2001 GMC ENVOY Owners Manual

4-57 When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:

Start your engine;

Shift into a gear; and

Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for
more on this. Things that are especially important
in trailer operation are automatic transmission fluid
(don't overfill), engine oil, axle lubricant, belt, cooling
system and brake system. Each of these is covered in
this manual, and the Index will help you find them
quickly. If you're trailering, it's a good idea to review
these sections before you start your trip.
Check periodically to see that all hitch nuts and
bolts are tight.
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4-58 Trailer Wiring Harness
The light-duty trailer wiring is a six-wire harness
assembly. The optional heavy
-duty trailer wiring is an
eight
-wire harness assembly. The harnesses are stored
under the vehicle, along the passenger
-side frame
crossmember on two
-door vehicles or on the driver's
side corner frame rear crossmember on four
-door
vehicles. The heavy
-duty trailer wiring is fused in the
engine compartment fuse block. See ªFuses and Circuit
Breakersº in the Index. Both harnesses have no
connector and should be wired by a qualified
electrical technician. The technician can use the
following color code chart when connecting the
wiring harness to your trailer.
Dark Blue: Use for electric trailer brakes or auxiliary
wiring (eight
-wire harness only).

Red: Use for battery charging; it connects to the
starter solenoid (eight
-wire harness only).

Light Green: Back
-up lamps.

Brown: Taillamps and parking lamps.

Yellow: Left stoplamp and turn signal.

Dark Green: Right stoplamp and turn signal.

White: Ground wire.

Light Blue: Auxiliary stoplamp.
Securely attach the harness to the trailer, then tape or
strap it to your vehicle's frame rail. Be sure you leave it
loose enough so the wiring doesn't bend or break,
but not so loose that it drags on the ground. Store the
harness in its original place. Wrap the harness together
and tie it neatly so it won't be damaged.
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5-
5-1
Section 5 Problems on the Road
Here you'll find what to do about some problems that can occur on the road.
5
-2 Hazard Warning Flashers
5
-3 Other Warning Devices
5
-3 Jump Starting
5
-8 Towing Your Vehicle
5
-8 Engine Overheating
5
-10 Cooling System5
-17 Engine Fan Noise
5
-17 If a Tire Goes Flat
5
-18 Changing a Flat Tire
5
-30 Compact Spare Tire (If Equipped)
5
-31 If You're Stuck: In Sand, Mud, Ice or Snow
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5-2
Hazard Warning Flashers
Your hazard warning flashers let you warn others. They
also let police know you have a problem. Your front and
rear turn signal lamps will flash on and off.
Press the button located
on top of the steering
column all the way down
to make your front and
rear turn signal lamps
flash on and off.
Your hazard warning flashers work no matter what
position your key is in, and even if the key isn't in.
To turn off the flashers, press the button until the first
click and release.
When the hazard warning flashers are on, your turn
signals won't work.
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5-3
Other Warning Devices
If you carry reflective triangles, you can set one up at
the side of the road about 300 feet (100 m) behind
your vehicle.
Jump Starting
If your battery has run down, you want to use another
vehicle and some jumper cables to start your vehicle.
But please use the following steps to do it safely.
CAUTION:
Batteries can hurt you. They can be
dangerous because:

They contain acid that can burn you.

They contain gas that can explode or ignite.

They contain enough electricity to burn you.
If you don't follow these steps exactly, some or
all of these things can hurt you.
NOTICE:
Ignoring these steps could result in costly damage
to your vehicle that wouldn't be covered by
your warranty.
The ACDelco battery in your vehicle has a
built
-in hydrometer. Do not charge, test or
jump start the battery if the hydrometer looks
clear or light yellow. Replace the battery when
there is a clear or light yellow hydrometer and
a cranking complaint.
Trying to start your vehicle by pushing or pulling
it won't work, and it could damage your vehicle.
1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
NOTICE:
If the other system isn't a 12-volt system with a
negative ground, both vehicles can be damaged.
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5-4
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able
to start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling,
set the parking brake firmly on both vehicles
involved in the procedure. Put an automatic
transmission in PARK (P) and put a manual
transmission in NEUTRAL. Be sure the transfer
case is not in NEUTRAL.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter, or accessory power outlets (if equipped).
Turn off all lamps that aren't needed as well as
radios. This will avoid sparks and help to save both
batteries. In addition, it could save your radio!
NOTICE:
If you leave your radio on, it could be badly
damaged. The repair wouldn't be covered by
your warranty.
4. Open both hoods and locate the batteries.
(Your vehicle's battery is located towards the front
of the vehicle, on the passenger side of the engine
compartment. See ªEngine Compartment Overviewº in
the Index for more information on location.) Find the
positive (+) and negative (
-) terminals on each battery.
CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use a flashlight if
you need more light.
Be sure the battery has enough water. You don't
need to add water to the ACDelco
battery
(or batteries) installed in every new GM vehicle.
But if a battery has filler caps, be sure the right
amount of fluid is there. If it is low, add water to
take care of that first. If you don't, explosive gas
could be present.
Battery fluid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
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5-5
CAUTION:
Fans or other moving engine parts can injure you
badly. Keep your hands away from moving parts
once the engine is running.
5. Check that the jumper cables don't have loose or
missing insulation. If they do, you could get a shock.
The vehicles could be damaged too.
Before you connect the cables, here are some
basic things you should know. Positive (+) will go
to positive (+) and negative (
-) will go to a heavy,
unpainted metal engine part. Don't connect
positive (+) to negative (
-) or you'll get a short that
would damage the battery and maybe other parts too.
And don't connect the negative (
-) to negative (-).
6. Connect the red
positive (+) cable to
the positive (+) terminal
of the vehicle with the
dead battery.
7. Don't let the other
end touch metal.
Connect it to the
positive (+) terminal
of the good battery.
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5-6
8. Now connect the black
negative (
-) cable to
the good battery's
negative (
-) terminal.
Don't let the other end touch anything until the next
step. The other end of the negative (
-) cable doesn't
go to the dead battery. It goes to a heavy, unpainted
metal part on the engine of the vehicle with the
dead battery.
9. Attach the cable at least
18 inches (45 cm) away
from the dead battery,
but not near engine parts
that move. The electrical
connection is just as
good there, but the
chance of sparks getting
back to the battery is
much less.
10. Now start the vehicle with the good battery and run
the engine for a while.
11. Try to start the vehicle with the dead battery. If it won't
start after a few tries, make sure all connections are
good. If it still won't start, it probably needs service.
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