performance if you spread out the
weight of your load the right way, and if you choose the
correct hitch and trailer brakes.
For more information, see″Trailer Towing″in the Index.
Pickup Conversion to
Chassis Cab
General Motors is aware that some vehicle owners may
consider having the pickup box removed and a
commercial or recreational body installed. Before you do
so,rst contact GM Customer Assistance for information
on such conversions specic to this vehicle. Owners
should be aware that, as manufactured, there are
differences between a chassis cab and a pickup with
the box removed which may affect vehicle safety.
The components necessary to adapt a pickup to permit
its safe use with a specialized body should be
installed by a body builder in accordance with the
information available from GM Customer Assistance.
SeeCustomer Assistance Offices on page 7-4.
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Driving with a Trailer
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 the trailer hitch and platform
(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.
While towing a trailer or when exposed to long periods
of sunshine, theoor of the truck bed may become
very warm. Avoid putting items in the truck bed
that might be affected by high ambient temperatures.
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.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a good deal
longer, you’ll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Your vehicle is equipped with four-wheel steering and if
you use it while backing your trailer the same rules
apply. However, with four-wheel steering your rig will
respond more quickly and it may take additional practice
to get used to backing up with four-wheel steering.
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Tire Inspection and Rotation
Tires should be rotated every 7,500 miles (12,500 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 5-59andWheel Replacement
on page 5-62for 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 and jack handle extensions to
tighten the cable. SeeChanging a Flat Tire on
page 5-65.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. Thefirst rotation
is the most important. See“Part A: Scheduled
Maintenance Services,”in Section 6, for scheduled
rotation intervals.When rotating your tires, always use the correct rotation
pattern shown here.
Don’t include the spare tire in your tire rotation.
After the tires have been rotated, adjust the front and
rear inflation pressures as shown on the
Certification/Tire label. Make certain that all wheel nuts
are properly tightened. See“Wheel Nut Torque”
underCapacities and Specifications on page 5-99.
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Storing a Flat or Spare Tire, Jack
and Tools
{CAUTION:
Storing a jack, a tire, or other equipment in the
passenger compartment of the vehicle could
cause injury. In a sudden stop or collision,
loose equipment could strike someone. Store
all these in the proper place.
Notice:An aluminum wheel with aflat tire should
always be stored under the vehicle with the
hoist. However, storing it that way for an extended
period of time could damage the wheel. To avoid
this, always stow the wheel properly with the valve
stem pointing down and have the wheel repaired
as soon as possible.
Return the bottle jack, wheel blocks, wheel wrench and
jack extensions to their location under the passenger’s
side second row seat. Secure the items in the vehicle as
shown.A. Wing Nut
B. Wheel Blocks
C. Wheel Wrench and Extensions Retainer
D. Gloves
E. Wheel Wrench and Extensions
F. Storage Bag
G. Bottle Jack Holder
H. Bottle Jack
I. Wheel Block Retainer
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A. Push and Pull
B. Rotate Tire
7. Make sure the tire is stored securely. Push, pull,
and then try to rotate or turn the tire. If the tire
moves, use the wheel wrench to tighten the cable.
Reinstall the spare tire lock (if equipped).
Secondary Latch System
Your vehicle has an underbody mounted tire hoist
assembly equipped with a secondary latch system.
It’s designed to stop the spare tire from suddenly falling
off your vehicle. For the secondary latch to work, the
spare must be installed with the valve stem pointing
down. See“Storing a Flat or Spare Tire, Jack and Tools”
earlier in this section.
{CAUTION:
Before beginning this procedure read all the
instructions. Failure to read and follow the
instructions could damage the hoist assembly
and you and others could get hurt. Read and
follow the instructions listed below.
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To release the spare tire from the secondary latch do
the following:
1. Check under the vehicle to see if the cable end is
visible.
2. If the cable is not visible proceed to Step 6.
If it is visible,first try to tighten the cable by turning
the wheel wrench clockwise until you hear two
clicks or feel it skip twice. You cannot overtighten
the cable.
3. Loosen the cable by turning the wrench
counterclockwise three or four turns.4. Repeat this procedure at least two times. If the
spare tire lowers to the ground, continue with
Step 5 of“Removing the Spare Tire and Tools”
earlier in this section.
5. Turn the wrench counterclockwise until
approximately six inches (15 cm) of cable is
exposed.
6. Stand the wheel blocks
on their shortest ends,
with the backs
facing each other.
7. Place the bottom edge of the jack on the wheel
blocks, separating them so that the jack is
balanced securely.
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Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
Wiper Blade Check
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield. Also see
Cleaning the Outside of Your Vehicle on page 5-85.
Spare Tire Check
At least twice a year, after the monthly ination check of
the spare tire determines that the spare is inated to
the correct tire ination pressure, make sure that
the spare tire is stored securely. Push, pull, and then try
to rotate or turn the tire. If it moves, use the wheel
wrench/ratchet to tighten the cable. SeeChanging a Flat
Tire on page 5-65.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be
required. SeePart D: Recommended Fluids and
Lubricants on page 6-15.
Automatic Transmission Check
Check the transmissionuid level; add if needed. See
Automatic Transmission Fluid on page 5-20.Auid loss
may indicate a problem. Check the system and repair
if needed.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specied in Part D.
Body Lubrication Service
Lubricate all body door hinges, hood latch assembly,
secondary latch, pivots, spring anchor, release
pawl, tailgate hinge, tailgate linkage, tailgate handle
pivot points, latch bolt, fuel door hinge, locks and folding
seat hardware. Part D tells you what to use. More
frequent lubrication may be required when exposed to a
corrosive environment.
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