Page 275 of 406

If the temperature overheat gage is no longer in the
overheat zone or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive
the vehicle slow for about 10 minutes. Keep a safe
vehicle distance from the car in front of you. If the
warning does not come back on, continue to drive
normally.
If the warning continues, pull over, stop, and park the
vehicle right away.
If there is still no sign of steam, push down the
accelerator until the engine speed is about twice
as fast as normal idle speed for at least three minutes
while you are parked. If you still have the warning,
turn off the engine until it cools down.
You may decide not to lift the hood but to get service
help right away.Engine Fan Noise
Your vehicle has a clutched engine cooling fan.
When the clutch is engaged, the fan spins faster to
provide more air to cool the engine. In most everyday
driving conditions, the fan is spinning slower and the
clutch is not fully engaged. This improves fuel economy
and reduces fan noise. Under heavy vehicle loading,
trailer towing, and/or high outside temperatures, the fan
speed increases as the clutch more fully engages, so you
may hear an increase in fan noise. This is normal and
should not be mistaken as the transmission slipping or
making extra shifts. It is merely the cooling system
functioning properly. The fan will slow down when
additional cooling is not required and the clutch partially
disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
5-33
Page 282 of 406

Jump Starting
If the vehicle battery has run down, you may want
to use another vehicle and some jumper cables to start
your vehicle. Be sure to use the following steps to
do it safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
•They contain acid that can burn you.
•They contain gas that can explode or ignite.
•They contain enough electricity to burn you.
If you do not follow these steps exactly, some or
all of these things can hurt you.Notice:Ignoring these steps could result in costly
damage to the vehicle that would not be covered
by the warranty.
Trying to start the vehicle by pushing or pulling it
will not work, and it could damage the vehicle.
1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
Notice:If the other vehicle’s system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles are not touching
each other. If they are, it could cause a ground
connection you do not want. You would not be
able to start your vehicle, and the bad grounding
could damage the electrical systems.
To avoid the possibility of the vehicles rolling,
set the parking brake firmly on both vehicles
involved in the jump start procedure. Put an
automatic transmission in P (PARK) or a manual
transmission in NEUTRAL before setting the
parking brake.
5-40
Page 302 of 406

(D) Construction Code:A letter code is used
to indicate the type of ply construction in the tire.
The letter R means radial ply construction;
the letter D means diagonal or bias ply construction;
and the letter B means belted-bias ply construction.
(E) Rim Diameter
:Diameter of the wheel in
inches.
(F) Load Range
:Load Range.
(G) Service Description
:The service description
indicates the load index and speed rating of a tire.
If two numbers are given as in the example,
120/116, then this represents the load index for
single versus dual wheel usage (single/dual).
The speed rating is the maximum speed a tire is
certified to carry a load. This does not apply to
Goodyear LT225/75R16 G949 RSA and Goodyear
LT225/75R16 G933 RSD commercial truck tires;
see the dual tire and single tire maximum load and
load range letter designations on the tire sidewall.
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 5-63.
5-60
Page 350 of 406

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
5-108
Page 351 of 406
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)Fuse Usage
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 353 of 406
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 Fluid
4-SPD 4L60-E 5.0 qt 4.7 L
4-SPD 4L80-E (Standard and Heavy Duty) 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
4.3L V6 X Automatic 0.060 in (1.52 mm)
4.8L V8 C Automatic 0.040 in (1.01 mm)
5.3L V8 4 Automatic 0.040 in (1.01 mm)
6.0L V8 K Automatic 0.040 in (1.01 mm)
5-111
Page 359 of 406

Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and filter. SeeEngine Oil 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 5-20.See footnote (l).•
Rotate tires and check inflation pressures and wear. SeeTire Inspection and
Rotation on page 5-70and “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.•
Inspect shields, vehicles with GVWR above 10,000 lbs (4 536 kg) only.
See footnote (g).•
Inspect throttle system.See footnote (m).•
6-5
Page 360 of 406

Additional Required Services
This maintenance section applies to vehicles with a gasoline engine. If your vehicle has a diesel engine, see the
maintenance schedule section in the DURAMAX®Diesel manual.
The following services should be performed at the first maintenance service (IorII) after the indicated miles
(kilometers) shown for each item.
Additional Required Services
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)
Inspect fuel system for damage or leaks.• •••••
Inspect exhaust system for loose or
damaged components.• •••••
Replace engine air cleaner filter. See
Engine Air Cleaner/Filter on page 5-20.•••
Change automatic transmission fluid and
filter (severe service).See footnote (h).•••
Change automatic transmission fluid and
filter (normal service).•
Four-wheel drive: Change transfer case
fluid (severe service).See footnotes (o)
and (p).•••
Four-wheel drive: Change transfer case
fluid (normal service).See footnote (o).•
6-6