towing GMC ENVOY XL 2004 Owner's Manual

Before you start, check all trailer hitch parts and and
attachments, safety chains, electrical connection, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving your vehicle without a trailer.
This can help you avoid situations that require
heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a good
deal longer, you’ll need to go much farther beyond the
passed vehicle before you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, just move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. Your vehicle could be damaged. Avoid
making very sharp turns while trailering.
When you’re turning with a trailer, make wider turns than
normal. Do this so your trailer won’t strike soft shoulders,
curbs, road signs, trees or other objects. Avoid jerky or
sudden maneuvers. Signal well in advance.
4-62

Turn Signals When Towing a Trailer
The arrows on your instrument panel will ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou
start down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much
that they would get hot and no longer work well.You can tow in DRIVE (D). You may want to shift the
transmission to THIRD (3) or a lower gear, under heavy
loads or hilly conditions.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude on
steep uphill grades, your vehicle may show signs similar
to engine overheating. To avoid this, let the engine run
while parked (preferably on level ground) with the
automatic transmission in PARK (P) for a few minutes
before turning the engine off. If you do get the overheat
warning, seeEngine Overheating on page 5-28.
4-63

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 uid (don’t overll),
engine oil, axle lubricant, belt(s), cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you nd 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.
4-65

Trailer Wiring Harness
Your vehicle may be equipped with the seven-wire trailer
towing harness. This harness has a seven-pin universal
heavy-duty trailer connector that is attached to a bracket
on the hitch platform. The seven-wire harness contains
the following trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Running Lamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed
Dark Blue: Electric Brakes
If you need to tow a light-duty trailer with a standard
four-way round pin connector, an adapter connector is
available from your dealer.
Your vehicle may also be equipped with wiring for an
electric trailer brake controller. These wires are located
inside the vehicle on the driver’s side under the
instrument panel. These wires should be connected to
an electric trailer brake controller by your dealer or
a qualied service center.
4-66

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission uid
level is when the engine oil is changed.
Change both the uid and lter every 50,000 miles
(83 000 km) if the vehicle is mainly driven under one or
more of these conditions:
In heavy city traffic where the outside temperature
regularly reaches 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
100,000 miles (166 000 km).
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 uid can damage
your transmission. Too much can mean that some
of the uid could come out and fall on hot engine
part or exhaust system parts, starting a re.
Too little uid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission uid.
Wait at least 30 minutes before checking the
transmission uid level if you have been driving:
When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
In heavy traffic-especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it’s colder than 50°F (10°C),
drive the vehicle in THIRD (3) until the engine
temperature gage moves and then remains steady
for 10 minutes.
5-22

6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
7. By this time, the coolant level inside the radiator
ller neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through the ller neck until the level reaches
the base of the ller neck.8. Then replace the pressure cap. At any time during
this procedure if coolant begins to ow out of the
ller neck, reinstall the pressure cap. Be sure
the pressure cap is hand-tight.
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 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.
5-36

(h)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.
(i)Drain, ush and rell cooling system. See Engine
Coolant on page 5-24for what to use. Inspect hoses.
Clean radiator, condenser, pressure cap and ller neck.
Pressure test the cooling system and pressure cap.
(j)A uid loss in any vehicle system could indicate a
problem. Have the system inspected and repaired and
the uid level checked. Add uid if needed.Owner Checks and Services
These owner checks and services should be performed
at the intervals specied to help ensure the safety,
dependability and emission control performance of your
vehicle. Your GM Goodwrench dealer can assist you
with these checks and services.
Be sure any necessary repairs are completed at once.
Whenever any uids or lubricants are added to your
vehicle, make sure they are the proper ones, as shown
inRecommended Fluids and Lubricants on page 6-13.
6-9

Compass Calibration.......................................2-36
Compass Operation.........................................2-36
Compass Variance..........................................2-37
Content Theft-Deterrent....................................2-17
Control of a Vehicle.......................................... 4-6
Convenience Net............................................2-51
Coolant
Engine Temperature Gage............................3-42
Heater, Engine............................................2-23
Cooling System..............................................5-30
Cruise Control................................................3-12
Cruise Control Light........................................3-48
CURB VIEW ACTIVATED.................................3-63
Current and Past Model Order Forms................7-13
Customer Assistance Information
Courtesy Transportation.................................. 7-8
Customer Assistance for Text
Telephone (TTY) Users............................... 7-4
Customer Assistance Offices........................... 7-4
Customer Satisfaction Procedure..................... 7-2
GM Mobility Program for Persons with
Disabilities................................................ 7-6
Reporting Safety Defects to General Motors.......7-12
Reporting Safety Defects to the Canadian
Government............................................7-12
Reporting Safety Defects to the United States
Government............................................7-11
Roadside Assistance Program......................... 7-7
Service Publications Ordering Information........7-12D
Daytime Running Lamps (DRL).........................3-17
Defensive Driving............................................. 4-2
Defogging and Defrosting.........................3-23, 3-29
Delayed Locking.............................................2-10
Dinghy Towing................................................4-46
Doing Your Own Service Work........................... 5-3
Dolly Towing..................................................4-48
Dome Lamp Override......................................3-19
Dome Lamps.................................................3-20
Door
Delayed Locking..........................................2-10
Locks.......................................................... 2-8
Power Door Locks......................................... 2-9
Programmable Automatic Door Locks.............2-10
Rear Door Security Locks.............................2-13
Driver
Position, Safety Belt.....................................1-14
DRIVER DOOR AJAR.....................................3-62
Driver Information Center (DIC).........................3-51
DIC Operation and Displays..........................3-51
DIC Warnings and Messages........................3-60
Driving
At Night.....................................................4-30
City...........................................................4-34
Defensive..................................................... 4-2
Drunken....................................................... 4-2
Freeway.....................................................4-35
4

