2005 GMC ENVOY XL light

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
Dark Blue: Electric Brakes
Red: Battery Feed (The chassis wiring ring
terminal must be fastened to a stud on the
underhood electrical center before the trailer feed
will become active.)
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.
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{CAUTION:
If you spill fuel and then something ignites it,
you could be badly burned. Fuel can spray out
on you if you open the fuel cap too quickly.
This spray can happen if your tank is nearly
full, and is more likely in hot weather. Open
the fuel cap slowly and wait for any hiss noise
to stop. Then unscrew the cap all the way.
Be careful not to spill fuel. Do not top off or overll the
tank and wait a few seconds after you have nished
pumping before removing the nozzle. Clean fuel
from painted surfaces as soon as possible. See
Washing Your Vehicle on page 5-85.
When replacing the fuel cap, turn it clockwise until it
clicks. Make sure the cap is fully installed. The
diagnostic system can determine if the fuel cap has
been left off or improperly installed. This would allow fuel
to evaporate into the atmosphere. SeeMalfunction
Indicator Lamp on page 3-41.There may also be a light that comes on in the
instrument panel to let you know if your gas cap is
not properly installed. SeeCheck Gas Cap Light
on page 3-48for more information.
{CAUTION:
If a re starts while you are refueling, do not
remove the nozzle. Shut off the ow of fuel
by shutting off the pump or by notifying the
station attendant. Leave the area immediately.
Notice:If you need a new fuel cap, be sure to get
the right type. Your dealer can get one for you.
If you get the wrong type, it may not t properly.
This may cause your malfunction indicator lamp to
light and may damage your fuel tank and emissions
system. SeeMalfunction Indicator Lamp on
page 3-41.
5-9

If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use 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
Do not add anything to your oil. The recommended
oils with the starburst symbol that meet GM Standard
GM6094M are all you will need for good performance
and engine protection.
Engine Oil Life System
When to Change Engine Oil
Your vehicle has a computer system that lets you
know when to change the engine oil and lter. This is
based on engine revolutions and engine temperature,
and not on mileage. Based on driving conditions,
the mileage at which an oil change will be indicated
can vary considerably. For the oil life system to
work properly, you must reset the system every time
the oil is changed.When the system has calculated that oil life has
been diminished, it will indicate that an oil change is
necessary. A change engine oil light will come on.
SeeChange Engine Oil Light on page 3-45. Change
your oil as soon as possible within the next 600 miles
(1 000 km). It is possible that, if you are driving
under the best conditions, the oil life system may not
indicate that an oil change is necessary for over a year.
However, your engine oil and lter must be changed
at least once a year and at this time the system must be
reset. Your dealer has GM-trained people who will
perform this work using genuine GM parts and reset the
system. It is also important to check your oil regularly
and keep it at the proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since your
last oil change. Remember to reset the oil life system
whenever the oil is changed.
How to Reset the Engine Oil Life
System
The Engine Oil Life System calculates when to change
your engine oil and lter based on vehicle use. Anytime
your oil is changed, reset the system so it can calculate
when the next oil change is required. If a situation occurs
where you change your oil prior to a change engine oil
light being turned on, reset the system.
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To reset the change engine oil light, do the following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal slowly
three times within ve seconds.
3. Turn the key to LOCK.
If the change engine oil light comes back on when you
start your vehicle, the engine oil life system has not
reset. Repeat the procedure.
For vehicles with the Driver Information Center, see
Driver Information Center (DIC) on page 3-49to reset
the system.
What to Do with Used Oil
Used engine oil contains certain elements that may be
unhealthy for your skin and could even cause cancer.
Do not let used oil stay on your skin for very long. Clean
your skin and nails with soap and water, or a good
hand cleaner. Wash or properly dispose of clothing or
rags containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil products.Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil from the
lter before disposal. Never dispose of oil by putting it
in the trash, pouring it on the ground, into sewers, or into
streams or bodies of water. Instead, recycle it by
taking it to a place that collects used oil. If you have a
problem properly disposing of your used oil, ask
your dealer, a service station or a local recycling
center for help.
Engine Air Cleaner/Filter
SeeEngine Compartment
Overview on page 5-12
for the location of the
engine air cleaner/lter.
5-19

