brake GMC SONOMA 2003 Repair Manual

Fuse Usage
20 Amplifier
21 Heating, Ventilation, Air Cooling
(Manual), Heating,Ventilation,
Air Cooling (Automatic), Heating,
Ventilation, Air Cooling Sensors
(Automatic)
22 Anti-Lock Brakes
23 Rear Wiper
24 Radio, IgnitionEngine Compartment Fuse Block
The engine compartment fuse block is located under
the hood on the driver’s side of the vehicle. SeeEngine
Compartment Overview on page 5-10for more
information on location.
Remove the cover by turning the fastener
counterclockwise. To reinstall the fuse panel cover,
push in and turn the fastener clockwise.
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Fuse Usage
TRL TRN Trailer Left Turn
TRR TRN Trailer Right Turn
TRL B/U Trailer Back Up Lamps
VEH B/U Vehicle Back Up Lamps
HDLP PWR Headlamp PowerFuse Usage
RT TURN Right Turn Signal Front
LT TURN Left Turn Signal Front
HDLP W/W Not Used
LT TRN Left Turn Signal Rear
RT TRN Right Turn Signal Rear
RR PRK Right Rear Parking Lamps
TRL PRK Trailer Park Lamps
LTHDLP Left Headlamp
RTHDLP Right Headlamp
FRPRK Front Parking Lamps
INT BAT Instrument Panel Fuse Block Feed
ENG I Engine Sensors/Solenoids, MAF,
CAM, PURGE, VENT
ECM B Engine Control Module, Fuel Pump
Module, Oil Pressure
ABS Anti-Lock Brake System
ECM I Engine Control Module Injectors
F/PUMP Fuel Pump
DRL Daytime Running Lamps
A/C Air Conditioning
HORN Horn
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Fuse Usage
W/W PMP Not Used
HORN Horn
BTSI Automatic Transmission Shift Lock
Control System
B/U LP Back Up Lamps
IGN B Column Feed,Ignition 2, 3, 4
STARTER Starter
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 Ignition 1
STUD #2 Accessory Feeds, Electric Brake
PARKLP Parking Lamps
LR PRK Left Rear Parking Lamps
LIFTGLASS Liftglass
IGN C Starter Solenoid, Fuel Pump,
PRNDL
HTDSEAT Heated SeatFuse Usage
HVAC Heating,Ventilation, Air Cooling
System
TRCHMSL Trailer Center High Mount Stop Light
RRDFOG Rear Defogger
TBC Truck Body Computer
CRANK Clutch Switch, NSBU Switch
CHMSL Center High Mounted Stoplamp
HAZLP Hazard Lamps
VECHMSL Vehicle Center High-Mounted
Stop Lamp
RR DEFOG Rear Defogger
HTDMIR Heated Mirror
ATC Transfer Case (Four-Wheel Drive)
STOPLP Stop Lamps
RR W/W Rear Window Wiper
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Maintenance Schedule......................................6-2
Introduction...................................................6-2
Your Vehicle and the Environment....................6-2
Maintenance Requirements..............................6-2
How This Section is Organized.........................6-3
Part A: Scheduled Maintenance Services...........6-4
Using Your Maintenance Schedule....................6-4
Selecting the Right Schedule...........................6-5
Short Trip/City Scheduled Maintenance..............6-7
Long Trip/Highway Scheduled Maintenance......6-18
Part B: Owner Checks and Services................6-26
At Each Fuel Fill..........................................6-26
At Least Once a Month.................................6-26
At Least Twice a Year...................................6-26At Least Four Times a Year...........................6-27
At Least Once a Year...................................6-28
Part C: Periodic Maintenance Inspections.........6-31
Steering, Suspension and Front Drive Axle
Boot and Seal Inspection............................6-31
Exhaust System Inspection............................6-31
Fuel System Inspection..................................6-31
Engine Cooling System Inspection...................6-31
Throttle System Inspection.............................6-32
Transfer Case and Front Axle (Four-Wheel
Drive) Inspection.......................................6-32
Brake System Inspection................................6-32
Part D: Recommended Fluids and Lubricants. . . .6-33
Part E: Maintenance Record...........................6-35
Section 6 Maintenance Schedule
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2003 - Sonoma OM

