Page 297 of 402

(E) Rim Diameter:Diameter of the wheel in
inches.
(F) Service Description
:The service description
indicates the load range and speed rating of a
tire. The load index can range from 1 to 279.
Speed ratings range from A to Z.
Tire Terminology and De nitions
Air Pressure:The amount of air inside the tire
pressing outward on each square inch of the tire.
Air pressure is expressed in pounds per square
inch (psi) or kilopascal (kPa).
Accessory Weight
:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of a tire’s height
to its width.
Belt
:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
Cold Tire Pressure
:The amount of air pressure
in a tire, measured in pounds per square inch (psi)
or kilopascals (kPa) before a tire has built up heat
from driving. SeeInflation - Tire Pressure on
page 5-60.
Curb Weight
:The weight of a motor vehicle with
standard and optional equipment including the
maximum capacity of fuel, oil, and coolant, but
without passengers and cargo.
DOT Markings
:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identification Number (TIN),
an alphanumeric designator which can also identify
the tire manufacturer, production plant, brand, and
date of production.
GVWR
:Gross Vehicle Weight Rating. See
Loading Your Vehicle on page 4-20.
GAWR FRT
:Gross Axle Weight Rating for the
front axle. SeeLoading Your Vehicle
on page 4-20.
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Page 348 of 402

Fuse Usage
9 Right Low-Beam Headlamp
10 Daytime Running Lamps 2 (DRL)
11Fuel System Control Module
Ignition (Gas)
12 Daytime Running Lamps 1 (DRL)
13 Auxiliary Stoplamp
14Fuel Operated Heater Module
(Diesel)
15Fuel System Control Module
Battery (Gas)
16 Left Stoplamp, Trailer Turn Signal
17 Canister Vent Solenoid (Gas)
18 Empty
19 Empty
20 Body Control Module 1
21 Special Equipment Option (SEO)
22 Body Control Module 4
23 Body Control Module 6
24 Empty
25 Body Control Module 7
26 Body Control Module 3
27 Body Control Module 5
28 Empty
29 EmptyFuse Usage
30 Instrument Panel Cluster
31 Empty
32 Brake Switch
33 Auxiliary Power Outlet
34 Airbag
35 Trailer Wiring
36 Steering Wheel Sensor (Gas)
37 Body Control Module 2
38Cigarette Lighter, Data Link
Controller
39 Windshield Wiper
40 Empty
41 Windshield Washer
42 Empty
43 Horn
44Transmission Control Module
Battery
45 Empty
46 Oxygen Sensor 1 (Gas)
47Transmission Control Module
Ignition
48 Engine Control Module Ignition
49 Mass Airflow Sensor, Canister Vent
50 Engine Control Module, Powertrain
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Page 349 of 402
Fuse Usage
51 Transmission
52 Even Ignition Injectors (Gas)
53 Glow Plug Module (Diesel)
54 Engine Control Module Battery
55 Odd Ignition Injectors (Gas)
56 Oxygen Sensor 2 (Gas)
57 Air Conditioning Compressor
58 Fan Clutch (Diesel)
59 V6 Fuel Injectors (Gas)
60Antilock Brake System Module
(J-Case)
61Antilock Brake System Motor
(J-Case)
62 Trailer Wiring (J-Case)
63 Empty
64 Starter Solenoid (J-Case)
65Engine Control Module (ECM),
Powertrain (Diesel) (J-Case)
66 Front Blower (J-Case)
67 Empty
77 Body BEC (Mega Fuse)Relays Usage
68 Empty
69 Run, Crank (High Current Micro)
70Windshield Wiper High
(High Current Micro)
71Windshield Wiper (High Current
Micro)
72 Fuel Pump (Mini Micro)
73 Crank (High Current Micro)
74Air Conditioning Compressor
(Mini Micro)
75 Fan Clutch (Diesel) (Solid State)
76 Powertrain (High Current Micro)
5-109
Page 351 of 402
ApplicationCapacities
English Metric
Fuel Tank
Standard Tank (Passenger and Cargo) 31.0 gal 117.3 L
Standard Tank (Cab and Chassis) 33.0 gal 124.9 L
Optional Tank (Cab and Chassis)* 57.0 gal 215.7 L
* 159 inch (4 039 mm) wheelbase or 177 inch (4 496 mm) wheelbase only
Transmission Capacities
4-SPD 4L60-E Transmission 5.0 qt 4.7 L
4-SPD 4L80-E 7.7 qt 7.3 L
4-SPD 4L80-E Heavy Duty Transmission 7.7 qt 7.3 L
Wheel Nut Torque 140 ft lb 190Y
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this
manual. Recheck fluid level after filling.
Engine Speci cations
Engine VIN Code Transmission Spark Plug Gap
VORTEC™ 4300 V6 X Automatic 0.060 inches (1.52 mm)
VORTEC™ 4800 V8 C Automatic 0.040 inches (1.01 mm)
VORTEC™ 5300 V8 4 Automatic 0.040 inches (1.01 mm)
VORTEC™ 6000 V8 K Automatic 0.040 inches (1.01 mm)
5-111
Page 357 of 402

