2003 CHEVROLET ASTRO Owners Manual

Underhood Fuse Block
The underhood fuse block is located toward the rear
of the engine compartment on the driver’s side of
the vehicle.
Lift the hood and open the cover to gain access to this
fuse block.
A fuse puller is included in the underhood fuse block.
You will also find spare fuses.
Feed
AUX B
AUX A
Usage
Upfitter Battery Feed
Upfitter Accessory Feed
5-96

Usage
Rear/Heat and Air Conditioning
Relays
AIC Relay
(Rear Heat
and AIC)
Relay
Relay
A/C Enable
Relay
Upfitter-ACCY
Upfitter Accessory
Starter Enable Starter
Headlamps Relay
Fuel Pump
Relay Air
Conditioning
Headlamps
Fuel Pump
FuselCircuit
Usage
UPFITTER- Upfitter Battery Power Stud,
BATT Trailer Wiring Harness
UPFITTER- Upfitter Accessory Relay
ACCY
Spare Not used
Spare Not used
Breaker FuselCircuit
Breaker
Spare
ECM-1 B
HORN
AIC COMP
RR HTR/AC ATC
FRT HVAC
ENG-I
IGN-E
ECM-I
Blank
RH HDLMP
LH Headlamp
Blank
Blank
Usage
Not used
Fuel Pump Relay and Motor, VCM,
Oil Pressure Switch/Sender
Horn Relay and Horn
Air Conditioning Enable Relay and
Compressor
Rear Heater and Air Conditioning
Active Transfer Case-L Van
Front Heater and Air Conditioning
Oxygen Sensors, Camshaft Position
Sensor, Mass Air Flow Sensor,
Evaporative Emission Canister
Vent Solenoid
Air Conditioning Enable Relay Coil
Fuel Injectors
1-6, Crankshaft
Position Sensot, VCM, Coil Driver
Module (EST), Ignition Coil
Not Used
Right Headlamp
Left Headlamp
Not Used
Not Used
5-97

Fuse/Circuit Usage
Breaker
DIODE-I Air Conditioning
Blank Not Used
Blank
Not Used
Blank Not Used
LIGHTING Courtesy Fuse, Power Adjust
Mirrors Fuse, Truck Body Control
Battery Fuse
Power Accessory Circuit Breaker,
Stop/Hazard Fuse, Auxiliary Power
Fuse, Cigarette Lighter Fuse, Radio
Battery Fuse
BATT
Fuse/Circuit
Breaker
IGN A
IGN
B
ABS
Blank RAP
HTD MIRI
RR DEFOG
Usage
Starter Relay, Ignition Switch
Ignition Switch
Electronic Brake Control Module
Not Used Radio Accessory, Power Windows
Rear Window Defogger,
Climate Control Head
5-98

Capacities and Specifications
Please refer to Part D: Recommended Nuids and Lubricants on page 6-32 for more information. See refrigerant
charge label under the hood for charge capacity information and requirements.
Engine Specifications
“Vortec” 4300 V6 MFI* 1-6-5-4-3-2
I *Micro Fuel IniectionTire Pressures - See Loadina Your Vehicle on mae 4-29. I
Capacities and Specifications
I Capacities I
Fuel Tank I 27.0 gallons I 101.8 L
Transmission Fluid (Drain and Refill) 4.7 L 5.0 quarts
5-99

Capacities and Specifications (cont’d)
I Capacities 1
Application English
Differential
Front Axle
Rear Axle
Fluid
2.6 pints
3.5 pints
Refrigerant Type 134a
Front A/C
Front and Rear A/C
2.25 Ibs.
3.0 Ibs.
Metric
1.2 L
1.7 L
1.02 kg
1.36 kg
1
Ail capacities are approximate. When adding, be sure to fill to the appropriate level, as recommended in this
manual. recheck the fluid level after filling. See
Parf D: Recommended Fluids and Lubricants on page 6-32 for
more information.
5-1 00

Normal Maintenance Replacement Parts
Replacement part numbers listed in this section are based on the latest information available at the time of printing,
and are subject to change.
If a part listed in this manual is not the same as the part used in your vehicle when it
was built, or
if you have any questions, please contact your GM truck dealer.
Part Number
I Engine Oil Filter
PF47*
Positive Crankcase Ventilation (PCV) Valve CV769C*
I Spark Plugs
41 -932*
I Fuel Filter
GF481*
Wiper Blades (Front)
Type
Length Trico 221 101 58
18 inches (45.7 cm)
Wiper Blades (Rear)
Type
Length Trico 22 1 54396
14 inches (35.5 cm)
5-1 01

Section 6 Maintenance Schedule
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
................................... 6.26 At
Least Once a Year
................................... 6-27
Part C: Periodic Maintenance inspections
......... 6.30
Steering. Suspension and Front Drive Axle
Boot and Seal Inspection
............................ 6.30
Exhaust System Inspection
............................ 6.30
Fuel System Inspection
.................................. 6.30
Engine Cooling System Inspection
................... 6.30
Throttle System Inspection
............................ -6-31
Transfer Case and Front Axle
(All-Wheel Drive) Inspection
....................... -6-31
Brake System Inspection
................................ 6.31
Part D: Recommended Fluids
and Lubricants
.......................................... 6.32
Part E: Maintenance Record
........................... 6.34
6-
1