Page 317 of 411

6-50 Wheel Replacement
Replace any wheel that is bent, cracked, or badly rusted
or corroded. If wheel nuts keep coming loose, the wheel,
wheel bolts and wheel nuts should be replaced. If the
wheel leaks air, replace it (except some aluminum
wheels, which can sometimes be repaired). See your
dealer if any of these conditions exist.
Your dealer will know the kind of wheel you need.
Each new wheel should have the same load
-carrying
capacity, diameter, width, offset and be mounted the
same way as the one it replaces.
If you need to replace any of your wheels, wheel bolts
or wheel nuts, replace them only with new GM original
equipment parts. This way, you will be sure to have the
right wheel, wheel bolts and wheel nuts for your vehicle.
CAUTION:
Using the wrong replacement wheels, wheel bolts
or wheel nuts on your vehicle can be dangerous. It
could affect the braking and handling of your
vehicle, make your tires lose air and make you lose
control. You could have a collision in which you or
others could be injured. Always use the correct
wheel, wheel bolts and wheel nuts for replacement.
NOTICE:
The wrong wheel can also cause problems with
bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper
height, vehicle ground clearance and tire or tire
chain clearance to the body and chassis.
Page 332 of 411
6-65
POSITION NAME CIRCUITS PROTECTED
14. ILLUM Instrument Panel Cluster, HVAC Controls, RR HVAC Controls,
Instrument Panel Switches, Radio Illumination,
Door Switch Illumination
15. DRL Daytime Running Lamp Relay
16. TURN B/U
Front Turn, RR Turn, Back
-up Lamps, BTSI Solenoid
17.
RADIO
-1Radio (Ign, Accy), Upfitter Provision Relay
18. BRAKE 4WAL PCM, ABS, Cruise Control
19.
RADIO
-BRadio (Battery), Power Antenna
20. TRANS PRNDL, Automatic Transmission
21. SECURITY Passlock
22. RR DEFOG Rear Window Defog
23. NOT USED Not Used
24. RR HVAC RR HVAC Controls, HIGH, MED, LOW Relays
A. PWR ACCY
Power Door Lock, Six
-Way Power Seat, Keyless Entry
Illumination Module
B. PWR WDO Power Windows
Page 333 of 411
6-66 Engine Compartment Fuse Block
The fuse block is in the engine compartment on the
driver's side of the vehicle.
NAME CIRCUITS PROTECTED
SPARE Spare Fuse
A.I.R. Air Pump
BLOWER Front Blower Motor
ABS Electronic Brake Control Module
IGN B Ignition Switch
IGN A Starter Relay, Ignition Switch
BATT Instrument Panel Fuse Block
LIGHTING Instrument Panel Fuse Block,
Headlamp Switch
RH
-HDLP Right-hand Headlamp
(Export only)
LH
-HDLP Left-hand Headlamp
(Export only)
RH
-HIBM Right-hand High-beam Headlamp
(Export only)
LH
-HIBM Left-hand High-beam Headlamp
(Export only)
Page 344 of 411

Scheduled Maintenance
7-5
Short Trip/City Definition
Follow the Short Trip/City Scheduled Maintenance if
any one of these conditions is true for your vehicle:
Most trips are less than 5 miles (8 km). This is
particularly important when outside temperatures
are below freezing.
Most trips include extensive idling (such as frequent
driving in stop
-and-go traffic).
You frequently tow a trailer or use a carrier on top
of your vehicle.
If the vehicle is used for delivery service, police,
taxi or other commercial application.
One of the reasons you should follow this schedule
if you operate your vehicle under any of these
conditions is that these conditions cause engine oil
to break down sooner.
Short Trip/City Intervals
At 3,000 Miles (5 000 km): Drive Axle Service
(2500 and 3500 Series with locking differential only).
Every 3,000 Miles (5 000 km): Engine Oil and Filter
Change (or 3 months, whichever occurs first). Chassis
Lubrication (or 3 months, whichever occurs first).
Drive Axle Fluid Check.
Every 6,000 Miles (10 000 km): Tire Rotation.
Every 15,000 Miles (25 000 km): Diesel Engine Only:
Engine Air Cleaner Filter Inspection, if driving in
dusty conditions. Drive Axle Service When Towing
(2500 and 3500 Series only). Gasoline Engine Only:
Noise Shields Inspection (GVWR above 10,000 lbs.
only). Diesel Engine Only: Shields and Underhood
Insulation Inspection. Diesel Engine Only:
Thermostatically Controlled Engine Cooling Fan
Check (or every 12 months, whichever occurs first).
Diesel Engine Only: Air Intake System Inspection.
Front Wheel Bearing Repack (or at each brake
relining, whichever occurs first).
Page 347 of 411

