trailer CHEVROLET ASTRO CARGO VAN 2004 2.G Owner's Guide

Relays Usage
A/C Relay
(Rear Heat
and A/C)Rear/Heat and Air Conditioning
Uptter-ACCY
RelayUptter Accessory
Starter Enable
RelayStarter
A/C Enable
RelayAir Conditioning
Headlamps
RelayHeadlamps
Fuel Pump
RelayFuel PumpFuse/Circuit
BreakerUsage
UPFITTER-
BATTUptter Battery Power Stud,
Trailer Wiring Harness
UPFITTER-
ACCYUptter Accessory Relay
Spare Not used
Spare Not used
Spare Not used
ECM-1BFuel Pump Relay and Motor,
VCM, Oil Pressure Switch/Sender
HORN Horn Relay and Horn
A/C COMPAir Conditioning Enable Relay
and Compressor
RR HTR/AC Rear Heater and Air Conditioning
ATC Active Transfer Case-L Van
FRT HVAC Front Heater and Air Conditioning
5-105

Selecting the Right Schedule
First you will need to decide which of the two schedules
is right for your vehicle. Here is how to decide which
schedule to follow:
Short Trip/City Denition
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 or use a carrier on top
of your vehicle.
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 occurs rst).
Chassis Lubrication (or 3 months, whichever occurs
rst). Drive Axle Fluid Check.
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 occurs rst). Automatic Transmission
Service (severe conditions only).
Every 30,000 Miles (50 000 km):Engine Air Cleaner
Filter Replacement. Fuel Filter Replacement.
Every 50,000 Miles (83 000 km):Automatic
Transmission Service (normal conditions).
Transfer Case Fluid Change.
Every 100,000 Miles (166 000 km):Spark Plug
Wire Inspection. Spark Plug Replacement. Positive
Crankcase Ventilation (PCV) Valve Inspection.
Every 150 000 Miles (240 000 km):Cooling System
Service (or every 60 months, whichever occurs
rst). Engine Accessory Drive Belt Inspection.
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
6-5

Long Trip/Highway Denition
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
rst). Chassis Lubrication (or 12 months, whichever
occurs rst). Drive Axle Fluid Check. 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. Engine Air Cleaner Filter Replacement.
Front Wheel Bearing Repack (two–wheel drive only)
(or at each brake relining, whichever occurs rst).Every 50,000 Miles (83 000 km):Automatic
Transmission Service (normal conditions).
Transfer Case Fluid Change.
Every 100,000 Miles (166 000 km):Spark Plug
Wire Inspection. Spark Plug Replacement. Positive
Crankcase Ventilation (PCV) Valve Inspection.
Every 150,000 Miles (240 000 km):Cooling System
Service (or every 60 months, whichever occurs
rst). Engine Accessory Drive Belt Inspection.
These intervals only summarize maintenance services.
Be sure to follow the complete scheduled maintenance
on the following pages.
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.
6-6

15,000 Miles (25 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Inspect engine air cleaner lter. If necessary,
replace the lter. If vehicle is driven in dusty/dirty
conditions, inspect lter at every engine oil change.
SeeEngine Air Cleaner/Filter on page 5-21for
more information.An Emission Control Service.
(See footnote †.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occurs rst).
❑Change automatic transmission uid and lter 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).
18,000 Miles (30 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
21,000 Miles (35 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
24,000 Miles (40 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
6-8

27,000 Miles (45 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
30,000 Miles (50 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occurs rst).
❑Replace fuel lter.An Emission Control Service.
(See footnote †.)
❑Replace engine air cleaner lter. SeeEngine Air
Cleaner/Filter on page 5-21for more information.
An Emission Control Service.❑Change automatic transmission uid and lter 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 5-71for proper rotation pattern and additional
information.(See footnote +.)
33,000 Miles (55 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
6-9

36,000 Miles (60 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
39,000 Miles (65 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
42,000 Miles (70 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
45,000 Miles (75 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occurs rst).
❑Change automatic transmission uid and lter 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.
❑Inspect engine air cleaner lter. If necessary,
replace the lter. If vehicle is driven in dusty/dirty
conditions, inspect lter at every engine oil change.
SeeEngine Air Cleaner/Filter on page 5-21for
more information.An Emission Control Service.
(See footnote †.)
If you do not use your vehicle under any of
these conditions, change the uid and lter every
50,000 miles (83 000 km).
6-10

60,000 Miles (100 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occurs rst).
❑Change automatic transmission uid and lter 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 lter.An Emission Control Service.
(See footnote †.)
❑Replace engine air cleaner lter. SeeEngine Air
Cleaner/Filter on page 5-21for more information.
An Emission Control Service.
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
63,000 Miles (105 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
66,000 Miles (110 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
6-12

69,000 Miles (115 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
72,000 Miles (120 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
75,000 Miles (125 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occurs rst).❑Change automatic transmission uid and lter 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).
❑Inspect engine air cleaner lter. If necessary,
replace the lter. If vehicle is driven in dusty/dirty
conditions, inspect lter at every engine oil change.
SeeEngine Air Cleaner/Filter on page 5-21for
more information.An Emission Control Service.
(See footnote †.)
6-13

78,000 Miles (130 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
81,000 Miles (135 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
84,000 Miles (140 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +.)
87,000 Miles (145 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
90,000 Miles (150 000 km)
❑Change engine oil and lter (or every 3 months,
whichever occurs rst).An Emission Control Service.
❑Lubricate chassis components (or every 3 months,
whichever occurs rst).(See footnote #.)
❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occurs rst).
❑Change automatic transmission uid and lter 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).
6-14

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 5-71for proper rotation pattern and additional
information.(See footnote +).
22,500 Miles (37 500 km)
❑Change engine oil and lter (or every
12 months, whichever occurs rst).
An Emission Control Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs rst).(See footnote #).
❑Rotate tires. SeeTire Inspection and Rotation on
page 5-71for proper rotation pattern and additional
information.(See footnote +).
30,000 Miles (50 000 km)
❑Change engine oil and lter (or every
12 months, whichever occurs rst).
An Emission Control Service.
❑Lubricate chassis components (or every 12 months,
whichever occurs rst).(See footnote #).❑For Two-Wheel-Drive vehicles only: Clean and
repack the front wheel bearings (or at each
brake relining, whichever occurs rst).
❑Change automatic transmission uid and lter 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 5-71for proper rotation pattern and additional
information.(See footnote +).
❑Replace fuel lter.An Emission Control Service.
(See footnote †).
❑Replace engine air cleaner lter. SeeEngine Air
Cleaner/Filter on page 5-21for more information.
An Emission Control Service.
6-17