Page 398 of 614

And, if you do have a heavy load, you should
spread it out.
{CAUTION:
Do not load the vehicle any heavier than
the Gross Vehicle Weight Rating (GVWR),
or either the maximum front or rear Gross
Axle Weight Rating (GAWR). If you do, parts
on the 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 the
vehicle.
Notice :Overloading the vehicle may cause
damage. Repairs would not be covered by the
vehicle warranty. Do not overload the vehicle.
The label will help you decide how much cargo
and installed equipment your truck can carry.
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. 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 will keep going.
{WARNING:
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 cargo area of your
vehicle. 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.
.Do not leave an unsecured child restraint
in your vehicle.
.When you carry something inside the
vehicle, secure it whenever you can.
.Do not leave a seat folded down unless
you need to.
5-36
Page 410 of 614

Level Control
Automatic Level Control
The automatic level control rear suspension is available
on light‐duty vehicles and comes as a part of the
Autoride
®suspension, if equipped.
This type of level control is fully automatic and will
provide a better leveled riding position as well as
better handling under a variety of passenger and
loading conditions. An air compressor connected to
the rear shocks will raise or lower the rear of the
vehicle to maintain proper vehicle height. The system
is activated when the ignition key is turned to ON/RUN
and will automatically adjust vehicle height thereafter.
The system may exhaust (lower vehicle height) for up
to ten minutes after the ignition key has been turned off.
You may hear the air compressor operating when the
height is being adjusted.
If a weight‐distributing hitch is being used, it is
recommended to allow the shocks to inflate, thereby
leveling the vehicle prior to adjusting the hitch.
Autoride®
With this feature, improved vehicle ride and handling is
provided under a variety of passenger and loading
conditions.
The system is fully automatic and uses a computer
controller to continuously monitor vehicle speed, wheel
to body position, lift/dive and steering position of the
vehicle. The controller then sends signals to each shock
absorber to independently adjust the damping level to
provide the optimum vehicle ride.
Autoride also interacts with the tow/haul mode that,
when activated, will provide additional control of the
shock absorbers. This additional control results in better
ride and handling characteristics when the vehicle is
loaded or towing a trailer. See “Tow/Haul Mode”under
Towing a Trailer
on page 5‑49for more information.
5-48
Page 564 of 614

When the Change Engine Oil Soon message displays,
certain services, checks, and inspections are required.
The services described for MaintenanceIshould be
performed at every engine oil change. The services
described for Maintenance IIshould be
performed when:
.Maintenance Iwas performed the last time the
engine oil was changed.
.It has been 10 months or more since the Change
Engine Oil Soon message has displayed or since
the last service.
Maintenance I
.Change engine oil and filter. See Engine Oilon
page 6‑18. An Emission Control Service.
.Engine coolant level check. See Engine Coolanton page 6‑32.
.Windshield washer fluid level check.
SeeWindshield Washer Fluid on page 6‑41.
.Tire inflation check. See Inflation - Tire Pressureon page 6‑72.
.Tire wear inspection. See Tire Inspection and
Rotation on page 6‑78.
.Rotate tires. See Tire Inspection and Rotationon
page 6‑78.
.Fluids visual leak check (or every 12 months,
whichever occurs first). A leak in any system must
be repaired and the fluid level checked.
.Engine air cleaner filter inspection (vehicles driven
in dusty conditions only). See Engine Air Cleaner/
Filter on page 6‑22.
.Brake system inspection (or every 12 months,
whichever occurs first).
Maintenance II
.Perform all services described in Maintenance I.
.Steering and suspension inspection. Visual
inspection for damaged, loose, or missing parts
or signs of wear.
.Lubricate the front suspension, steering linkage,
and parking brake cable guides. Control arm
ball joints on 2500 series vehicles require
lubrication but should not be lubricated unless
their temperature is−12°C (10°F) or higher, or
they could be damaged. Control arm ball joints
on 1500 series vehicles are maintenance‐free.
.Engine cooling system inspection. Visual
inspection of hoses, pipes, fittings, and clamps
and replacement, if needed.
7-4
Page 568 of 614
Scheduled Maintenance
ServiceMaintenanceIMaintenance II
Change engine oil and filter. Reset oil life system. • •
Engine coolant level check. ••
Windshield washer fluid level check. ••
Tire inflation pressures check. ••
Tire wear inspection. ••
Rotate tires. ••
Fluids visual leak check. ••
Engine air cleaner filter inspection (vehicles driven in dusty conditions only). ••
Brake system inspection. ••
Steering and suspension inspection. •
Chassis components lubrication. •
Engine cooling system inspection. •
Windshield wiper blades inspection. •
Body components lubrication. •
Restraint system components check. •
Automatic transmission fluid level check. •
Four‐wheel drive only: Transfer case fluid level check. •
Engine air cleaner filter inspection (vehicles not driven in dusty conditions). •
7-8
Page 594 of 614

Reporting Safety Defects to
General Motors
In addition to notifying NHTSA (or Transport Canada) in
a situation like this, please notify General Motors.
Call 1-800-GMC-8782 (1-800-462-8782), or write:GMC Customer Assistance Center
P.O. Box 33172
Detroit, MI 48232-5172
In Canada, call 1-800-263-3777 (English) or
1-800-263-7854 (French), or write: General Motors of Canada Limited
Customer Communication Centre, CA1-163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Service Publications Ordering
Information
Service Manuals
Service Manuals have the diagnosis and repair
information on engines, transmission, axle suspension,
brakes, electrical, steering, body, etc.
Service Bulletins
Service Bulletins give additional technical service
information needed to knowledgeably service
General Motors cars and trucks. Each bulletin contains
instructions to assist in the diagnosis and service of
your vehicle.
Owner Information
Owner publications are written specifically for owners
and intended to provide basic operational information
about the vehicle. The owner manual includes the
Maintenance Schedule for all models.
In-Portfolio: Includes a Portfolio, Owner Manual, and
Warranty Booklet.
RETAIL SELL PRICE: $35.00 (U.S.) plus processing fee
Without Portfolio: Owner Manual only.
RETAIL SELL PRICE: $25.00 (U.S.) plus processing fee
8-16