2003 GMC SONOMA ECU

{CAUTION:
Don’t keep driving if the oil pressure is low.
If you do, your engine can become so hot that
it catchesre. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Damage to your engine from neglected oil
problems can be costly and is not covered by
your warranty.
Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the
low pressure zone indicate the normal operating range.
A reading in the low pressure zone may be caused
by a dangerously low oil level or other problems causing
low oil pressure.
Security Light
This light will come on
briey when you turn the
key toward START.
The light will stay on until
the engine starts.
If the lightashes, the Passlock
®system has entered a
tamper mode. If the vehicle fails to start, seePasslock®
on page 2-19.
If the light comes on continuously while driving and
stays on, there may be a problem with the Passlock
®
system. Your vehicle will not be protected by Passlock®,
and you should see your dealer.
Also, seeContent Theft-Deterrent on page 2-17for
additional information regarding the SECURITY light.
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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 loadoor 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.
{CAUTION:
•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.
CAUTION: (Continued)
CAUTION: (Continued)
•
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’llnd other important information in this manual.
SeeLoading Your Vehicle on page 4-46,Luggage
Carrier on page 2-50andTires on page 5-58.
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Winter Driving
Here are some tips for winter driving:
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 washeruid, a rag, some winter
outer clothing, a small shovel, aashlight, a red
cloth and a couple of reective 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.
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Loading Your Vehicle
The Certication/Tire label is found on the driver’s
door edge, above the door latch. The label shows the
size of your original tires and the ination pressures
needed to obtain the gross weight capacity of your
vehicle. This is called the Gross Vehicle Weight
Rating (GVWR). The GVWR includes the weight of the
vehicle, all occupants, fuel, cargo and trailer tongue
weight, if pulling a trailer.The Certication/Tire label also tells you the maximum
weights for the front and rear axles, called Gross
Axle Weight Rating (GAWR). Tond 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.
Similar appearing vehicles may have different GVWRs
and payloads. Please note the Certication/Tire label on
your truck or consult your dealer for additional details.{CAUTION:
In the case of a sudden 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.
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{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, and it can change the way your vehicle
handles. These could cause you to lose
control and crash. Also, overloading can
shorten the life of your vehicle.
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.
Notice:Your warranty does not cover parts
or components that fail because of overloading.
If you put things inside your vehicle—like suitcases,
tools, packages, or anything else—they will 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.
{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.
•Don’t leave a seat folded down unless you
need to.
There’s also important loading information for off-road
driving in this manual. See“Loading Your Vehicle
for Off-Road Driving″underOff-Road Driving with Your
Four-Wheel-Drive Vehicle on page 4-13.
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Payload
This 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 left the 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. SeeLoading Your
Vehicle on page 4-46.
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.
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 rear axle. SeeLoading Your
Vehicle on page 4-46.
Add-On Equipment
When you carry removable items, you may need to put
a limit on how many people you carry inside your
vehicle. Be sure to weigh your vehicle before you buy
and install the new equipment.
Notice:Your warranty does not cover parts or
components that fail because of overloading.
Remember not to exceed the Gross Axle Weight
Rating (GAWR) of the rear axle. SeeLoading Your
Vehicle on page 4-46.
Truck-Camper Loading Information
The Truck-Camper Loading label is located on the
passenger’s door near the latch. It will tell you if your
vehicle can carry a slide-in camper, how much of a load
your vehicle can carry, and how to correctly spread
out your load. Also, it will help you match the right
slide-in camper to your vehicle.
When the truck is used to carry a slide-in camper, the
total cargo load of the truck consists of the
manufacturer’s camper weightgure, the weight of
installed additional camper equipment not included in
the manufacturer’s camper weightgure, the weight of
camper cargo, and the weight of passengers in the
camper. The total cargo load should not exceed
the truck’s cargo weight rating and the camper’s center
of gravity should fall within the truck’s recommended
center of gravity zone when installed.
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If your slide-in camper and its load weigh less than the
CWR, the center of gravity zone for your vehicle
may be larger.
Your dealer can help you make a good vehicle-camper
match. He’ll also help you determine your CWR.
Secure loose items to prevent weight shifts that could
affect the balance of your vehicle. When the truck
camper is loaded, drive to a scale and weigh on the
front and on the rear wheels separately to determine
axle loads. Individual axle loads should not exceed
either of the Gross Axle Weight Ratings (GAWR).
The total of the axle loads should not exceed the Gross
Vehicle weight Rating (GVWR). These ratings are
given on the vehicle certication label that is located on
the rear of the passenger’s door. If weight ratings
are exceeded, move or remove items to bring all weights
below the ratings.
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 load from the CWR for
your vehicle. Weigh your vehicle with your trailer
attached, so that you won’t go over the GVWR or
the 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, seeTowing a Trailer on page 4-51
later in this section.
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. However, we
recommend that conversions of this type not be done
to pickups. 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. For specic information on
this pickup, contact GM Customer Assistance. See
Customer Assistance Offices on page 7-4.
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Trailer Brakes
If your trailer weighs more than 1,000 lbs. (450 kg)
loaded, then it needs its own brake–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’s brake system can tap into the vehicle’s
hydraulic brake system only if:
The trailer parts can withstand 3,000 psi
(20 650 kPa) of pressure.
The trailer’s brake system will use less than
0.02 cubic inch (0.3 cc) ofuid 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, then make the brake
uid tap at the port on the master cylinder that
sendsuid to the rear brakes. But don’t use copper
tubing for this. If you do, it will bend andnally 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.
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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