Scheduled Maintenance
7-8
Long Trip/Highway Intervals
Every 30,000 Miles (50 000 km): Fuel Filter
Replacement. Diesel Engine Only: Engine Air
Cleaner Filter Replacement. Front Wheel Bearing
Repack (or at each brake relining, whichever
occurs first).
Every 50,000 Miles (83 000 km): Automatic
Transmission Service (vehicles over 8600 GVWR
or driven under severe conditions or equipped with
diesel engine).
Every 60,000 Miles (100 000 km): Engine Accessory
Drive Belt Inspection. If Equipped: Exhaust Gas
Recirculation System Inspection. Gasoline Engine
Only: Evaporative Control System Inspection. Diesel
Engine Only: Crankcase Depression Regulator Valve
(CDRV) System Check.
Long Trip/Highway Intervals
Every 100,000 Miles (166 000 km): Gasoline Engine
Only: Spark Plug Wire Inspection. Gasoline Engine
Only: Spark Plug Replacement. Gasoline Engine
Only: Automatic Transmission Service (normal
conditions). Gasoline Engine Only (Except 8.1L V8):
Positive Crankcase Ventilation (PCV)
Valve Inspection.
Every 150,000 Miles (240 000 km): Cooling System
Service (or every 60 months, whichever occurs first).
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
Page 348 of 411

Short Trip/City Scheduled Maintenance
7-9
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown at 150,000 miles
(240 000 km) should be repeated at the same
interval after 150,000 miles (240 000 km) for the
life of this vehicle.
See ªOwner Checks and Servicesº and ªPeriodic
Maintenance Inspectionsº following.Footnotes
The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle's useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.
# Lubricate the front suspension, kingpin bushings,
steering linkage and rear driveline center splines.
+ A good time to check your brakes is during tire
rotation. See ªBrake System Inspectionº under
ªPeriodic Maintenance Inspectionsº in Part C of
this schedule.
Page 351 of 411

Short Trip/City Scheduled Maintenance
7-12
15,000 Miles (25 000 km)
Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.
Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)
Diesel Engine Only: Inspect engine air cleaner filter if you are driving in
dusty conditions. Replace filter if necessary.
An Emission Control Service. (See footnote .)
Gasoline Engine Only: See ªEngine Air Cleaner Filter Restriction Indicator
Checkº in the Index.
Check axle fluid level and add fluid as needed. 2500 and 3500 Series Only:
If driving in dusty areas or when towing a trailer, drain fluid and refill every
15,000 miles (25 000 km).
Clean and repack the front wheel bearings (or at each brake relining,
whichever occurs first).
Vehicles With GVWR Above 10,000 lbs. or Equipped with Diesel Engine
Only: Inspect shields for damage or looseness. Adjust or replace as required.
This is a Noise Emission Control Service. Applicable only to vehicles sold
in the United States.ACTUAL
SERVICED BY:MILEAGE
DATE
Page 354 of 411
Short Trip/City Scheduled Maintenance
7-15
27,000 Miles (45 000 km)
Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.
Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)
Check axle fluid level and add fluid as needed.
30,000 Miles (50 000 km)
Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.
Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)
Check axle fluid level and add fluid as needed. 2500 and 3500 Series Only:
If driving in dusty areas or when towing a trailer, drain fluid and refill every
15,000 miles (25 000 km).
Clean and repack the front wheel bearings (or at each brake relining,
whichever occurs first).
Replace fuel filter. An Emission Control Service. (See footnote .)
(Continued)
ACTUAL
SERVICED BY:MILEAGE
DATE
ACTUAL
SERVICED BY:MILEAGE
DATE