Page 310 of 390

Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this may
affect the way your vehicle performs, including its
braking, ride and handling characteristics, stability and
resistance to rollover. Additionally, if your vehicle
has electronic systems such as, anti-lock brakes,
traction control, and electronic stability control, the
performance of these systems can be affected.
{CAUTION:
If you add different sized wheels, your vehicle
may not provide an acceptable level of
performance and safety if tires not
recommended for those wheels are selected.
You may increase the chance that you will
crash and suffer serious injury. Only use GM
speci c wheel and tire systems developed for
your vehicle, and have them properly installed
by a GM certi ed technician.
SeeBuying New Tires on page 5-60andAccessories
and Modi cations on page 5-3for additional information.
Uniform Tire Quality Grading
Quality grades can be found where applicable on the
tire sidewall between tread shoulder and maximum
section width. For example:
Treadwear 200 Traction AA Temperature A
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, which grades tires by
treadwear, traction and temperature performance. (This
applies only to vehicles sold in the United States.)
The grades are molded on the sidewalls of most
passenger car tires. The Uniform Tire Quality Grading
system does not apply to deep tread, winter-type
snow tires, space-saver or temporary use spare tires,
tires with nominal rim diameters of 10 to 12 inches
(25 to 30 cm), or to some limited-production tires.
While the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform to federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
5-62
Page 312 of 390

Wheel Replacement
Replace any wheel that is bent, cracked, or badly rusted
or corroded. If wheel nuts keep coming loose, the
wheel, wheel bolts and wheel nuts should be replaced.
If the wheel leaks air, replace it (except some
aluminum wheels, which can sometimes be repaired).
See your dealer if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load-carrying
capacity, diameter, width, offset and be mounted
the same way as the one it replaces.
If you need to replace any of your wheels, wheel
bolts or wheel nuts, replace them only with new
GM original equipment parts. This way, you will be sure
to have the right wheel, wheel bolts and wheel nuts
for your vehicle.{CAUTION:
Using the wrong replacement wheels, wheel
bolts, or wheel nuts on your vehicle can be
dangerous. It could affect the braking and
handling of your vehicle, make your tires lose
air and make you lose control. You could have
a collision in which you or others could be
injured. Always use the correct wheel, wheel
bolts and wheel nuts for replacement.
Notice:The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance and tire clearance to the
body and chassis.
5-64
Page 313 of 390

{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause a crash. When you change
a wheel, remove any rust or dirt from places
where the wheel attaches to the vehicle. In an
emergency, you can use a cloth or a paper
towel to do this; but be sure to use a scraper
or wire brush later, if you need to, to get all the
rust or dirt off.
{CAUTION:
Never use oil or grease on studs or the
threads of the wheel nuts. If you do, the wheel
nuts might come loose and the wheel could
fall off, causing a crash.
{CAUTION:
Incorrect wheel nuts or improperly tightened
wheel nuts can cause the wheel to become
loose and even come off. This could lead to a
crash. Be sure to use the correct wheel nuts. If
you have to replace them, be sure to get new
GM original equipment wheel nuts.
Notice:Improperly tightened wheel nuts can lead
to brake pulsation and rotor damage. To avoid
expensive brake repairs, evenly tighten the wheel
nuts in the proper sequence and to the proper
torque speci cation.
5-65
Page 314 of 390

Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has been
used or how far it has been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
{CAUTION:
Do not use tire chains. There is not enough
clearance. Tire chains used on a vehicle without
the proper amount of clearance can cause
damage to the brakes, suspension or other
vehicle parts. The area damaged by the tire
chains could cause you to lose control of your
vehicle and you or others may be injured in a
crash. Use another type of traction device only
if its manufacturer recommends it for use on
your vehicle and tire size combination and road
conditions. Follow that manufacturer’s
instructions. To help avoid damage to your
vehicle, drive slowly, re-adjust or remove the
device if it is contacting your vehicle, and do
not spin your wheels. If you do nd traction
devices that will t, install them on the
rear tires.
5-66
Page 315 of 390

