
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.
If a Tire Goes Flat
It is unusual for a tire to blowout while you are driving,
especially if you maintain your tires properly. If air
goes out of a tire, it is much more likely to leak out
slowly. But if you should ever have a blowout, 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 blowout, particularly on a curve, acts much like a
skid and may require the same correction you would
use in a skid. In any rear blowout, 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 turn on your
hazard warning flashers. SeeHazard Warning Flashers
on page 3-6.
{CAUTION:
Your vehicle, when new, did not include tire
changing equipment or a place to store a tire
in the vehicle. Special tools and procedures
are required if a tire needs to be serviced. If
these tools and procedures are not used, you
or others could be injured or killed while trying
to change or service a truck tire.
5-82

Instrument Panel Fuse Block
There are two instrument panel fuse blocks located behind the instrument panel on the passenger’s side of the
vehicle. Be sure to replace fuses with fuses of the same rating. Do not use fuses of higher amperage than those
indicated on the fuse block.
Circuit Breaker Usage
1 Stoplamps
2 Center High-Mounted Stoplamp
3 Parking Lamps
4 Powertrain Control ModuleCircuit Breaker Usage
5 Auxiliary Wiring
6 Heater/Air Conditioning
7 Hazard Warning Flashers
8 Power Post
5-94

Circuit Breaker Usage
9 Courtesy Lamps
10Warning Lights, Gages and
Indicators
11 Starter
12 Rear Axle/Four-Wheel-Drive
13Trailer Turn Signals/Hazard
Warning Flashers
14 Radio/Chime
15 Daytime Running Lamps
16 Airbag System
17 Exterior/Interior Lamps
18 Parking Brake
19 Accessory Power
20 Ignition 4
21 Sidemarker Lamps
22 Turn Signal/Backup Lamps
23 Transmission
24 Hydraulics/Air Brake
A Spare
B SpareFuse Usage
HTD/MIRR Heated Mirrors
Blank Not Used
RT TRN TRLR Passenger’s Side Trailer Turn Signal
Blank Not Used
LT TRN TRLR Driver’s Side Trailer Turn Signal
Blank Not Used
BRK Brake Warning Lamp
RT PRK Passenger’s Side Parking Lamps
Blank Not Used
Blank Not Used
Blank Not Used
LT PARK Driver’s Side Parking Lamps
Blank Not Used
RT REAR
TRN/STOPPassenger’s Side Rear Turn
Signal/Stoplamp
LT REAR
TRN/STOPDriver’s Side Rear Turn
Signal/Stoplamp
RADIO Radio
Blank Not Used
5-95

Relay Usage
NOTE 1LG4 Powertrain Control Valve,
L18 Fuel Pump, LG5 Heated Fuel
IGN B Ignition
STARTER Starter
HORN Horn
IGN A Ignition
PTO/ECU*Power Take-Off/Engine Control Unit
*Diesel 7.8L DURAMAX
®
REVERSE Reverse
NEUTRAL
STARTNeutral Start
Fuse Usage
IGN 1 Four-Wheel Drive Module
IGN 4 Ignition 4
IGN 3 Ignition 3
BATT/HAZ Battery/Hazard Warning Flashers
HEADLAMP Headlamps
LIGHTING Interior/Exterior Lamps
HVAC Climate Control System
NOTEC4/C5 Electric Brake,
C6/C7/C8 Brake Lamps Secondary Underhood
Fuse Block
5-98

Starter Switch Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brakes.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only
in PARK (P), if equipped, or NEUTRAL (N). If
the starter works in any other position, your vehicle
needs service. On manual transmission vehicles,
the starter should work only when the clutch pedal is
all the way down.
Automatic Transmission Shift
Indicator Check
Check that the indicator points to the gear chosen.
Steering Check
Be alert for any changes in steering action, abnormal
front tire wear or steering wheel position. An inspection
or service is needed when the steering wheel is
harder to turn or has too much free play, or if there are
strange sounds when turning or parking.
Brake System Check
Be alert to illumination of the low air warning lamp or for
the tone alarm, or changes in braking action, such as
repeated pulling to one side, unusual sounds when
braking or increased brake pedal travel. Make sure air
brake system reservoirs are drained daily with full
system air pressure, and check system for leaks. Any of
these conditions could indicate the need for brake
system inspection and/or service.
Engine Cooling System Service
Inspect the hoses and have them replaced if they are
cracked, swollen, or deteriorated. Inspect all pipes,
fittings, and clamps; replace as needed. Clean
the outside of the radiator and air conditioning
condenser. To help ensure proper operation, a pressure
test of the cooling system and pressure cap is
recommended at least once a year.
6-30

