2002 CHEVROLET ASTRO trailer

6-22
Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every 15,000 miles
(25 000 km) if the vehicle is mainly driven under one
or more of these conditions:

In heavy city traffic where the outside temperature
regularly reaches 90F (32C) 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 fluid and filter every
50,000 miles (83 000 km).
See ªScheduled Maintenance Servicesº in the Index.
How to Check
Because this operation can be a little difficult,
you may choose to have this done at the dealership
service department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading
on the dipstick.
NOTICE:
Too much or too little fluid can damage your
transmission. Too much can mean that some of
the fluid could come out and fall on hot engine
parts or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading
if you check your transmission fluid.

6-23
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:

When outside temperatures are above 90F (32C).

At high speed for quite a while.

In heavy traffic
-- especially in hot weather.

While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which is 180F to 200F
(82C to 93C).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50F
(10C). If it's colder than 50F (10C), drive the
vehicle in THIRD (3) until the engine temperature gage
moves and then remains steady for 10 minutes.
A cold fluid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine run
at idle for five minutes if outside temperatures are
50F (10C) or more. If it's colder than 50F (10C), you may have to idle
the engine longer. Should the fluid level be low during
this cold check, you must check the fluid hot before
adding fluid. Checking the fluid hot will give you a
more accurate reading of the fluid level.
Checking the Fluid Level
Prepare your vehicle as follows:

Park your vehicle on a level place. Keep the
engine running.

With the parking brake applied, place the shift
lever in PARK (P).

With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the
shift lever in PARK (P).

Let the engine run at idle for three minutes or more.

6-68
Fuse/Circuit
BreakerUsage
1 Stop/Turn/Hazard Lamps,
Center High Mounted Stop
Lamp, Anti
-Lock Brakes
2 Radio Accy, RR Seat
Audio ControlsFuse/Circuit
BreakerUsage
3 Courtesy Lamps, Glove Box Lamp,
Dome Reading Lamps, Vanity
Mirror Lamps, Courtesy Lamps
4 Daytime Running Lamps Relay,
Instrument Panel Cluster
5 Rear Defogger
6 Cruise Module, TBC Module,
Instrument Panel Cluster,
Cruise Control Switch,
Electrochromic Mirror
7 Power Outlets, DLC,
Subwoofer Amplifier
8 Crank Circuit Fuse, Park/Neutral
Switch, Starter Enable Relay
9 License Plate Lamp, Taillamps,
Parking Lamps, Ashtray Lamp,
Panel Lights, Trailer Taillamps,
Front and Rear Sidemarker
Lamps, Door Switch Illumination,
Headlamp Switch Illumination,
Rear Seat Audio Illumination,
TBC Module

6-69
Fuse/Circuit
BreakerUsage
10 Air Bag System
11 Not Used
12 L, M1, M2 Blower Motor, Rear A/C
Relay Coil, Front Cont. Temp. Door
Motor, HI Blower Relay, Defogger
Timer Coil
13 Cigarette Lighter, Door Lock
Switches, Dutch Door Release
Module
14 Cluster Illum, HVAC Controls,
Chime Module, Radio Illumination,
Rear Heat Switch Illumination,
Rear Wiper/Washer Switch
Illumination, Rear Liftgate Switch
Illumination, Remote Cassette
Illumination, O/H Console,
TBC Illumination
15 TBC Module, Headlamp Relay
16 Front Turn Signals, Rear Turn
Signals, Trailer Turn Signals,
Back
-Up Lamps, BTSI SolenoidFuse/Circuit
BreakerUsage
17 Front Wipers, Front Washer Pump
18 VCM
-Ign 3, VCM-Brake, Cruise
Stepper Motor Signal, ATC Module
19 Instrument Panel Radio: ATC
(Main Feed), 2000 Series (Standby)
20 PRNDL/Odometer, TCC Enable
and PWM Solenoid, Shift A and
Shift B Solenoids, 3
-2 Downshift
Solenoid, Instrument Panel Cluster,
VCM Module
21 Pwr Adj Mirrors
22 Not Used
23 Rear Wiper, Rear Washer Pump
24 Not Used
A (Circuit Breaker) Power Door
Lock Relay, 6
-Way Power Seats
B (Circuit Breaker) Power Windows

6-71
Relay Usage
A/C Relay
(Rear Heat
and A/C)Rear Heat and
Air Conditioning
Upfitter
-ACCY
RelayUpfitter Accessory
Starter
Enable RelayStarter
A/C Enable Relay Air Conditioning
Headlamps Relay Headlamps
Fuel Pump Relay Fuel Pump
Fuse/Circuit
BreakerUsage
UPFITTER
-BATT Upfitter Battery Power Stud,
Trailer Wiring Harness
UPFITTER
-ACCY Upfitter Accessory Relay
Spare Not used
Spare Not used
Spare Not used
ECM
-1B Fuel Pump Relay and Motor,
VCM, Oil Pressure Switch/SenderFuse/Circuit
BreakerUsage
HORN Horn Relay and Horn
A/C COMP A/C Enable Relay and
Compressor
RR HTR/AC Rear Heater and A/C
ATC Active Transfer Case
-L Van
FRT HVAC Front Heater and A/C
ENG
-I Oxygen Sensors, Camshaft
Position Sensor, Mass Air Flow
Sensor, Evaporative Emission
Canister Vent Solenoid
IGN
-E A/C Enable Relay Coil
ECM
-I Fuel Injectors 1-6, Crankshaft
Position Sensor, VCM,
Coil Driver Module (EST),
Ignition Coil
Blank Not Used
RH HDLMP Right Headlamp
LH Headlamp Left Headlamp
Blank Not Used
Blank Not Used

Scheduled Maintenance
7-5
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 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 first).
Chassis Lubrication (or 3 months, whichever occurs
first). 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, if driving in dusty conditions.
Front Wheel Bearing Repack (2WD only) (or at each
brake relining, whichever occurs first). 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 60,000 Miles (100 000 km): Engine Accessory
Drive Belt Inspection.

Scheduled Maintenance
7-6
Short Trip/City Intervals
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 first).
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 maintenance only if 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.

Short Trip/City Scheduled Maintenance
7-11
15,000 Miles (25 000 km)

Change engine oil and filter (or every 3 months, whichever occurs first).
An Emission Control Service.

Lubricate chassis components (or every 3 months, whichever occurs first).
(See footnote #.)

Inspect engine air cleaner filter if you are driving in dusty conditions.
Replace filter if necessary.
An Emission Control Service. (See footnote
.)
Check rear/front axle fluid level and add fluid as needed. Check constant
velocity joints and axle seals for leaking.
For Two
-Wheel-Drive vehicles only: Clean and repack the front wheel
bearings (or at each brake relining, whichever occurs first).
Change automatic transmission fluid and filter if the vehicle is mainly driven
under one or more of these conditions:
± In heavy city traffic where the outside temperature regularly
reaches 90F (32C) 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 fluid
and filter every 50,000 miles (83 000 km).
ACTUAL
SERVICED BY:MILEAGE
DATE