Page 421 of 556
6. Then replace the
pressure cap. Be sure
the pressure cap is
hand-tight and
fully seated.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
disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
5-41
Page 450 of 556

·Tire overloading
·Bad wear
·Bad handling
·Bad fuel economy
If your tires have too much air (overin¯ation), you
can get the following:
·Unusual wear
·Bad handling
·Rough ride
·Needless damage from road hazards
When to Check
Check your tires once a month or more.
Also, check the tire pressure of the spare tire.
How to Check
Use a good quality pocket-type gage to check tire
pressure. You can't tell if your tires are properly in¯ated
simply by looking at them. Radial tires may look
properly in¯ated even when they're underin¯ated.Remove the valve cap from the tire valve stem. Press
the tire gage ®rmly onto the valve to get a pressure
measurement. If the cold tire in¯ation pressure is low,
add air until you reach the recommended amount.
If you over®ll the tire, release air by pushing on the metal
stem in the center of the tire valve. Recheck the tire
pressure with the tire gage.
Be sure to put the valve caps back on the valve stems.
They help prevent leaks by keeping out dirt and
moisture.
Dual Tire Operation
When the vehicle is new, or whenever a wheel, wheel
bolt or wheel nut is replaced, check the wheel nut torque
after 100, 1,000 and 6,000 miles (160, 1 600 and
10 000 km) of driving. For proper torque and wheel nut
tightening information, see ªRemoving the Flat Tire
and Installing the Spare Tireº in the index.
The outer tire on a dual wheel setup generally wears
faster than the inner tire. Your tires will wear more
evenly and last longer if you rotate the tires periodically.
See ªTire Inspection and Rotationº earlier in this
section. Also see ªScheduled Maintenance Servicesº in
the Index for scheduled rotation intervals
5-70
Page 486 of 556

Finish Damage
Any stone chips, fractures or deep scratches in the
®nish should be repaired right away. Bare metal
will corrode quickly and may develop into major repair
expense.
Minor chips and scratches can be repaired with touch-up
materials avaliable from your dealer. Larger areas of
®nish damage can be corrected in your dealer's
body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are not
removed, corrosion and rust can develop on the
underbody parts such as fuel lines, frame, ¯oor pan and
exhaust system even though they have corrosion
protection.At least every spring, ¯ush these materials from the
underbody with plain water. Clean any areas where mud
and debris can collect. Dirt packed in close areas of
the frame should be loosened before being ¯ushed.
Your dealer or an underbody car washing system can
do this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces on your vehicle. This damage
can take two forms: blotchy, ring-shaped discolorations,
and small, irregular dark spots etched into the paint
surface.
Although no defect in the paint job causes this, GM will
repair, at no charge to the owner, the surfaces of
new vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs ®rst.
5-106
Page 495 of 556

*1Ð Gasoline Engine and Diesel Engine.
*2Ð Gasoline Engine; ECMRPV Ð Diesel Engine.
*3Ð Gasoline Engine; FUEL HT Ð Diesel Engine.
*4Ð Gasoline Engine; ECM I Ð Diesel Engine.
*5Ð IGN/EDU
Fuses Usage
GLOW PLUGDiesel Glow Plugs and Intake
Air Heater
CUST FEED Gasoline Accessory Power
STUD #1Auxiliary Power (Single
Battery and Diesels Only)/
Dual Battery (TP2) Do not
install fuse.
MBECMid Bussed Electrical Center
Power Feed, Front Seats,
Right Doors
BLOWER Front Climate Control Fan
LBECLeft Bussed Electrical Center,
Door Modules, Door Locks,
Auxiliary Power OutletÐRear
Cargo Area and Instrument
Panel
Fuses Usage
STUD 2Accessory Power/Trailer
Wiring Brake Feed
ABS Anti-Lock Brakes
VSES/ECAS Vehicle Stability
IGN A Ignition Power
IGN B Ignition Power
LBEC 1Left Bussed Electrical Center,
Left Doors, Truck Body
Controller, Flasher Module
TRL PARK Parking Lamps Trailer Wiring
RR PARKRight Rear Parking and
Sidemarker Lamps
LR PARKLeft Rear Parking and
Sidemarker Lamps
PARK LP Parking Lamps Relay
STARTER Starter Relay
INTPARK Interior Lamps
STOP LP Stoplamps
TBC BATTTruck Body Controller Battery
Feed
SUNROOF Sunroof
5-115
Page 496 of 556

