2003 GMC SONOMA fuel

84,000 Miles (140 000 km)
❑Change engine oil andlter (or every 3 months,
whichever occursrst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occursrst).(See footnote #.)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote +.)
87,000 Miles (145 000 km)
❑Change engine oil andlter (or every 3 months,
whichever occursrst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occursrst).(See footnote #.)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
90,000 Miles (150 000 km)
❑Change engine oil andlter (or every 3 months,
whichever occursrst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occursrst).(See footnote #.)❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occursrst).
❑Change automatic transmissionuid andlter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C)
or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change theuid andlter every 50,000 miles
(83 000 km).
❑Replace fuellter.An Emission Control Service.
(See footnote†.)
❑Replace engine air cleanerlter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote +.)
6-16
2003 - Sonoma OM

30,000 Miles (50 000 km)
❑Change engine oil andlter (or every 12 months,
whichever occursrst).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occursrst).(See footnote #.)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occursrst).
❑Change automatic transmissionuid andlter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C)
or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change theuid andlter every 50,000 miles
(83 000 km).❑Rotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote +.)
❑4.3L V6 Engine Only: Replace fuellter.An Emission
Control Service. (See footnote†.)
❑Replace engine air cleanerlter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service.
37,500 Miles (62 500 km)
❑Change engine oil andlter (or every 12 months,
whichever occursrst).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occursrst).(See footnote #.)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote +.)
6-20
2003 - Sonoma OM

60,000 Miles (100 000 km)
❑Change engine oil andlter (or every 12 months,
whichever occursrst).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occursrst).(See footnote #.)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occursrst).
❑Change automatic transmissionuid andlter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C)
or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
conditions, change theuid andlter every 50,000 miles
(83 000 km).❑Rotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote +.)
❑4.3L V6 Engine Only: Replace fuellter.An Emission
Control Service. (See footnote†.)
❑Replace engine air cleanerlter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service.
67,500 Miles (112 500 km)
❑Change engine oil andlter (or every 12 months,
whichever occursrst).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occursrst).(See footnote #.)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote +.)
6-22
2003 - Sonoma OM

90,000 Miles (150 000 km)
❑Change engine oil andlter (or every 12 months,
whichever occursrst).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occursrst).(See footnote #.)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occursrst).
❑Change automatic transmissionuid andlter if the
vehicle is mainly driven under one or more of these
conditions:
In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C)
or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.If you do not use your vehicle under any of these
conditions, change theuid andlter every 50,000 miles
(83 000 km).
❑Replace fuellter.An Emission Control Service.
(See footnote†.)
❑Replace engine air cleanerlter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote +.)
97,500 Miles (162 500 km)
❑Change engine oil andlter (or every 12 months,
whichever occursrst).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occursrst).(See footnote #.)
❑Check rear/front axleuid level and adduid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-60for proper rotation pattern and additional
information.(See footnote +.)
6-24
2003 - Sonoma OM

Part B: Owner Checks and Services
Listed in this part are owner checks and services
which should be performed at the intervals specied to
help ensure the safety, dependability and emission
control performance of your vehicle.
Be sure any necessary repairs are completed at once.
Whenever anyuids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
in Part D.
At Each Fuel Fill
It is important for you or a service station attendant to
perform these underhood checks at each fuelll.
Engine Oil Level Check
Check the engine oil level and add the proper oil if
necessary. SeeEngine Oil on page 5-13for further
details.
Engine Coolant Level Check
Check the engine coolant level and add DEX-COOL®
coolant mixture if necessary. SeeEngine Coolant
on page 5-25for further details.
Windshield Washer Fluid Level Check
Check the windshield washeruid level in the windshield
washer tank and add the properuid if necessary. See
Windshield Washer Fluid on page 5-38for further details.
At Least Once a Month
Tire Inflation Check
Make sure tires are inated to the correct pressures.
Don’t forget to check your spare tire. SeeTires on
page 5-58for further details.
Cassette Tape Player Service
Clean cassette tape player. Cleaning should be done
every 50 hours of tape play. SeeAudio System(s)
on page 3-36for further details.
At Least Twice a Year
Restraint System Check
Make sure the safety belt reminder light and all your belts,
buckles, latch plates, retractors and anchorages are
working properly. Look for any other loose or damaged
safety belt system parts. If you see anything that might
keep a safety belt system from doing its job, have it
repaired. Have any torn or frayed safety belts replaced.
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2003 - Sonoma OM

