1997 GMC SIERRA ECU

Before You Go Off-Roading
There are some things to do before you go out. For
example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields
(if so equipped) are properly
attached. Be sure you
read all the information about
your four-wheel-drive vehicle in this manual.
Is there
enough fuel?
Is the spare tire fully inflated? Are the
fluid levels up where they should be? What are the local
laws that apply to off-roading where you’ll be driving?
If you don’t know, you should check
with law
enforcement people
in the area. Will you be on
someone’s private land?
If so, be sure to get the
necessary permission.
Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to load your vehicle.
The heaviest things should be on the load floor and
forward
of your rear axle. Put heavier items as far
forward as you can.
Be sure the load is secured properly, so driving on
the off-road terrain doesn’t toss things around.
Cargo on the load floor piled higher than
the seatbacks can be thrown forward
during a sudden stop. You or your
passengers could be injured. Keep cargo
below the top of the seatbacks.
Unsecured cargo on the load floor can be
tossed about when driving over rough
terrain. You or your passengers can
be struck
by flying objects. Secure the
cargo properly.
Heavy loads on the roof raise the vehicle’s
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured
if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the roof.
Keep cargo in the cargo area as far forward
and low
as possible.
You’ll find other important information
in this manual.
See “Vehicle Loading,” “Luggage Carrier” and “Tires”
in the Index.
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Winter Driving
Here are some tips for winter driving:
0 Have your vehicle in good shape for winter.
You may want to put winter emergency supplies in
your vehicle. Include
an ice scraper, a small brush or broom, a supply
of windshield washer fluid, a rag, some winter outer
clothing, a small shovel,
a flashlight, a red cloth and
reflective warning triangles. And, if you will be driving
under severe conditions, include a small bag of sand, a
piece of old carpet or a couple
of burlap bags to help
provide traction. Be sure you properly secure these
items in your vehicle.
Driving on Snow or Ice
Most of the time, those places where your tires meet the
road probably have good traction.
However,
if there is snow or ice between your tires and
the road, you can have a very slippery situation. You’ll
have a lot less traction or
“grip” and will need to be
very careful.
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Loading Your Vehicle
I-
GAWR FRT
RIM COLD TIRE PRESSURE
-!=2 - I
The Certificationrnire label is found on the rear edge of
the driver’s door or in the Incomplete Vehicle Document
in the cab.
The label shows the size of
your original tires and the
inflation pressures needed to obtain the gross weight
capacity
of your vehicle. This is called the GVWR
(Gross Vehicle Weight Rating). The GVWR includes the
weight
of the vehicle, all occupants, fuel and cargo.
The Certificationmire label also tells you the maximum
weights for the front and rear axles, called Gross Axle Weight Rating (GAWR). To find out the actual loads on
your front and rear axles, you need
to go to a weigh
station
and weigh your vehicle. Your dealer can help
you
with this. Be sure to spread out your load equally on
both sides of the centerline.
Never exceed the
GVWR for your vehicle, or the
GAWR for
either the front or rear axle.
And, if you do have a heavy load, you should spread
it out.
/;1 CAUTION:
In the case of a den stop or collision, things
carried in the bed of your truck could shift
forward and come into the passenger area,
injuring you and others. If you put things in the
bed
of your truck, you should make sure they are
properly secured.
Using heavier suspension components to get added
durability might not change your weight ratings. Ask
your dealer to help you load
your vehicle the right way.
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I
A CAUTION:
Do not load your vehicle any heavier than the
GVWR, or either the maximum front or rear
GAWR.
If’ you do, parts on your vehicle can
break, or
it can change the way your vehicle
handles. These could cause you to lose control.
Also, overloading can shorten the life of
your vehicle.
NOTICE:
Your warranty does not cover parts or
components that fail because of overloading.
A CAUTION:
Things you put inside your vehicle can strike
and injure people in
a sudden stop or turn,
or in a crash.
0 Put things in the cargo area of your vehicle.
Try to spread the weight evenly.
0 Never stack heavier things, like suitcases,
inside the vehicle
so that some of them are
above the tops of the seats.
0 Don’t leave an unsecured child restraint in
your vehicle.
0 When you carry something inside the
vehicle, secure it whenever you can.
0 Don’t leave a seat folded down unless you
need to.
If you put things inside your vehicle
-- like suitcases,
tools, packages, or anything else
-- they go as fast as the
vehicle goes. If
you have to stop or turn quickly, or if
there is a crash, they’ll keep going. There’s
also important loading information for off-road
driving in this manual. See “Loading
Your Vehicle for
Off-Road Driving” in the Index.
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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.
