trailer CHEVROLET ASTRO 2002 Owner's Manual

4-42 Trailer Wiring Harness
If you have the optional trailering package, your vehicle
will have an eight
-wire harness, including the center
high
-mounted stoplamp battery feed wire. The harness
is stored on the passenger's side of the vehicle near the
rear wheel well. This harness has a 30 amp battery
feed wire and no connector, and should be wired by
a qualified electrical technician. After choosing an
aftermarket trailer mating connector pair, have the
technician attach one connector to the eight
-wire trailer
harness and the other connector to the wiring harness on
the trailer. Be sure the wiring harness on the trailer is
taped or strapped to the trailer's frame rail and leave it
loose enough so the wiring doesn't bend or break, but
not so loose that it drags on the ground. The eight
-wire
harness must be routed out of your vehicle between the
rear door and the floor, with enough of the harness left
on both sides so that the trailer or the body won't pull it.
If you do not have the optional trailering package, your
vehicle will still have a trailering harness. The harness
is located near the passenger's side rear wheel well.
It consists of six wires that may be used by
after
-market trailer hitch installers.The technician can use the following color code chart
when connecting the wiring harness to your trailer.

Brown: Rear lamps.

Yellow: Left stoplamp and turn signal.

Dark Green: Right stoplamp and turn signal.

White (Heavy Gage): Ground.

Light Green: Back
-up lamps.

White (Light Gage): Center High
-Mounted
Stoplamp.

Blue: Auxiliary circuit (eight
-wire harness only).

Orange: Fused auxiliary (eight
-wire harness only).
Store the harness in its original place. Wrap the
harness together and tie it neatly so it won't
be damaged.

5-9 If No Steam Is Coming From Your Engine
If you get an engine overheat warning but see or hear no
steam, the problem may not be too serious. Sometimes
the engine can get a little too hot when you:

Climb a long hill on a hot day.

Stop after high
-speed driving.

Idle for long periods in traffic.

Tow a trailer. See ªDriving on Gradesº in the Index.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. If you have an air conditioner and it's on, turn it off.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving
-- AUTOMATIC OVERDRIVE (
)
or DRIVE (D).If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for about
10 minutes. If the warning doesn't come back on,
you can drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there's still no sign of steam, push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you're parked. If you still have the warning, turn off
the engine and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.

5-17
Engine Fan Noise
This vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not fully engaged. This
improves fuel economy and reduces fan noise. Under
heavy vehicle loading, trailer towing and/or high outside
temperatures, the fan speed increases when the clutch
engages. So you may hear an increase in fan noise.
This is normal and should not be mistaken as the
transmission slipping or making extra shifts. It is merely
the cooling system functioning properly. The fan will
slow down when additional cooling is not required and
the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch disengages.
If a Tire Goes Flat
It's unusual for a tire to ªblow outº while you're driving,
especially if you maintain your tires properly. If air goes
out of a tire, it's much more likely to leak out slowly.
But if you should ever have a ªblowout,º here are a few
tips about what to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off
the accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you'd use in a
skid. In any rear blowout, remove your foot from the
accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop
-- well off the road if possible.
If a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.

6-15
As in the chart shown previously, SAE 5W-30 is best for
your vehicle. However, you can use SAE 10W
-30 if it's
going to be 0F (
-18C) or above. These numbers on
an oil container show its viscosity, or thickness. Do not
use other viscosity oils, such as SAE 20W
-50.
NOTICE:
Use only engine oil with the American
Petroleum Institute Certified For Gasoline
Engines starburst symbol. Failure to use the
recommended oil can result in engine damage
not covered by your warranty.
GM Goodwrench oil meets all the requirements for
your vehicle.
If you are in an area where the temperature falls below
-20F (-29C), consider using either an SAE 5W-30
synthetic oil or an SAE 0W
-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely low temperatures.
Engine Oil Additives
Don't add anything to your oil. The recommended oils
with the starburst symbol are all you will need for good
performance and engine protection.
When to Change Engine Oil
If any one of these is true for you, use the short trip/city
maintenance schedule:

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.

The vehicle is used for delivery service, police, taxi
or other commercial application.
Driving under these conditions causes engine oil to
break down sooner. If any one of these is true for your
vehicle, then you need to change your oil and filter
every 3,000 miles (5 000 km) or 3 months
-- whichever
occurs first.
If none of them is true, use the long trip/highway
maintenance schedule. Change the oil and filter every
7,500 miles (12 500 km) or 12 months
-- whichever
occurs first. Driving a vehicle with a fully warmed
engine under highway conditions will cause engine oil
to break down slower.

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.