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:
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).
•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 occursfirst). Chassis
Lubrication (or 3 months, whichever occursfirst).
Drive Axle Service.
Every 6,000 Miles (10 000 km):Tire Rotation.
Every 15,000 Miles (25 000 km):Engine Air Cleaner
Filter Inspection. Front Wheel Bearing Repack
(two-wheel drive only) (or at each brake relining,
whichever occursfirst). 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 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.
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2003 - Sonoma OM

Every 150 000 Miles (240 000 km):Cooling System
Service (or every 60 months, whichever occurs
first). Engine Accessory Drive Belt Inspection.
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
Long Trip/Highway Definition
Follow this scheduled maintenanceonlyif none of the
conditions from the Short Trip/City Scheduled
Maintenance are true. Do not use this schedule if the
vehicle is used for trailer towing, driven in a dusty area
or used off paved roads. Use the Short Trip/City
schedule for these conditions
Driving a vehicle with a fully warmed engine under
highway conditions will cause engine oil to break down
slower.
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 12 months, whichever
occursfirst). Drive Axle Service. Tire Rotation.
Every 15,000 Miles (25 000 km):Engine Air Cleaner
Filter Inspection. 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
(two-wheel drive only) (or at each brake relining,
whichever occursfirst).
Every 50,000 Miles (83 000 km):Automatic
Transmission Service (normal conditions).
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). Engine Accessory Drive Belt Inspection.
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
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Short Trip/City Scheduled
Maintenance
The services shown in this schedule up to 100,000 miles
(166 000 km) should be repeated after 100,000 miles
(166 000 km) at the same intervals for the life of
this vehicle. The services shown at 150,000 miles
(240 000 km) should be repeated at the same interval
after 150,000 miles (240 000 km) for the life of this
vehicle.
SeePart B: Owner Checks and Services on page 6-26
andPart C: Periodic Maintenance Inspections on
page 6-31.
Footnotes
†The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to
the completion of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the
maintenance be recorded.#Lubricate the front suspension, ball joints, steering
linkage, parking brake cable guides, propshaft splines,
universal joints, constant velocity joint and brake
pedal springs.
+A good time to check your brakes is during tire
rotation. See Brake System Inspection on page 6-32.
**Drive axle service. See Part D: Recommended Fluids
and Lubricants on page 6-33 for proper lubricant to use:
•Check uid level and add uid as needed. If driving in
dusty areas or when towing a trailer, drain uid and
rell every 15,000 miles (25 000 km).
•If your vehicle has a locking differential, drain uid
and rell at rst engine oil change.
•More frequent lubrication may be required for
heavy-duty or off-road use.
3,000 Miles (5 000 km)
❑Change engine oil andfilter (or every 3 months,
whichever occursfirst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occursfirst).(See footnote #.)
❑Check rear/front axlefluid level and addfluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
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6,000 Miles (10 000 km)
❑Change engine oil andfilter (or every 3 months,
whichever occursfirst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occursfirst).(See footnote #.)
❑Check rear/front axlefluid level and addfluid 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 +.)
9,000 Miles (15 000 km)
❑Change engine oil andfilter (or every 3 months,
whichever occursfirst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occursfirst).(See footnote #.)
❑Check rear/front axlefluid level and addfluid as
needed. Check constant velocity joints and axle seals
for leaking.(See footnote **.)
12,000 Miles (20 000 km)
❑Change engine oil andfilter (or every 3 months,
whichever occursfirst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occursfirst).(See footnote #.)❑Check rear/front axlefluid level and addfluid 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 +.)
15,000 Miles (25 000 km)
❑Change engine oil andfilter (or every 3 months,
whichever occursfirst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occursfirst).(See footnote #.)
❑Inspect engine air cleanerfilter. If necessary, replace
thefilter. If vehicle is driven in dusty/dirty conditions,
inspectfilter at every engine oil change. See
Engine Air Cleaner/Filter on page 5-18for more
information.An Emission Control Service.
(See footnote†.)
❑Check rear/front axlefluid level and addfluid 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 occursfirst).
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27,000 Miles (45 000 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 **.)
30,000 Miles (50 000 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).
❑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.❑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 +.)
33,000 Miles (55 000 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 **.)
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36,000 Miles (60 000 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 +.)
39,000 Miles (65 000 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 **.)
42,000 Miles (70 000 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 +.)
45,000 Miles (75 000 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).
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