Locks
Delayed Locking..........................................2-10
Door........................................................... 2-8
Leaving Your Vehicle....................................2-13
Lockout Protection.......................................2-13
Power Door.................................................. 2-9
Programmable Automatic Door Locks.............2-10
Rear Door Security Locks.............................2-13
Loss of Control...............................................4-14
Low Fuel Warning Light...................................3-50
Luggage Carrier..............................................2-48
Lumbar
Power Controls............................................. 1-2
M
Maintenance Schedule
Additional Required Services........................... 6-6
At Each Fuel Fill.........................................6-10
At Least Once a Month................................6-10
At Least Once a Year..................................6-11
Introduction.................................................. 6-2
Maintenance Footnotes.................................. 6-8
Maintenance Record....................................6-16
Maintenance Requirements............................. 6-2
Normal Maintenance Replacement Parts.........6-15
Owner Checks and Services........................... 6-9
Recommended Fluids and Lubricants.............6-13
Scheduled Maintenance................................. 6-4Maintenance Schedule (cont.)
Using Your................................................... 6-3
Your Vehicle and the Environment................... 6-2
Maintenance When Trailer Towing.....................4-65
Making Turns.................................................4-62
Malfunction Indicator Light................................3-43
Matching Transmitter(s) to Your Vehicle............... 2-6
Memory Seat.................................................2-53
Message
DIC Warnings and Messages........................3-60
Mexico, Central America and Caribbean
Islands/Countries (Except Puerto Rico
and U.S. Virgin Islands)................................. 7-5
Mirror Operation.............................................2-36
Mirrors
Automatic Dimming Rearview with
OnStar®and Compass..............................2-36
Outside Convex Mirror.................................2-39
Outside Curb View Assist Mirrors...................2-39
Outside Heated Mirrors................................2-39
Outside Manual Mirrors................................2-38
Outside Power Mirrors..................................2-38
MyGMLink.com................................................ 7-4
N
Navigation/Radio System................................3-106
New Vehicle Break-In......................................2-19
Normal Maintenance Replacement Parts............6-15
9

Power Steering...............................................4-11
Programmable Automatic Door Locks.................2-10
Programmable Locking Feature.........................2-11
Programmable Unlocking Feature......................2-12
Programming the HomeLink
®Transmitter...........2-43
Q
Questions and Answers About Safety Belts.........1-13
R
Radiator Pressure Cap....................................5-27
Radio Data System (RDS)...............3-65, 3-76, 3-92
Radio Messages.....................................3-71, 3-83
Radios..........................................................3-64
Care of Your Cassette Tape Player...............3-121
Care of Your CD and DVD Player................3-122
Care of Your CDs and DVDs.......................3-122
Navigation/Radio System.............................3-106
Radio Personalization.................................3-119
Radio with Cassette and CD.........................3-76
Radio with CD............................................3-65
Radio with Six-Disc CD................................3-92
Rear Seat Audio........................................3-117
Setting the Time..........................................3-64
Theft-Deterrent..........................................3-119
Understanding Reception............................3-120Rainsense™ Wipers........................................3-10
RDS Messages..............................3-70, 3-82, 3-97
Reading Lamps..............................................3-20
REAR ACCESS OPEN....................................3-62
Rear Axle......................................................5-48
Locking......................................................4-11
Rear Climate Control System............................3-31
Rear Compartment Storage Panel/Cover............2-49
Rear Door Security Locks................................2-13
Rear Floor Storage Lid....................................2-51
Rear Safety Belt Comfort Guides......................1-24
Rear Seat Audio (RSA)..................................3-117
Rear Seat Entertainment System.....................3-106
Rear Seat Operation......................................... 1-5
Rear Seat Passenger Positions.........................1-21
Rear Seat Passengers, Safety Belts..................1-21
Rear Seats (Envoy XL)..................................... 1-7
Rear Storage Area..........................................2-49
Rear Underseat Fuse Block............................5-104
Rear Window Defogger............................3-24, 3-29
Rearview Mirror, Automatic Dimming
with OnStar
®and Compass..........................2-36
Reclining Seatbacks, Power............................... 1-4
Recommended Fluids and Lubricants.................6-13
Recreational Vehicle Towing.............................4-45
Reduced Engine Power Light............................3-48
Remote Control.............................................3-112
Remote Keyless Entry System............................ 2-5
Remote Keyless Entry System, Operation............ 2-6
11