2003 GMC SONOMA radiator cap

93,000 Miles (155 000 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 **.)
96,000 Miles (160 000 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 +.)
99,000 Miles (165 000 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 **.)
100,000 Miles (166 000 km)
❑Inspect spark plug wires.An Emission Control
Service.
❑Replace spark plugs.An Emission Control Service.
❑If you haven’t used your vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transmissionuid, change
both theuid andlter.
Manual transmissionuid doesn’t require change.
❑4.3L V6 Engine Only: Inspect Positive Crankcase
Ventilation (PCV) valve.An Emission Control
Service.
150,000 Miles (240 000 km)
❑Drain,ush and rell cooling system (or every
60 months since last service, whichever occursrst).
SeeEngine Coolant on page 5-25for what to use.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test cooling system and
pressure cap.An Emission Control Service.
❑Inspect engine accessory drive belt.An Emission
Control Service.
6-17
2003 - Sonoma OM

100,000 Miles (166 000 km)
❑Inspect spark plug wires.An Emission Control
Service.
❑Replace spark plugs.An Emission Control Service.
❑If you haven’t used your vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transmissionuid, change
both theuid andlter. Manual transmission
uid doesn’t require change.
❑4.3L V6 Engine Only: Inspect Positive Crankcase
Ventilation (PCV) valve.An Emission Control
Service.
150,000 Miles (240 000 km)
❑Drain,ush and rell cooling system (or every
60 months since last service, whichever occursrst).
SeeEngine Coolant on page 5-25for 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.
6-25
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

Parking
Brake........................................................2-32
Over Things That Burn.................................2-36
Parking Brake and Automatic Transmission
Park (P) Mechanism Check...........................6-30
Parking on Hills..............................................4-59
Parking Your Vehicle.......................................2-36
Part A - Scheduled Maintenance Services............ 6-4
Part B - Owner Checks and Services................6-26
Part C - Periodic Maintenance Inspections..........6-31
PartD-Recommended Fluids and Lubricants....6-33
PartE-Maintenance Record...........................6-35
Passing.................................................4-10, 4-58
Passlock
®......................................................2-19
Payload.........................................................4-48
Pickup Conversion to Chassis Cab....................4-50
Plan Ahead When Possible................................ 7-7
Playing a Cassette Tape..................................3-52
Playing a Compact Disc..................3-45, 3-54, 3-62
Playing a Specific Loaded
Compact Disc
.............................................3-63
Playing the Radio
...................3-37, 3-40, 3-47, 3-56
Power
Accessory Outlets
........................................3-15
Door Locks
.................................................. 2-9
Electrical System
.........................................5-88
Lumbar Controls
........................................... 1-5
Seat
............................................................ 1-4Power (cont.)
Steering Fluid.............................................5-37
Windows....................................................2-15
Power Steering................................................ 4-8
Programmable Automatic Door Locks.................. 2-9
Q
Questions and Answers About Safety Belts.........1-15
R
Radiator Pressure Cap....................................5-27
Radio Messages.............................3-39, 3-45, 3-52
Radios..........................................................3-36
AM-FM Radio.............................................3-37
Care of Your Cassette Tape Player................3-68
Care of Your CD Player...............................3-69
Care of Your CDs ........................................3-69
Radio with Cassette and CD.........................3-47
Radio with CD............................................3-40
Radio with Six-Disc CD................................3-56
Setting the Time for Radios with Radio
Data Systems (RDS)................................3-37
Setting the Time for Radios without Radio
Data Systems (RDS)................................3-36
Theft-Deterrent............................................3-67
Understanding Reception..............................3-67
RDS Messages..............................3-43, 3-51, 3-61
11
2003 - Sonoma OM