2003 GMC YUKON DENALI automatic transmission fluid

Parking on Hills
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
2. Have someone place chocks under the trailer
3. When the wheel chocks are in place, release the
PARK
(P) yet.
wheels.
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
5. Release the regular brakes.
parking brake
and shift into PARK
(P).
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, belts, 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.
4-55

Section 5 Service and Appearance Care
Service ............................................................ 5.3
Doing Your Own Service Work
......................... 5-3
Adding Equipment
to the Outside of Your
Vehicle
.................................................. 5-4
................................................................ Fuel 5.5
Gasoline Octane ............................................ 5.5
Gasoline Specifications ................................... 5-5
California Fuel ............................................... 5-6
Additives
....................................................... 5.6
Fuels in Foreign Countries
............................... 5-6
Filling Your Tank
............................................ 5-7
Filling a Portable Fuel Container ....................... 5.9
the Hood .................... , .................... 5.10
Hood Release ...................... ................ 5-10
Engine Compartment Overview ....... ......... 5-12
Engine Oil ....................................... ..... 5.13
Engine Air Cleaner/Filter ............................. 5.17
Automatic Transmission Fluid ......................... 5-20
Engine Coolant ......................................... 5-22
Checking Things Under
~~
Coolant Surge Tank Pressure Cap ............... 5-25
Engine Overheating ....................................... 5-25
Cooling System ............................................ 5.28
Engine Fan Noise ......................................... 5.33
Power Steering Fluid
..................................... 5-34
Windshield Washer Fluid
................................ 5.34
Brakes
........................................................ 5.36
Battery
........................................................ 5-39
Jump Starting
............................................... 5.40
All-Wheel Drive .............................................. 5.46
Rear Axle .................................. .......... 5-48
Bulb Replacement .......................................... 5-49
Halogen Bulbs .............................................. 5-49
Headlamps
.................................................. 5-49
Running Lamps
......................................... 5-50
Center High-Mounted Stoplamp (CHMSL) ......... 5-52
Taillamps ..................................................... 5-52
Replacement Bulbs ................................... 5.53
Front Turn Signal, Sidemarker and Daytime
5- 1

A. Engine Air CleanedFilter
B. Coolant Surge Tank
C. Air Filter Restriction Indicator
D. Engine Qii Dipstick
E. Engine Oil Fill
F. Automatic Transmission Dipstick
G. Fan
H. Remote Negative (-) Terminal (GND)
I. Remote Positive (+) Terminal
J. Power Steering Fluid Reservoir (Out of View)
K. Brake Master Cylinder Reservoir
L. Underhood Fuse Block
M. Battery
N. Windshield Washer Fluid Reservoir
Before closing the hood, be sure all filler caps are on
properly. Pull down the hood and close
it firmly.
Engine Oil
If the CHECK OIL LEVEL message appears on the
instrument cluster, it means you need to check
your engine oil level right away.
For more information, see “CHECK OIL LEVEL” under
DIC Warnings and Messages on page 3-52.
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It’s 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 has a yellow loop handle and
is located in the engine
compartment on the
passenger’s side of the
vehicle. See Engine
Compartment Overview on
page
5- 12 for more
information on location.
Turn
off the engine and give the oil several minutes to
drain back into the oil pan. If you don’t, the oil
dipstick might not show the actual level.
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.
5-1 3

Automatic Transmission Fluid
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change both the fluid and filter every
50,000 miles
(83
000 km) if the vehicle’s GVWR is over 8,600 or 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.
0 In hilly or mountainous terrain.
When doing frequent trailer towing.
Uses such as found in taxi, police or delivery
service.
If your vehicle’s GVWR is not over 8,600 and you do
not use your vehicle under any of these conditions,
change the fluid and filter every
100,000 miles
(1 66 000 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 fluid can damage
your transmission. Too much can mean that some of the fluid could come out and fall
on hot engine
part or exhaust system parts, starting a fire.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission fluid.
Wait at least 30 minutes before checking the
transmission fluid 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.
See
Part A: Scheduled Maintenance Services on
page 6-4.
5-20

