2003 GMC YUKON DENALI brake fluid

Transmission Temperature Gage
--
United States Canada
Your vehicle is equipped with a transmission
temperature gage.
When your ignition is on, the gage shows the
temperature of the transmission fluid. The normal
operating range is from
100°F (38°C) to about 265°F
(1 30°C).
At approximately 265°F (130°C), the DIC will display a
TRANSMISSION HOT message and the transmission
will enter a transmission protection mode. When
the transmission enters the protection mode, you may
notice a change in the transmission shifting patterns.
The transmission will return to normal shifting patterns
when the transmission fluid temperature falls below
260°F
(1 27°C). See
Driver Information
Center (DIC) on page 3-43 for
further information.
If the transmission fluid reaches temperatures of
approximately 275°F (135°C) or greater, the DIC will
display a TRANS
HOT tDLE ENGtNE warning message
and a chime will sound. Pull the vehicle
off the
roadway when it is safe
to do so. Set the parking brake,
place the transmission in PARK
(P) and allow the
engine to idle until the transmission temperature falls
below 260°F (127°C).
If the transmission continues
to operate above 265°F
(1 30"C), please contact your
nearest dealer or the
GM Roadside Assistance Center.
Notice: If you keep driving your vehicle with the
transmission temperature gage above the normal
operating range, you can damage the transmission.
This could lead to costly repairs that may not be
covered under your warranty.
The following situations can cause the transmission to
operate at higher temperatures:
0 Towing a trailer,
* hot outside air temperatures,
0 hauling a large or heavy load,
low transmission fluid level,
high transmission fluid level,
0 restricted air flow to the radiator.

The heavier the rain, the harder it is to see. Even if your
windshield wiper blades are in good shape, a heavy
rain can make it harder to see road signs and
traffic signals, pavement markings, the edge of the road
and even people walking.
It’s wise to keep your wiping equipment in good shape
and keep your windshield washer tank filled with
washer fluid. Replace your windshield wiper inserts
when they show signs of streaking or missing areas on
the windshield, or when strips of rubber start to
separate from the inserts. Driving too fast through large
water puddles or even
going through some car washes can cause problems,
too. The water may affect your brakes. Try to avoid
puddles. But
if you can’t, try to slow down before
you hit them.
Wet brakes can cause accidents. They won’t
work as well in a quick stop and may cause
pulling to one side. You could lose control
of
the vehicle.
After driving through a large puddle
of water
or a car wash, apply your brake pedal lightly
until your brakes work normally.
4-30

0 Keep your vehicle in good shape. Check all fluid
levels and also the brakes, tires, cooling system
and transmission. These parts can work hard
on mountain roads.
Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift
to a lower gear when you go
down a steep or long hill.
_. you c tt : ft down, your brakes could get
so hot that they wouldn’t work well. You would
then have poor braking or even none going down
a hill. You could crash. Shift down to let
your engine assist your brakes on
a steep
downhill slope.
L,ast,,,, ,ownh,,, NEUTrlmL (N) or with the
ignition
off is dangerous. Your brakes will have
to do all the work
of slowing down. They could
get so hot that they wouldn’t work well. You
would then have poor braking
or even none
going down
a hill. You could crash. Always
have your engine running and your vehicle in
gear when you go downhill.
Know how to go uphill. You may want to shift down
to a lower gear. The lower gears help cool your
engine and transmission, and you can climb the
hill better.
Stay in your own lane when driving on two-lane
roads in hills or mountains. Don’t swing wide or
cut across the center of the road. Drive at speeds
that let you stay in your own lane.
As you go over the top of a hill, be alert. There
could be something in your lane, like a stalled car or
an accident.
4-36

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

Checking Things Under
the
Hood
- .lings It burn can get c hot engine parts
and start a fire. These include liquids like fuel,
oil, coolant, brake fluid, windshield washer and
other fluids, and plastic or rubber.
You or
others could be burned. Be careful not to drop
or spill things that will burn onto
a hot engine.
Hood Release
To open the hood, do the following:
1. Pull the handle located
inside the vehicle
to
the lower left of
the steering wheel.
5-1 0

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

To get the right reading, the fluid 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
(IO'C), drive the vehicle
in THIRD
(3) until the engine temperature gage
moves and then remains steady for
10 minutes.
A cold fluid 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 five minutes
if outside temperatures are
50°F (10°C) or more.
If it's colder than 50°F (IO'C), you
may have to idle the engine longer. Should the fluid
level be low during this cold check,
you must check the
fluid hot before adding fluid. Checking the fluid hot
will give you a more accurate reading of the fluid level.
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:
1- The transmission dipstick handle with the graphic is
located at the rear of
the engine compartment,
on the passenger's side.
5-21