2003 GMC SONOMA service

Automatic Transmission Shift Lock
Control System 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. It should be parked on a level
surface.
2. Firmly apply the parking brake. SeeParking Brake
on page 2-32if 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 don’t 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.
With an automatic transmission, the key should turn
to LOCK only when the shift lever is in PARK (P).
With a manual transmission, the key should turn to
LOCK only when you press the key release button.
On all vehicles, the key should come out only in LOCK.
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2003 - Sonoma OM

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 toush any
corrosive materials from the underbody. Take care to
clean thoroughly any areas where mud and other debris
can collect.
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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.
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2003 - Sonoma OM

Part E: Maintenance Record
After the scheduled services are performed, record the date, odometer reading and who performed the service and
any additional information from“Owner Checks and Services”or“Periodic Maintenance”on the following record
pages. Also, you should retain all maintenance receipts.
Maintenance Record
DateOdometer
ReadingServiced By Maintenance Record
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Maintenance Record (cont’d)
DateOdometer
ReadingServiced By Maintenance Record
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Maintenance Record (cont’d)
DateOdometer
ReadingServiced By Maintenance Record
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Maintenance Record (cont’d)
DateOdometer
ReadingServiced By Maintenance Record
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2003 - Sonoma OM

Customer Assistance Information......................7-2
Customer Satisfaction Procedure......................7-2
Online Owner Center......................................7-3
Customer Assistance for Text Telephone
(TTY) Users...............................................7-3
Customer Assistance Offices............................7-4
GM Mobility Program for Persons with
Disabilities..................................................7-5
Roadside Assistance Program..........................7-5
Courtesy Transportation...................................7-7Reporting Safety Defects..................................7-8
Reporting Safety Defects to the United States
Government...............................................7-8
Reporting Safety Defects to the Canadian
Government...............................................7-9
Reporting Safety Defects to General Motors.......7-9
Service Publications Ordering Information...........7-9
Section 7 Customer Assistance Information
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2003 - Sonoma OM