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.
Camper Wiring Harness (If Equipped)
A five-wire harness is stored in the front stake pocket on
the driver’s side of the bed. The harness has no connector
and should be wired by
a qualified electrical technician. It
must be routed out of your vehicle and securely attached
so that it won’t be pulled or rubbed while you’re using
it. Store the harness in its original position. Wrap the
harness together and tie
it neatly so it won’t be damaged.
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, first contact the GM Zone Office for your area for
information on such conversions specific to this vehicle.
(See the “Warranty and Owner Assistance” booklet for Zone
Office.) 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 the Zone Office.
Towing a Trailer
If you don’t use the correct equipment and drive
properly, you can lose control when you pull a
trailer. For example, if the trailer is too heavy, the
brakes may not work well
-- or even at all. You
and your passengers could be seriously injured.
Pull a trailer only if you have followed all the
steps in this section.
Ask your GM dealer for
advice and information about towing a trailer with your vehicle.
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Safety Chains
You should always attach chains between your vehicle
and your trailer. Cross the safety chains under the tongue
of the trailer so that the tongue will not drop to the road
if it becomes separated from
the hitch. Instructions
about safety chains may be provided by the hitch
manufacturer or by the trailer manufacturer. Follow the
manufacturer’s recommendation for attaching safety
chains and do not attach them to
the bumper. Always
leave just enough slack
so you can turn with your rig.
And, never allow safety chains to drag on the ground.
Trailer Brakes
If your trailer weighs more than 1,000 Ibs. (450 kg)
loaded, then it needs its own brakes
-- and they must be
adequate. Be sure
to read and follow the instructions for
the trailer brakes
so you’ll be able to install, adjust and
maintain them properly.
Your trailer brake system can tap into the vehicle’s
hydraulic brake system
only if:
The trailer parts can withstand 3,OOO psi (20 650 Wa)
of pressure.
The trailer’s brake system will use less than 0.02
cubic inch (0.3 cc) of fluid from your vehicle’s
master cylinder. Otherwise, both braking systems
won’t work well.
You could even lose your brakes.
If everything checks out this far, make the brake tap at the
port on the master cylinder that sends the fluid to the rear \
brakes. But don’t use copper tubing for this.
If you do, it
will bend and finally break off. Use steel brake tubing.
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.
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When You Are Ready to Leave After
Parkine
on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
Start your engine;
Shift into a gear; and
Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
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 fluid (don’t
overfill), engine oil, axle lubricant, belt, cooling system
and brake adjustment. Each
of these is covered in this
manual, and
the Index will help you find them quickly.
If you’re trailering, it’s a good idea to review these
sections before you start your trip.
Trailer Wiring Harness
A seven-wire harness is stored under the rear end of
your vehicle, between
the frame rails. An electrical
connector will need to be installed at the trailer end of
the harness, by a qualified electrical technician. For
additional trailer wiring and towing information please
consult your
GM dealer. 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
won’t bind or break when turning with the trailer, but
not
so loose that it drags on the ground. Store the
harness in its original position. Wrap the harness
together and tie
it neatly so it won’t be damaged. If you
tow
a trailer, your Center High-Mounted Stoplamp
(CHMSL) may not be properly visible from behind.
You
should select a trailer with a CHMSL on it or, if one is
not available, have one installed. See your
GM dealer
about how to connect your vehicle’s wiring
to a
trailer CHMSL.
Check periodically to see that all hitch nuts and bolts
are tight.
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I A CAUTION:
To help avoid injury to you or others:
0 Never let passengers ride in a vehicle that is
Never tow faster than safe or posted speeds.
Never tow with damaged parts not
fully secured.
Never get under your vehicle after it has
been lifted by the tow truck.
0 Always use separate safety chains on each
side when towing a vehicle.
For pickups (except cab chassis models),
use T-hooks on front of vehicle, J-hooks
on rear.
front and rear
of vehicle.
being
towed.
For cab chassis models, use J-hooks on
I [ CAUTION:
t
A vehicle can fall from a car carrier if it isn’t
adequately secured. This can cause a collision,
serious personal injury and vehicle damage. The
vehicle should be tightly secured with chains or
steel cables before
it is transported.
Don’t use substitutes (ropes, leather straps,
canvas webbing, etc.) that can be cut by sharp
edges underneath the towed vehicle.
Don’t have your vehicle towed
on the drive wheels
unless
you must. If the vehicle must be towed on the
drive wheels, be sure
to follow the speed and distance
restrictions later
in this section or your transmission will
be damaged.
If these limitations must be exceeded, then
the drive wheels have
to be supported on a dolly.
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