Exhaust System Check
Be alert for any changes in the sound of the exhaust
system or any smell of fumes. These are signs the
system may be leaking. Have it checked and/or repaired
at once. Refer toEngine Exhaust on page 2-45and
Running the Engine While Parked on page 2-46.
Windshield Wipers and Washers Check
Check operation and condition of the wiper blades.
Check the flow of the washer spray.
Defroster Check
Move the control to the defrost symbol and the fan to
HI or the high symbol. Then check the airflow from
the ducts at the inside base of the windshield.
Mirrors and Sun Visors Check
Check that friction joints hold mirrors and sun visors in
place.
Seat Adjuster Check
When adjusting a manual seat, be sure seat adjusters
latch by attempting to move the seat after latching.
Lamps Check
Check panel lighting, warning lights, indicator lights, and
interior lamps. On the outside, check: license plate
lamps, sidemarker lamps, reflectors or lights on outside
mirrors, headlamps, parking lamps, identification and
clearance lamps, taillamps, brake lamps, turn signals,
backup lamps, and hazard warning flashers. Have
headlamp aim checked at once if beams seem
improperly aimed.
Glass, Mirrors, Lamps and/or
Re ectors Condition Check
Look for broken, scratched, dirty, or damaged glass,
mirrors, lamps, or reflectors that could reduce the view
or visibility or cause injury. Replace, clean or repair
promptly.
Door Latches Check
Check that doors close, latch, and lock tightly. Check for
broken, damaged, or missing parts that might prevent
tight latching.
6-31

A
Accessory Power Outlet(s)...............................3-19
Adding a Snow Plow or Similar Equipment.........4-36
Adding Equipment to Your Airbag-Equipped
Vehicle.......................................................1-61
Additives, Fuel................................................. 5-6
Add-On Electrical Equipment............................5-92
Air Brake.......................................................2-42
Air Cleaner/Filter, Engine.................................5-35
Air Conditioning..............................................3-20
Air Conditioning System...................................5-74
Air Pressure Gage..........................................3-47
Air Shift Control..............................................2-29
Air Suspension...............................................2-44
Air Suspension Seats........................................ 1-6
Airbag
Off Light.....................................................3-30
Readiness Light..........................................3-29
Airbag Sensing and Diagnostic Module (SDM)........ 7-6
Airbag System................................................1-50
Adding Equipment to Your Airbag-Equipped
Vehicle...................................................1-61
Airbag Off Switch........................................1-58
How Does an Airbag Restrain?......................1-56
Servicing Your Airbag-Equipped Vehicle..........1-61
What Makes an Airbag Inflate?......................1-56
What Will You See After an Airbag Inflates?....1-56Airbag System (cont.)
When Should an Airbag Inflate?....................1-55
Where Are the Airbags?...............................1-54
AM-FM Radio.................................................3-50
Antenna, Fixed Mast.......................................3-67
Anti-Lock Brake System (ABS)........................... 4-8
Anti-Lock Brake, System Warning Light..............3-35
Anti-Lock Brakes, Trailer System
Warning Light.............................................3-36
Appearance Care
Aluminum or Chrome-Plated Wheels..............5-89
Care of Safety Belts....................................5-86
Chemical Paint Spotting...............................5-90
Cleaning Exterior Lamps/Lenses....................5-87
Cleaning the Inside of Your Vehicle................5-83
Fabric/Carpet..............................................5-85
Finish Care.................................................5-87
Finish Damage............................................5-89
Instrument Panel, Vinyl, and Other
Plastic Surfaces.......................................5-86
Sheet Metal Damage...................................5-89
Tires..........................................................5-89
Underbody Maintenance...............................5-90
Vehicle Care/Appearance Materials................5-90
Washing Your Vehicle...................................5-87
Weatherstrips..............................................5-86
Windshield and Wiper Blades........................5-88
Ashtray(s)......................................................3-20
1

Audio System(s).............................................3-48
AM-FM Radio.............................................3-50
Care of Your Cassette Tape Player................3-65
Care of Your CD Player...............................3-67
Care of Your CDs ........................................3-66
Chime Level Adjustment...............................3-67
Fixed Mast Antenna.....................................3-67
Radio with Cassette.....................................3-53
Radio with CD............................................3-59
Setting the Time..........................................3-49
Theft-Deterrent Feature................................3-64
Understanding Radio Reception.....................3-64
Automatic Ether Injection System......................5-72
Automatic Transmission
Fluid..........................................................5-36
Operation...................................................2-30
Axle, Two-Speed Rear Axle Electric
Shift Control...............................................2-28
B
Battery..........................................................5-58
Bench Seat, Split............................................. 1-6
Brake
Anti-Lock Brake System (ABS)........................ 4-8
Diesel Engine Exhaust.................................2-27
Emergencies................................................ 4-9
Exhaust Indicator Light.................................3-41Brake (cont.)
Hydraulic Systems......................................... 4-7
System Warning Light..................................3-33
Trailer Hand Control Valve............................4-10
Brakes..........................................................5-49
Air .............................................................2-42
Hydraulic....................................................2-40
Propshaft Brake Burnish Procedure................2-41
Braking........................................................... 4-6
Braking in Emergencies..................................... 4-9
Break-In, New Vehicle.....................................2-11
Bucket Seats................................................... 1-2
Bulb Replacement...........................................5-68
C
California Proposition 65 Warning....................... 5-3
Canadian Owners................................................ ii
Capacities and Specifications............................5-99
Carbon Monoxide...................................2-45, 4-27
Care of
Safety Belts................................................5-86
Your Cassette Tape Player............................3-65
Your CD Player...........................................3-67
Your CDs ...................................................3-66
Center Console Storage Area...........................2-49
Center Passenger Position, Safety Belts.............1-24
Charging System Light....................................3-31
2