transmission GMC ENVOY 2004 Owner's Guide

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

Service............................................................5-3
Doing Your Own Service Work.........................5-3
Adding Equipment to the
Outside of Your Vehicle...............................5-4
Fuel................................................................5-4
Gasoline Octane............................................5-4
Gasoline Specications....................................5-5
California Fuel...............................................5-5
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-6
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-16
Engine Air Cleaner/Filter................................5-21
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-25
Radiator Pressure Cap..................................5-27
Engine Overheating.......................................5-28
Cooling System............................................5-29
Engine Fan Noise.........................................5-36Power Steering Fluid.....................................5-37
Windshield Washer Fluid................................5-38
Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-43
Rear Axle.......................................................5-49
Four-Wheel Drive............................................5-50
Front Axle......................................................5-51
Bulb Replacement..........................................5-52
Halogen Bulbs..............................................5-52
Headlamps..................................................5-52
Front Turn Signal and Sidemarker Lamps........5-52
Taillamps and Turn Signal Lamps...................5-52
Replacement Bulbs.......................................5-54
Windshield Wiper Blade Replacement..............5-54
Tires..............................................................5-57
Ination - Tire Pressure.................................5-65
Tire Inspection and Rotation...........................5-66
When It Is Time for New Tires.......................5-68
Buying New Tires.........................................5-68
Uniform Tire Quality Grading..........................5-69
Section 5 Service and Appearance Care
5-1

A. Coolant Recovery Tank. SeeEngine Coolant on
page 5-25.
B. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-21.
C. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-38.
D. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.
E. Automatic Transmission Dipstick. SeeAutomatic
Transmission Fluid on page 5-22.
F. Engine Oil Dipstick. SeeEngine Oil on page 5-16.G. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-27.
H. Engine Oil Fill Cap. SeeEngine Oil on page 5-16.
I. Remote Negative (-) Terminal Marked GND.
SeeJump Starting on page 5-43.
J. Brake Master Cylinder. SeeBrakes on page 5-39.
K. Battery. SeeBattery on page 5-42.
L. Engine Compartment Fuse Block. See “Engine
Compartment Fuse Block” underFuses and Circuit
Breakers on page 5-101.
5-13

A. Coolant Recovery Tank. SeeEngine Coolant on
page 5-25.
B. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-21.
C. Windshield Washer Fluid Reservoir. SeeWindshield
Washer Fluid on page 5-38.
D. Engine Oil Dipstick. SeeEngine Oil on page 5-16.
E. Automatic Transmission Dipstick. SeeAutomatic
Transmission Fluid on page 5-22.
F. Engine Oil Fill Cap. SeeEngine Oil on page 5-16.
G. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-27.H. Remote Negative (-) Terminal Marked GND. See
Jump Starting on page 5-43.
I. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-37.
J. Brake Master Cylinder. SeeBrakes on page 5-39.
K. Engine Compartment Fuse Block. See “Engine
Compartment Fuse block” underFuses and Circuit
Breakers on page 5-101.
L. Battery. SeeBattery on page 5-42.
5-15

How to Inspect
To inspect the air cleaner/lter, remove the lter from
the vehicle and lightly shake lter to release loose dust
and dirt. If the lter remains “caked” with dirt, a new
lter is required.
To inspect or replace the lter, do the following:
1. Remove the screws on the engine 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. Install the new 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.
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).
5-22

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.
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’s colder than 50°F (10°C), you
may have to idle the engine longer. Should the uid
level be low during this cold check, youmustcheck the
uid hot before adding uid. Checking the uid hot
will give you a more accurate reading of the uid level.
5-23

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.
Then, without shutting off the engine, follow these steps:
The automatic
transmission dipstick
handle with the
transmission and lock
symbol is located in the
engine compartment
on the passenger’s side of
the vehicle.SeeEngine Compartment Overview on page 5-12for
more information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again. Check both sides of the
dipstick, and read the lower level.
3. If the uid level is in the acceptable range, push the
dipstick back in all the way; then ip the handle
down to lock the dipstick in place.
5-24

How to Add 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 doesn’t take much uid, generally less than one
pint (0.5 L).Don’t overll.
Notice:We recommend you use only uid labeled
DEXRON
®-III, because uid with that label is
made especially for your automatic transmission.
Damage caused by uid other than DEXRON
®-III is
not covered by your new vehicle warranty.
After adding uid, recheck the uid level as
described under “How to Check″.
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 5 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 5-28.
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.
5-25

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