2005 GMC ENVOY XL transmission oil

Displacement on Demand (DoD)
Your vehicle’s engine may be equipped with
Displacement on Demand (DoD). This system allows
the engine to operate on either four or eight cylinders,
depending on your driving demands.
The system determines when to switch into and out
of the four-cylinder mode by rst making sure that
certain enabling criteria are met, such as coolant and
oil temperatures, and the transmission being in
either THIRD (3) or FOURTH (4) gear.
When greater power demands are required, such as
accelerating from a stop, passing, or merging onto
a freeway, the system will maintain eight-cylinder
operation. When less power is required, such a
cruising at a constant vehicle speed, the system will
automatically enable the four-cylinder mode, allowing
your vehicle to achieve better fuel economy.
Automatic Transmission Operation
There are several different positions for your gear
shift lever.
PARK (P):This position locks the rear wheels. It is
the best position to use when you start the engine
because your vehicle cannot move easily.
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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 5-26.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet. When parking uphill, turn your wheels
away from the curb. When parking downhill, turn
your wheels into the curb.
2. Have someone place chocks under the
trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
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4. Reapply the regular brakes. Then apply your
parking brake, and then shift into PARK (P).
5. Release the regular brakes.
{CAUTION:
It can be dangerous to get out of your vehicle if
the shift lever is not fully in PARK (P) with the
parking brake rmly set. Your vehicle can roll.
If you have left the engine running, the vehicle
can move suddenly. You or others could be
injured. To be sure your vehicle will not move,
even when you are on fairly level ground, use
the steps that follow.
Always put the shift lever fully in PARK (P) with
the parking brake rmly set.
If the transfer case on four-wheel drive vehicles
is in NEUTRAL, your vehicle will be free to roll,
even if your shift lever is in PARK (P). So, be
sure the transfer case is in a drive gear — not in
NEUTRAL.
SeeFour-Wheel Drive on page 2-27.
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.
4-64

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside
of Your Vehicle...........................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-10
Hood Release..............................................5-11
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-19
Automatic Transmission Fluid.........................5-21
Engine Coolant.............................................5-23
Radiator Pressure Cap..................................5-26
Engine Overheating.......................................5-26
Cooling System............................................5-28
Engine Fan Noise.........................................5-33
Power Steering Fluid.....................................5-34Windshield Washer Fluid................................5-34
Brakes........................................................5-35
Battery........................................................5-38
Jump Starting...............................................5-39
Rear Axle.......................................................5-43
Four-Wheel Drive............................................5-44
Front Axle......................................................5-44
Bulb Replacement..........................................5-45
Halogen Bulbs..............................................5-45
Headlamps, Front Turn Signal, Sidemarker,
and Parking Lamps....................................5-46
Taillamps, Turn Signal, and Stoplamps............5-46
Back-Up Lamps............................................5-47
Replacement Bulbs.......................................5-47
Windshield Wiper Blade Replacement..............5-48
Tires..............................................................5-50
Tire Sidewall Labelling...................................5-51
Tire Terminology and Denitions.....................5-54
Ination - Tire Pressure.................................5-56
Tire Inspection and Rotation...........................5-57
When It Is Time for New Tires.......................5-59
Buying New Tires.........................................5-59
Uniform Tire Quality Grading..........................5-60
Wheel Alignment and Tire Balance..................5-61
Section 5 Service and Appearance Care
5-1

A. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-19.
B. Engine Coolant Recovery Tank. SeeCooling System
on page 5-28.
C. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-34.
D. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-34.
E. Automatic Transmission Fluid Dipstick (Out of View).
See “Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-21.
F. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-15.G. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-26.
H. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
I. Remote Negative (−) Terminal (Marked GND).
SeeJump Starting on page 5-39.
J. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-35.
K. Battery. SeeBattery on page 5-38.
L. Engine Compartment Fuse Block. SeeEngine
Compartment Fuse Block on page 5-92.
5-13

A. Engine Coolant Recovery Tank. SeeCooling System
on page 5-28.
B. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-19.
C. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-34.
D. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-15.
E. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-21.
F. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
G. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-26.
H. Remote Negative (−) Terminal (Marked GND).
SeeJump Starting on page 5-39.
I. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-34.
J. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-35.
K. Engine Compartment Fuse Block. SeeEngine
Compartment Fuse Block on page 5-92.
L. Battery. SeeBattery on page 5-38.Engine Oil
Checking Engine Oil
It is a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview on page 5-12for
the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-15

Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
A good time to check your automatic transmission uid
level is when the engine oil is changed.
Change the uid and lter at the intervals listed in
Additional Required Services on page 6-6, and be sure
to use the transmission uid listed inRecommended
Fluids and Lubricants on page 6-12.
How to Check Automatic Transmission
Fluid
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 is 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.
A cold uid 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 ve minutes if outside
temperatures are 50°F (10°C) or more. If it is colder
than 50°F (10°C), you may have to idle the engine
longer. Should the uid level be low during this cold
check, you must check the uid hot before adding uid.
Checking the uid hot will give you a more accurate
reading of the uid level.
5-21

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