2004 GMC SONOMA check engine

67,500 Miles (112 500 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
75,000 Miles (125 000 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Inspect engine air cleaner filter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.An
Emission Control Service. (See footnote †.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)❑Change automatic transmission fluid and filter 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 the uid and lter every 50,000 miles
(83 000 km).
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
82,500 Miles (137 500 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
6-22

90,000 Miles (150 000 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Change automatic transmission fluid and filter 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 the uid and lter every 50,000 miles
(83 000 km).
❑Replace fuel filter.An Emission Control Service. (See
footnote †.)
❑Replace engine air cleaner filter. SeeEngine Air
Cleaner/Filter on page 5-18for more information.
An Emission Control Service.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
6-23

97,500 Miles (162 500 km)
❑Change engine oil and filter (or every 12 months,
whichever occurs first).An Emission Control
Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs first).(See footnote #.)
❑Check rear/front axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-68for proper rotation pattern and additional
information.(See footnote +.)
100,000 Miles (166 000 km)
❑Inspect spark plug wires.An Emission Control
Service.
❑Replace spark plugs.An Emission Control Service.
❑If you have not used your vehicle under severe
service conditions listed previously and, therefore,
have not changed your automatic transmission fluid,
change both the fluid and filter.
❑Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
150,000 Miles (240 000 km)
❑Drain, flush and refill cooling system (or every
60 months since last service, whichever occurs first).
SeeEngine Coolant on page 5-23for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap.An Emission Control Service.
❑Inspect engine accessory drive belt.An Emission
Control Service.
6-24

Part B: Owner Checks and Services
Listed in this part are owner checks and services
which should be performed at the intervals specified to
help ensure the safety, dependability and emission
control performance of your vehicle.
Be sure any necessary repairs are completed at once.
Whenever any fluids 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 fuel ll.
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 5-23for further details.
Windshield Washer Fluid Level Check
Check the windshield washer fluid level in the windshield
washer tank and add the proper fluid if necessary.
SeeWindshield Washer Fluid on page 5-36for further
details.
At Least Once a Month
Tire Ination Check
Visually inspect your tires and make sure tires are
inflated to the correct pressures. Do not forget to check
your spare tire. SeeTires on page 5-57for 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 3-35for further details.
6-25

At Least Four Times a Year
Tailgate Lubrication Service
Lubricate tailgate latch bolt, handle assembly pivot
points, and hinges with lubricant recommended
in Part D.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified 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 inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
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 2-25if
necessary.
Do not use the accelerator pedal, and be ready to
turn off the engine immediately if it starts.
3. 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.
6-27

Automatic Transmission Shift Lock
Control System Check
{CAUTION:
When you are doing this inspection, the
vehicle could move suddenly. If the vehicle
moves, you or others could be injured.
1. Before you start, be sure you have enough room
around the vehicle. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-25if necessary.
Be ready to apply the regular brake immediately if
the vehicle begins to move.3. With the engine off, turn the key to the RUN
position, but do not start the engine. Without
applying the regular brake, try to move the shift
lever out of PARK (P) with normal effort. If the shift
lever moves out of PARK (P), your vehicle needs
service.Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK in each shift lever position.
•The key should turn to LOCK only when the
shift lever is in PARK (P).
•The key should come out only in LOCK.
6-28

Parking Brake and Automatic
Transmission Park (P) Mechanism
Check
{CAUTION:
When you are doing this check, your vehicle
could begin to move. You or others could be
injured and property could be damaged. Make
sure there is room in front of your vehicle in
case it begins to roll. Be ready to apply the
regular brake at once should the vehicle begin
to move.Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot on the regular brake, set the
parking brake.
•To check the parking brake’s holding ability: With
the engine running and transmission in
NEUTRAL (N), slowly remove foot pressure from
the regular brake pedal. Do this until the vehicle is
held by the parking brake only.
•To check the PARK (P) mechanism’s holding ability:
With the engine running, shift to PARK (P). Then
release the parking brake followed by the regular
brake.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
6-29

Throttle System Inspection
Inspect the throttle system for interference or binding,
and for damaged or missing parts. Replace parts
as needed. Replace any components that have high
effort or excessive wear. Do not lubricate accelerator
and cruise control cables.
Transfer Case and Front Axle
(Four-Wheel Drive) Inspection
Every 12 months or at engine oil change intervals,
check front axle and transfer case and add lubricant
when necessary. A fluid loss could indicate a problem;
check and have it repaired, if needed. Check vent hose at
transfer case for kinks and proper installation. More
frequent lubrication may be required on off-road use.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. Check parking
brake adjustment. You may need to have your brakes
inspected more often if your driving habits or
conditions result in frequent braking.
6-31