Page 282 of 388
Inflation -- Tire Pressure
The Certificationflire label, which is on the rear edge of
the driver’s door, shows the correct inflation pressures
for your tires when they’re cold.
“Cold” means your
vehicle has been sitting for at least three hours or driven
no more than
1 mile (1.6 km).
NOTICE:
Don’t let anyone tell you that underinflation or
overinflation is all right. It’s not. If your tires
don’t
hav.2 enough air (underinflation), you can
get the following:
Too much flexing
Too much heat
Tire overloading
0 Bad wear
Bad handling
Bad fuel economy.
NOTICE: (Continued)
NOTICE: (Continued)
If your tires have too much air (overinflation),
you can get the following:
Unusual wear
Bad handling
Rough ride
Needless damage from road hazards.
Check your tires once
a month or more. Also, check the
tire pressure
of the spare tire.
6-42
ProCarManuals.com
Page 298 of 388

Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect
on the underbody. If these are not
removed, accelerated corrosion (rust) can occur on
the underbody parts such as fuel lines, frame, floor
pan and exhaust system even though they have
corrosion protection.
At least every spring, flush these materials from
the
underbody with plain water. Clean any areas where mud
and other debris can collect. Dirt packed in closed areas
of the frame should be loosened before being flushed.
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, ringlet-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 first.
This applies only
to materials manufactured and sold by
General Motors. Bodies, body conversions or equipment
not made or sold by General Motors
are not covered.
6-58
ProCarManuals.com
Page 305 of 388
Engine Compartment Fuse Relay Center
The fuse block is on the driver’s side of the engine
compartment at the rear.
NAME
BLOWER
ABS
CIRCUITS PROTECTED
Front Blower Motor
Electronic Brake Control Module
NAME
IGN-B
IGN-A
BATT
LIGHTING
CIRCUITS PROTECTED
Ignition Switch
Starter Relay, Ignition Switch
Instrument Panel Fuse Block
Instrument Panel Fuse Block,
Headlamp Switch
RR BLOWER Rear Auxiliary Blower Motor Relays
ENG-I
AIC
SPARE
AUX A
AUX B
RH-HDLP
Heated 02 Sensors, Mass Air Flow
Sensor, EGR Valve Solenoid, Evap
Canister Purge Valve, Crankshaft
Position Sensor, Secondary Air
Injection Relay (Diesel), Water in
Fuel Sensor (Diesel), Fuel Heater
(Diesel), Glowplug Relay (Diesel),
Wastegate Solenoid (Diesel)
Air Conditioning Clutch Relay
Spare Fuses
Upfitter Provisions
Upfitter Provisions Right-hand Headlamp (Export only)
6-65
ProCarManuals.com
Page 306 of 388
NAME
RH-HIBM
ECM-I
HORN
LH-HDLP
LH-HIBM
FUEL SOL
IGN-E
ECM-B
CIRCUITS PROTECTED
Right-hand High-beam Headlamp
(Export only)
Ignition Coil, Camshaft Position
Sensor,
VCM, Fuel Injectors, Coil
Driver
Horn Relay, Underhood Lamp( s)
Left-hand Headlamp (Export
only)
Left-hand High-beam Headlamp
(Export only)
PCM,
Fuel Solenoid Driver, Engine
Shutoff Solenoid
Air Conditioning Clutch Relay
Fuel Pump Relay, VCM, PCM, Fuel
Pump and Engine Oil Pressure
Switch
Replacement Bulbs
LAMP OR BULB
Sealed Beam Headlamps
Composite Low-Beam
Headlamps
Composite High-Beam
Headlamps
Front Sidemarker Lamp
Front Parking and Turn Lamp
Rear Parking Lamp
Rear Stop and Turn Lamp
Back- up Lamp
Back-up Lamp
Rear Parking, Stop, and
Turn Lamp
CHMSL
License Plate Lamp
Underhood Lamp
Reel Lamp
Reading Lamps
Sunshade Vanity Mirror
QTY NUMBER
2 H6054
2 6052
2
2
4
2
1
1
1
6
4
9005
194
2357NA
3057
3057
3156
1156 1157
92
1
194
232
232
211-2
74
6-66
ProCarManuals.com
Page 307 of 388
Capacities and Specifications
Replacement Parts
Replacement part numbers listed in this section are based on the latest information available at the time of printing,
and are subject to change. If a part listed in this manual
is not the same as the part used in your vehicle when it was
built, or if you have any questions, please contact your
GM dealer.
