2002 GMC SONOMA air condition

6-63
Finish Damage
Any stone chips, fractures or deep scratches in the finish
should be repaired right away. Bare metal will corrode
quickly and may develop into a major repair expense.
Minor chips and scratches can be repaired with touch
-up
materials available from your dealer or other service
outlets. Larger areas of finish 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, 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.

6-71
Name Usage
B/U LP Back
-Up Lamps
A/C Air Conditioning
W/W PMP Not Used
HORN Horn
IGN B Column Feed, IGN 2, 3, 4
RAP Retained Accessory Power
LD LEV Not Used
OXYSEN Oxygen Sensor
IGN E Engine
MIR/LKS Mirrors, Door Locks
FOG LP Fog Lamps
IGN A Starting and Charging IGN 1
STUD #2 Accessory Feeds, Electric Brake
PARKLP Parking Lamps
LR PRK Left Rear Parking LampsName Usage
IGN C Starter Solenoid,
Fuel Pump, PRNDL
HTDSEAT Heated Seat
HVAC HVAC System
TRCHMSL Not Used
RRDFOG Not Used
TBC Truck Body Computer
CRANK Clutch Switch, NSBU Switch
HAZLP Hazard Lamps
VECHMSL Vehicle Center High
-Mounted
Stoplamp
HTDMIR Heated Outside Mirrors
ATC Transfer Case (Four
-Wheel Drive)
STOPLP Stoplamps
RR W/W Not Used

6-73
Automatic Transmission
Drain and Refill 5.0 quarts (4.7 L). . . . . . . . . . . . . .
Differential Fluid
Rear Axle 4.0 pints (1.9 L). . . . . . . . . . . . . . . . . . .
Front Axle 2.6 pints (1.2 L). . . . . . . . . . . . . . . . . . .
All capacities are approximate. After refill, the level
must be checked.
All capacities are approximate. When adding, be sure to
fill to the appropriate level or as recommended in this
manual. See ªRecommended Fluids and Lubricantsº in
the Index.
ªVORTECº 2200 L4 (VIN Code 5)
Engine Specifications
Type L4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Firing Order 1
-3-4-2 . . . . . . . . . . . . . . . . . . . . . . . . . .
Spark Plug Gap 0.040 inches (1.01 mm). . . . . . . . . .
ªVORTECº 4300 V6 (VIN Code W)
Engine Specifications
Type V6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Firing Order 1
-6-5-4-3-2 . . . . . . . . . . . . . . . . . . . . . .
Spark Plug Gap 0.060 inches (1.52 mm). . . . . . . . . .
Air Conditioning
Refrigerant Capacity
If you do your own service work, you'll need the proper
service manual. See ªDoing Your Own Service Workº in
the Index for additional information. It is recommended
that service work on your air conditioning system be
performed by a qualified technician.
Air Conditioning
Refrigerant R134a 1.8 lbs (.79 kg). . . . . . . . . . . .
Use Refrigerant Oil, R134a Systems

7-2
Have you purchased the GM Protection Plan? The Plan
supplements your new vehicle warranties. See your
Warranty and Owner Assistance booklet or your dealer
for details.
Introduction
Your Vehicle and the Environment
Proper vehicle maintenance not only helps to keep your
vehicle in good working condition, but also helps the
environment. All recommended maintenance procedures
are important. Improper vehicle maintenance can even
affect the quality of the air we breathe. Improper fluid
levels or the wrong tire inflation can increase the level
of emissions from your vehicle. To help protect our
environment, and to keep your vehicle in good
condition, please maintain your vehicle properly.
Maintenance Requirements
Maintenance intervals, checks, inspections and
recommended fluids and lubricants as prescribed in this
manual are necessary to keep your vehicle in good
working condition. Any damage caused by failure to
follow recommended maintenance may not be covered
by warranty.

7-3 How This Section is Organized
This maintenance schedule is divided into five parts:
ªPart A: Scheduled Maintenance Servicesº explains
what to have done and how often. Some of these
services can be complex, so unless you are technically
qualified and have the necessary equipment, you should
let your dealer's service department or another qualified
service center do these jobs.
CAUTION:
Performing maintenance work on a vehicle can
be dangerous. In trying to do some jobs, you can
be seriously injured. Do your own maintenance
work only if you have the required know
-how
and the proper tools and equipment for the job.
If you have any doubt, have a qualified
technician do the work.
If you want to get the service information, see ªService
and Owner Publicationsº in the Index.ªPart B: Owner Checks and Servicesº tells you
what should be checked and when. It also explains
what you can easily do to help keep your vehicle in
good condition.
ªPart C: Periodic Maintenance Inspectionsº explains
important inspections that your dealer's service
department or another qualified service center
should perform.
ªPart D: Recommended Fluids and Lubricantsº lists
some recommended products necessary to help keep
your vehicle properly maintained. These products, or
their equivalents, should be used whether you do the
work yourself or have it done.
ªPart E: Maintenance Recordº is a place for
you to record and keep track of the maintenance
performed on your vehicle. Keep your maintenance
receipts. They may be needed to qualify your vehicle for
warranty repairs.

7-4
Part A: Scheduled Maintenance
Services
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 need more
frequent checks and replacements. So please read the
following and note how you drive. If you have any
questions on how to keep your vehicle in good
condition, see your 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
Certification/Tire label. See ªLoading Your Vehicleº
in the Index.

are driven on reasonable road surfaces within legal
driving limits.

are driven off
-road in the recommended manner. See
ªOff
-Road Driving With Your Four-Wheel-Drive
Vehicleº in the Index.

use the recommended fuel. See ªFuelº 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:

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).

Your vehicle has the 2200 L4 (Code 5) flexible
fuel engine and you have used ethanol fuel
(85% Ethanol/E
-85).

You frequently tow a trailer.

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
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 Service.
Every 6,000 Miles (10 000 km): Tire Rotation.
Every 15,000 Miles (25 000 km): Engine Air Cleaner
Filter Inspection, if driving in dusty conditions. Front
Wheel Bearing Repack (2WD only) (or at each brake
relining, whichever occurs first). Automatic
Transmission Service (severe conditions only).
Every 30,000 Miles (50 000 km): Engine Air
Cleaner Filter Replacement. Fuel Filter Replacement
(4.3L V6 engine only).
Every 50,000 Miles (83 000 km): Automatic
Transmission Service (normal conditions).
Every 60,000 Miles (100 000 km): Engine Accessory
Drive Belt Inspection.
(Continued)

Scheduled Maintenance
7-7
Long Trip/Highway Intervals
Every 7,500 Miles (12 500 km): Engine Oil and Filter
Change (or every 12 months, whichever occurs first).
Chassis Lubrication (or every 12 months, whichever
occurs first). Drive Axle Service. Tire Rotation.
Every 15,000 Miles (25 000 km): Automatic
Transmission Service (severe conditions only).
Every 30,000 Miles (50 000 km): Fuel Filter
Replacement (4.3L V6 engine only). Engine Air
Cleaner Filter Replacement. Front Wheel Bearing
Repack (2WD only) (or at each brake relining,
whichever occurs first).
Every 50,000 Miles (83 000 km): Automatic
Transmission Service (normal conditions).
Long Trip/Highway Intervals
Every 60,000 Miles (100 000 km): Engine Accessory
Drive Belt Inspection.
Every 90,000 Miles (150 000 km): Fuel Filter
Replacement (2200 L4 engine only).
Every 100,000 Miles (166 000 km): Spark Plug Wire
Inspection. Spark Plug Replacement. 4.3L V6 Engine
Only: 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.