At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specied in Part D.
Body Lubrication Service
Lubricate all body door and fuel door hinges, latches
and locks, including the glove box and console
doors, the body hood, secondary latch, pivots, spring
anchor, release pawl and any moving seat hardware.
Lubricate the hood safety lever pivot and prop rod pivot.
Part D tells you what to use. More frequent lubrication
may be required when exposed to a corrosive
environment.
Starter Switch Check
{CAUTION:
When you are doing this check, the vehicle
could move suddenly. If it does, you or others
could be injured. Follow the steps below.
1. Before you start, be sure you have enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular
brake. SeeParking Brake on page 2-32if
necessary.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only
in PARK (P) or NEUTRAL (N). If the starter works in
any other position, your vehicle needs service.
On manual transmission vehicles, put the shift lever
in NEUTRAL (N), push the clutch down halfway and
try to start the engine. The starter should work only
when the clutch is pushed down all the way to the
oor. If the starter works when the clutch isn’t pushed
all the way down, your vehicle needs service.
6-28
2003 - Sonoma OM

Part C: Periodic Maintenance
Inspections
Listed in this part are inspections and services which
should be performed at least twice a year (for instance,
each spring and fall).You should let your dealer’s
service department do these jobs. Make sure any
necessary repairs are completed at once.
Proper procedures to perform these services may be
found in a service manual. SeeService Publications
Ordering Information on page 7-9.
Steering, Suspension and Front
Drive Axle Boot and Seal Inspection
Inspect the front and rear suspension and steering
system for damaged, loose or missing parts, signs of
wear or lack of lubrication. Inspect the power steering
lines and hoses for proper hook-up, binding, leaks,
cracks, chang, etc. Clean and then inspect the drive
axle boot seals for damage, tears or leakage. Replace
seals if necessary.
Exhaust System Inspection
Inspect the complete exhaust system. Inspect the body
near the exhaust system. Look for broken, damaged,
missing or out-of-position parts as well as open seams,
holes, loose connections or other conditions which
could cause a heat build-up in theoor pan or could let
exhaust fumes into the vehicle. SeeEngine Exhaust
on page 2-37.
Fuel System Inspection
Inspect the complete fuel system for damage or leaks.
Engine Cooling System Inspection
Inspect the hoses and have them replaced if they
are cracked, swollen or deteriorated. Inspect all pipes,
ttings and clamps; replace as needed. Clean the
outside of the radiator and air conditioning condenser.
To help ensure proper operation, a pressure test of
the cooling system and pressure cap is recommended
at least once a year.
6-31
2003 - Sonoma OM

Usage Fluid/Lubricant
Rear Axle
(Locking
Differential)Axle Lubricant; use only GM Part
No. U.S. 1052271, in Canada
10950849.Do not add friction
modier.
Transfer CaseDEXRON
®-III Automatic
Transmission Fluid.
Transfer Case
Shift LeverChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Rear Driveline
Center Spline
and Universal
JointsChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Constant
Velocity
Universal JointChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Clutch Pushrod
to Clutch Fork
JointChassis Lubricant (GM Part No.
U.S. 12377985, in Canada
88901242, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Usage Fluid/Lubricant
Hood Latch
Assembly,
Secondary
Latch, Pivots,
Spring
Anchor and
Release PawlLubriplate
®Lubricant Aerosol (GM
Part No. U.S. 12346293, in Canada
992723, or equivalent) or lubricant
meeting requirements of NLGI #2,
Category LB or GC-LB.
Hood and Door
Hinges, Fuel
Filler Door and
Folding SeatsMulti-Purpose Lubricant, Superlube
®
(GM Part No. U.S. 12346241, in
Canada 10953474, or equivalent).
Tailgate Handle
Pivot Points,
Hinges, Latch
Bolt and
LinkageMulti-Purpose Lubricant, Superlube
®
(GM Part No. U.S. 12346241, in
Canada 10953474, or equivalent).
Weatherstrip
ConditioningDielectric Silicone Grease (GM Part
No. U.S. 12345579, in Canada
10953014, or equivalent).
Weatherstrip
SqueaksSynthetic Grease with Teon,
Superlube
®(GM Part No. U.S.
12371287, in Canada 10953437,
or equivalent).
6-34
2003 - Sonoma OM