These specifications are for information only.
If you have any questions, see the service manual for the chassis or
refer to the body manufacturer’s publications.
Engine Identification -- Gasoline Engines
Engine “VORTEC” 4300 “VORTEC” 5000
Type V6 V8
VIN Code w M
Fuel System CSFI~ CSFI~
*Central Sequential Fuel Injection
2Sequential
Fuel Injection
“VORTEC” 5700
V8
R
CSFI~
“VORTEC” 7400
V8
J
SFI~
Wheel Nut Torque
MODEL TORQUE
All 140 ft-lb (190 N-m)
ProCarManuals.com
Page 309 of 388
Fuel Tank Capacity (Approximate)
TYPE QUANTITY
Standard Tank 3 1 Gallons (117.33 L)
Standard Tank 33 Gallons (124.90 L)
Optional Tank* 55 Gallons (208.18 L)
** 159”, 177” Wheelbase Vehicles Only.
MODEL TYPE
Passenger and Cargo
Cab and Chassis
Cab and Chassis
Normal Maintenance Replacement Parts
Engine “VORTEC”4300 “VORTEC”5000
VIN W M
Oil Filter PF52 PF1218
Air Cleaner Filter
* A917C A917C
PCV Valve CV789C cv774c
Spark Plugs 41-932 4 1-932
Fuel Filter GF48 1 GF48 1
Radiator Cap
RC36 RC36
“VORTEC”5700
R
PF1218
A917C
cv774c 4 1-932
GF48 1
RC36
“VORTEC”7400
J
PF1218 A917C
cv774c 4 1-932
GF48
1
RC36
* Replace with AC Air Filter, Part No. A917C and for severe dusty conditions, use AC Air Filter, Part No. 1236C.
6-69
ProCarManuals.com
Page 313 of 388
Section 7 Maintenance Schedule
This section covers the maintenance required for your vehicle. Your vehicle needs these services to retain its safety,
dependability and emission control performance.
7-2
7-4
7-5
7-5
7-6
7-7 Introduction
Part
A: Scheduled Maintenance Services
Short Trip/City Definition
Short Trip/City Intervals
Long TripMighway Definition
Long TripMighway Intervals 7-8
Short Trip/City Maintenance Schedule
7-27 Long Trip/Highway Maintenance Schedule
7-38 Part
B: Owner Checks at Each Fuel Fill-up
7-42 Part C: Periodic Maintenance Inspections
7-44 Part D: Recommended Fluids
and Lubricants
7-46 Part
E: Maintenance Record
7-1
ProCarManuals.com
Page 316 of 388

Part A: Scheduled Maintenance
Servk - s
Using Your Maintenance Schedule
We at General Motors want to help you keep your vehicle
in good working condition. But we don’t know exactly
how you’ll drive it. You may drive very short distances
only a few times a week.
Or you may drive long distances
all the time in very hot, dusty weather. You may use your
vehicle
in making deliveries. Or you may drive it to work,
to do errands or
in many other ways.
Because of all the different
ways people use their
vehicles, maintenance needs
vary. You may even need
more frequent checks and replacements than you’ll find
in the schedules in this section.
So please read this
section and note how you drive. If you have any
questions
on how to keep your vehicle in good
condition, see your
GM dealer.
This part tells you the maintenance services you should
have done and when you should schedule them. If you
go to your dealer for your service needs, you’ll know
that GM-trained and supported service people will
perform the work using genuine GM
parts.
The proper fluids and lubricants to use are listed in Part D.
Make sure whoever services your vehicle uses these. All
parts should be replaced
and all necessary repairs done
before you or anyone else
drives the vehicle.
These schedules are for vehicles that:
carry passengers and cargo within recommended
limits. You will find these limits on your vehicle’s
Certificationflire label. See “Loading Your Vehicle’’
in the Index.
are driven on reasonable road surfaces within legal
driving limits.
use the recommended fuel. See “Fuel” in the Index.
Selecting the Right Schedule
First you’ll need to decide which of the two schedules is
right for your vehicle. Here’s how
to decide which
schedule to follow:
Gasoline engine vehicles
and diesel engine vehicles
have different maintenance requirements. If you have
a
diesel engine, follow a schedule designated for diesel
engine vehicles only.
See the Diesel Engine Supplement for diesel engine
maintenance schedules.
7-4
ProCarManuals.com