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and filter. SeeEngine Oil (Gasoline Engine) on page 5-15.
Reset oil life system. SeeEngine Oil Life System on page 5-18.An Emission
Control Service.••
Lubricate chassis components.See footnote #.••
Visually check for any leaks or damage.See footnote (j).••
Inspect engine air cleaner filter. If necessary, replace filter. SeeEngine Air
Cleaner/Filter on page 5-19.See footnote (l).•
Rotate tires and check inflation pressures and wear. SeeTire Inspection and
Rotation on page 5-68and “Tire Wear Inspection” inAt Least Once a Month
on page 6-11.••
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.•
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Page 359 of 402
Additional Required Services (cont’d)
Service and Miles (Kilometers)25,000
(40 000)50,000
(80 000)75,000
(120 000)100,000
(160 000)125,000
(200 000)150,000
(240 000)
Change automatic transmission fluid
and filter (severe service).
See footnote (h).•••
Change automatic transmission fluid
and filter (normal service).•
Replace spark plugs and inspect spark
plug wires.An Emission Control
Service.•
Engine cooling system service (or every
five years, whichever occurs first).
An Emission Control Service.
See footnote (i).•
Inspect engine accessory drive belt.
An Emission Control Service.
See footnote (n).•
Inspect evaporative control system.
An Emission Control Service.
See footnotes † and (k).•••
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Page 361 of 402

(f)Lubricate all key lock cylinders, hood hinges, hood
prop rod pivot, hood latch assembly, secondary latch,
pivots, spring anchor, release pawl, rear compartment
hinges, latches, locks, fuel door hinge, and any moving
seat hardware. More frequent lubrication may be required
when exposed to a corrosive environment. Applying
silicone grease on weatherstrips with a clean cloth will
make them last longer, seal better, and not stick or
squeak.
(g)Vehicles with Gross Vehicle Weight Rating (GVWR)
above 10,000 lbs (4 536 kg) only: Inspect shields for
damage or looseness. Adjust or replace as required.
This is a Noise Emission Control Service. Applicable to
vehicles sold in the United States and recommended
for vehicles sold in Canada.
(h)Change automatic transmission fluid and filter if the
vehicle is mainly driven under one or more of these
conditions:
-In heavy city traffic where the outside temperature
regularly reaches 90°F (32°C) or higher.
-In hilly or mountainous terrain.
-When doing frequent trailer towing.
-Uses such as found in taxi, police, or delivery
service.(i)Drain, flush, and refill cooling system. This service can
be complex; you should have your dealer/retailer perform
this service. See Engine Coolant on page 5-23 for what to
use. Inspect hoses. Clean radiator, condenser, pressure
cap, and filler neck. Pressure test the cooling system and
pressure cap.
(j)A fluid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the fluid level checked. Add fluid if needed.
(k)Inspect system. Check all fuel and vapor lines and
hoses for proper hook-up, routing, and condition. Check
that the purge valve works properly, if equipped.
Replace as needed.
(l)If you drive regularly under dusty conditions, inspect
the filter at each engine oil change.
(m)Check system for interference or binding and for
damaged or missing parts. Replace parts as needed.
Replace any components that have high effort or
excessive wear. Do not lubricate accelerator or cruise
control cables.
(n)Visually inspect belt for fraying, excessive cracks, or
obvious damage. Replace belt if necessary.
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Page 364 of 402

Automatic Transmission Shift Lock
Control System 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. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-26.
Be ready to apply the regular brake immediately if
the vehicle begins to move.3. With the engine off, turn the ignition to ON/RUN,
but do not start the engine. Without applying the
regular brake, try to move the shift lever out
of PARK (P) with normal effort. If the shift lever
moves out of PARK (P), contact your dealer/retailer
for service.Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition to LOCK/OFF in each shift lever position.
•The ignition should turn to LOCK/OFF only
when the shift lever is in PARK (P).
•The ignition key should come out only in
LOCK/OFF.
Contact your dealer/retailer if service is required.
6-12