If a Tire Goes Flat
Your vehicle has no spare tire, no tire changing
equipment and no place to store a tire.
It is unusual for a tire to blow out while you are driving,
especially if you maintain your tires properly. See
Tires on page 5-51. If air goes out of a tire, it’s much
more likely to leak out slowly. But if you should
ever have a blow out here are a few tips about what to
expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blow out, particularly on a curve, acts much like
a skid and may require the same correction you
would use in a skid. In any rear blow out, remove your
foot from the accelerator pedal. Get the vehicle
under control by steering the way you want the vehicle
to go. It may be very bumpy and noisy, but you can
still steer. Gently brake to a stop, well off the road
if possible.If a tire goes flat, avoid further tire and wheel damage by
driving slowly to a level place and stopping. Then do this:
1. Turn on the hazard warning flashers.
2. Park your vehicle. If your vehicle has an automatic
transmission, set the parking brake firmly and put the
shift lever in PARK (P). SeeShifting Into Park (P) on
page 2-23for additional information. If your vehicle
has a manual transmission, move the shift lever to
REVERSE (R) and set the parking brake firmly. See
Parking Your Vehicle (Manual Transmission) on
page 2-25for additional information.
3. Turn off the engine.
4. Inspect the flat tire.
If the tire has been separated from the wheel or has
damaged sidewalls or large tears that allow rapid
air loss, call a tire repair facility. SeeRoadside
Assistance Program on page 7-6.
5-67
Page 337 of 390
Fuses Usage
29 Transmission Control Module
31 Truck Body Controller
32 Remote Keyless Entry (RKE)
33 Windshield Wipers
34 Stoplamps
35 Blank
36Climate Control System, Driver’s
Door Unlock
37 Front Parking Lamps
38 Driver’s Side Turn Signal
39 Climate Control System
40 Truck Body Controller
41 Radio
42 Trailer Parking Lamps
43 Passenger’s Side Turn Signal
44 Blank
46 Accessory Power Outlets
47 IgnitionFuses Usage
48 Blank
49 Blank
50 Truck Body Controller, Ignition
51 Brakes
52 Blank
Relays Usage
18 Locks
24 Unlock
30 Parking Lamps
45Rear Window Defogger, Outside
Power Heated Mirrors
Circuit
BreakersUsage
01 Roof & Door Module
02 Roof Pump
08 Power Seats
5-89
Page 339 of 390

Fuses Usage
4 Driver’s Side High Beam Headlamp
5 Driver’s Side Low Beam Headlamp
6 Cargo Cover Release
7Transmission Control
Module/Canister
8 Truck Body Controller
9 Windshield Washer
10 Driver’s Side Stoplamp/Turn Signals
11 Fuel Pump
12 Fog Lamps
13 Stoplamps
14 Headlamp Driver Module (HDM)
15Passenger’s Side Stoplamp/Turn
Signals
16 Cigarette Lighter
17 Hazard Warning Flashers
18 Coils
19 Truck Body Control, Ignition 1
20 Starter
21 Airbag System
22 Horn
23 Ignition EFuses Usage
24Instrument Panel Cluster, Driver
Information Center (DIC)
25Automatic Transmission Shift
Interlock Control System
26 Back-up lamps, Lock Out
27 Engine Control Module
28 Oxygen Sensor B
29 Injector B
30 Air Conditioning
31Engine Control Module (ECM),
Transmission Control Module (TCM)
32 Transmission
33 Engine 1
34Engine Control Module, Electronic
Brake Controller
35 Oxygen Sensor A
36 Injector A
37 Engine Cooling Fan
38 Anti-lock Brake System (ABS)
39 Ignition A
40 Climate Control Fan
41 Ignition B
5-91
Page 349 of 390
Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and filter. SeeEngine Oil on page 5-13. Reset oil
life system. SeeEngine Oil Life System on page 5-16.An Emission
Control Service.••
Visually check for any leaks or damage.See footnote (g).••
Inspect engine air cleaner filter. If necessary, replace filter. SeeEngine Air
Cleaner/Filter on page 5-18.See footnote (j).•
Check tire inflation pressures and tire wear. SeeTires on page 5-51.••
Inspect brake system.See footnote (a).••
Check engine coolant and windshield washer fluid levels and add fluid
as needed.••
Perform any needed additional services. See “Additional Required Services”
in this section.••
Inspect suspension and steering components.See footnote (b).•
Inspect engine cooling system.See footnote (c).•
Inspect wiper blades.See footnote (d).•
Inspect restraint system components.See footnote (e).•
Lubricate body components.See footnote (f).•
Check transmission fluid level and add fluid as needed.•
6-5