See Engine Compartment Overview on page 5-12 for
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.
3. Check both sides of the dipstick, and read the lower
level. The fluid level must be in the COLD area,
below the cross-hatched area, for a cold check or in
the HOT area or cross-hatched area for a
hot check.
4. If the fluid level is in the acceptable range, push the
dipstick back in all the way; then flip the handle
down
to lock the dipstick in place.
How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid
to use. See Part D:
Recommended Fluids and Lubricants on page 6-15.
Add fluid only after checking the transmission fluid while
it is hot. (A cold check is used only as
a reference.) If
the fluid level is low, add only enough of the proper fluid
to bring the level up to the HOT area for a hot check.
It doesn't take much fluid, generally less than one
pint (0.5 L). Don't overfill.
Notice: We recommend you use only fluid labeled
DEXRON@
-111, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than DEXRON@
-111 is
not covered by your new vehicle warranty.
After adding fluid, recheck the fluid level as
described under How to Check.
When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down
to lock the dipstick in place.
Engine Coolant
The cooling system in your vehicle is filled 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 first, if you add
only DEX-COOL@ extended life coolant.
5-22

37,500 Miles (62 500 km)
U Check readfront axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.
page 5-56 for proper rotation pattern and additional
information. (See footnote
+.)
U Rotate tires. See Tire inspection and Rotation on
45,000 Miles (75 000 km)
D Check readfront axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.
page 5-56 for proper rotation pattern and additional
information. (See footnote
+.)
U Rotate tires. See Tire Inspection and Rotation on
50,000 Miles (83 000 km)
0 Change automatic transmission fluid and filter 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 fluid and filter at
100,000 miles
(166
000 km).
52,500 Milles (87 500 km)
U Check readfront axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.
page 5-56 for proper rotation pattern and additional
information. (See footnote
+.)
D Rotate tires. See Tire lnspection and Rotation on
60,000 Miles (100 000 km)
U Check readfront axle fluid level and add fluid as
needed. Check constant velocity joints and axle seals
for leaking.
page 5-56 for proper rotation pattern and additional
information. (See footnote
+.)
Ll Replace fuel filter. An Emission Control Service.
(See footnote
t.)
lJ Inspect Evaporative Control System. Check all fuel
and vapor lines and hoses for proper hook-up,
routing and condition. Check that the purge valve
works properly,
if equipped. Replace as needed.
An Emission Control Service. (See footnote
t.)
U Rotate tires. See Tire lnspection and Rotation on
6-i

100,000 Miles (166 000 km)
0 Inspect spark plug wires. An Emission Control
ii Repiace spark piugs. An Emission Zoniroi Service.
0 Change automatic transmission fluid and filter if
the vehicle is mainly driven under one or more
of these conditions:
Service.
- 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.
Ll If you haven’t used your vehicle under severe service
conditions listed previously and, therefore, haven’t
changed your automatic transmission fluid, change
both the fluid and filter.
150,000 Miles (240 000 km)
0 Drain, flush and refill cooling system (or every
60 months since last service, whichever occurs first). See
Engine Codant on page 5-22 for what to me.
Inspect hoses. Clean radiator, condenser, pressure
cap and neck. Pressure test the cooling system
and pressure cap. An Emission Control Service.
0 Inspect engine accessory drive belt. An Emission
Control Service.
U Inspect Positive Crankcase Ventilation (PCV) valve.
An Emission Control Service.
6-9

Also look for any opened or broken air bag coverings,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
Inspect wiper blades for wear or cracking. Replace
blade inserts that appear worn or damaged or that
streak or miss areas of the windshield.
Also see
Cleaning the Outside
of Your Vehicle on page 5-81.
Spare Tire Check
At least twice a year, after the monthly inflation check of
the spare tire determines that the spare is inflated
to
the correct tire inflation pressure, make sure that
the spare tire is stored securely. Push, pull, and then
try
to rotate or turn the tire. If it moves, use the wheel
wrenchhatchet
to tighten the cable. See Changing a Flat
Tire
on page 5-63.
Engine Air Cleaner Filter Restriction
Indicator Check
Your vehicle has an engine air cleaner filter restriction
indicator located on the air cleaner in the engine
compartment. The indicator lets you know when the air
cleaner filter is dirty and needs
to be changed. Check
the indicator at least twice a year or when your engine oil is changed,
whichever occurs first. See Engine Air
Cleaner/Filter
on page 5- 17 for more information. Inspect
your air cleaner filter restriction indicator more often
if
the vehicle is used in dusty areas or under off road
conditions.
Weatherstrip Lubrication
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather more frequent application may be required. See
Part D: Recommended Fluids and
Lubricants
on page 6- 15.
Automatic Transmission Check
Check the transmission fluid level; add if needed. See
Automatic Transmission Fluid on page
5-20. A fluid loss
may indicate a problem. Check the system and repair
if needed.
At Least Once a Year
Key Lock Cylinders Service
Lubricate the key lock cylinders with the lubricant
specified in Part D.