Fuses Usage
SEO B2 Off-Road Lamps
4WSVent Solenoid
Canister/Quadrasteer Module
Power
RR HVAC Not Used
AUX PWRAuxiliary Power Outlet Ð
Console
IGN 1 Ignition Relay
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
IGN EInstrument Panel Cluster, Air
Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
PCM BPowertrain Control Module,
Fuel Pump
F/PMP Fuel Pump (Relay)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control SystemFuses Usage
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
02B Oxygen Sensors
SIRSupplemental In¯atable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller Ignition
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
DRL Daytime Running Lamps
IPC/DICInstrument Panel
Cluster/Driver Information
Center
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
5-116
Page 500 of 556
ApplicationCapacities
English Metric
VORTECŸ 6000 V8 (Vin N) 6.0 quarts (5.7 L)
VORTECŸ 8100 V8 (Vin G) 6.5 quarts (6.1 L)
Fuel Tank
Short Bed 26.0 gallons (98 L)
Short-Short Box Crew Cab 26.0 gallons (98 L)
Long Bed 34.0 gallons 128 L
Chassis Cab (pickup Box Delete) 34.0 gallons (128 L)
Chassis Cab 350027.0 gallons
23.0 gallons(102 L) (front)
(87 L) (rear)
Chassis Cab 3500 (California)24.0 gallons
23.0 gallons(90 L) (front)
(87 L) (rear)
Chassis Cab 3500 27.0 gallons (102 L (front)
Chassis Cab 3500 (California) 27.0 gallons (102 L) (front)
Chassis Cab 3500HD23.0 gallons
18.0 gallons(87 L) (front)
(68 L) (rear)
Chassis Cab 3500HD 23.0 gallons (87 L) (front)
Air Conditioning Refrigerant Capacity
Air Conditioning Refrigerant R-134a 1.6 lbs (0.7 kg)
5-120
Page 501 of 556
Normal Maintenance Replacement Parts
VIN Code W V T
Oil Filter* PF47 PF44 PF44
Engine Air Cleaner /Filter* A1519C² A1519C² A1519C²
PCV Valve* CV769C CV2001±C CV2001±C
Spark Plugs 41±932*41±974*
/PZTR5A15²²41±974*
/PZTR5A15²²
Fuel Filter* GF626 GF626 GF626
Wiper Blades** 15153642 15153642 15153642
Wiper Blade Type ITTA ITTA ITTA
Wiper Blade Length22 inches
(56.0 cm)22 inches
(56.0 cm)22 inches
(56.0 cm)
*ACDelco
žpart number
** GM part number
***Denso part number
²A1518C high-capacity air cleaner ®lter may be substituted.
²²NGK part number
5-121
Page 502 of 556
VIN Code U N G
Oil Filter* PF44 PF44 PF454
Engine Air Cleaner /Filter* A1518C A1518C A1518C
Passenger Compartment
Air Filter Kit**52485513 52485513 52485513
PCV Valve* CV2001±C CV2001±C Ð
Spark Plugs41±974*
/PZTR5A15²²41±974*
/PZTR5A15²²PTJ14R15***²²
Fuel Filter* GF626 GF626 GF626
Wiper Blades** 15153642 15153642 15153642
Wiper Blade Type ITTA ITTA ITTA
Wiper Blade Length22 inches
(56.0 cm)22 inches
(56.0 cm)22 inches
(56.0 cm)
*ACDelco
žpart number
** GM part number
***Denso part number
²A1518C high-capacity air cleaner ®lter may be substituted.
²²NGK part number
5-122