When to Inspect the Engine
Air Cleaner/Filter
Inspect the air cleaner/lter at the MaintenanceII
intervals and replace at the rst oil change after each
50,000 mile (83 000 km) interval. SeeScheduled
Maintenance on page 6-4for more information. If you
are driving in dusty/dirty conditions, inspect the lter
at each engine oil change.
How to Inspect the Engine
Air Cleaner/Filter
To inspect the air cleaner/lter remove the lter from the
vehicle and lightly shake the lter to release loose
dust and dirt. If the lter remains caked with dirt, a new
lter is required.
To inspect or replace the engine air cleaner/lter, do the
following:
1. Remove the screws on the engine air cleaner/lter
and lift off the cover.
2. Remove the air cleaner/lter from the housing. Care
should be taken to dislodge as little dirt as possible.3. Inspect or replace the engine air cleaner/lter.
4. Reinstall the cover and tighten the screws.
{CAUTION:
Operating the engine with the air cleaner/lter
off can cause you or others to be burned.
The air cleaner not only cleans the air; it helps
to stop ame if the engine backres. If it is
not there and the engine backres, you could
be burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/lter off.
Notice:If the air cleaner/lter is off, a backre
can cause a damaging engine re. And, dirt
can easily get into your engine, which will damage
it. Always have the air cleaner/lter in place
when you are driving.
5-20

How to Add Automatic
Transmission Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission uid to use. SeeRecommended
Fluids and Lubricants on page 6-12.
Add uid only after checking the transmission uid while
it is hot. A cold check is used only as a reference. If
the uid level is low, add only enough of the proper uid
to bring the level up to the HOT area for a hot check.
It does not take much uid, generally less than one pint
(0.5 L). Do not overll.
Notice:Use of the incorrect automatic transmission
uid may damage your vehicle, and the damages
may not be covered by your warranty. Always
use the automatic transmission uid listed in
Recommended Fluids and Lubricants on page 6-12.
After adding uid, recheck the uid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
When the correct uid level is obtained, push the
dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for ve years or 150,000 miles
(240 000 km), whichever occurs rst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-26.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core or radiator
corrosion. In addition, the engine coolant may
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your vehicle.
5-23

Always clean the brake uid reservoir cap and the
area around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of uid in your brake
system, your brakes may not work well, or
they may not even work at all. This could
cause a crash. Always use the proper
brake uid.
Notice:
Using the wrong uid can badly damage
brake system parts. For example, just a
few drops of mineral-based oil, such as engine
oil, in your brake system can damage brake
system parts so badly that they will have to
be replaced. Do not let someone put in the
wrong kind of uid.
If you spill brake uid on your vehicle’s painted
surfaces, the paint nish can be damaged. Be
careful not to spill brake uid on your vehicle. If
you do, wash it off immediately. SeeAppearance
Care on page 5-81.
Brake Wear
Your vehicle has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched warning sound when the brake pads
are worn and new pads are needed. The sound
may come and go or be heard all the time your vehicle
is moving, except when you are pushing on the
brake pedal rmly.
{CAUTION:
The brake wear warning sound means that
soon your brakes will not work well. That
could lead to an accident. When you hear the
brake wear warning sound, have your vehicle
serviced.
Notice:Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are rst applied or lightly
applied. This does not mean something is wrong with
your brakes.
5-37

2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles are not touching
each other. If they are, it could cause a ground
connection you do not want. You would not 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 rmly on both vehicles involved in
the jump start procedure. Put an automatic
transmission in PARK (P) or a manual transmission
in NEUTRAL before setting the parking brake. If
you have a four-wheel-drive vehicle, be sure
the transfer case is not in NEUTRAL.
Notice:If you leave your radio or other accessories
on during the jump starting procedure, they could
be damaged. The repairs would not be covered
by your warranty. Always turn off your radio and
other accessories when jump starting your vehicle.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or the accessory power outlets, if equipped.
Turn off the radio and all lamps that are not
needed. This will avoid sparks and help to save
both batteries. And it could save the radio!
4. Open both hoods and locate the batteries. Find the
positive (+) and negative (−) terminals on each
battery. Your vehicle has a remote negative (−) jump
starting terminal. You should always use thisremote terminal instead of the terminal on the
battery. The remote negative (−) terminal is located
on the front engine lift bracket on vehicles with
the 4.2L L6 engine or the engine accessory drive
bracket for vehicles with the 5.3L V8 engine, and is
marked GND (Ground). SeeEngine Compartment
Overview on page 5-12for more information on
location.
{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
ashlight if you need more light.
Be sure the battery has enough water. You do
not need to add water to the battery installed
in your new vehicle. But if a battery has ller
caps, be sure the right amount of uid is there.
If it is low, add water to take care of that rst.
If you do not, explosive gas could be present.
Battery uid contains acid that can burn you.
Do not get it on you. If you accidentally get it
in your eyes or on your skin, ush the place
with water and get medical help immediately.
5-40