2003 GMC SIERRA DENALI transmission

When You Are Ready to Leave After
Parking on a
Hill
1. Apply your regular brakes and hold the pedal down
while you:
0 start your engine,
shift into a gear, and
0 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, belt, 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.
4-59

Section 5 Service and Appearance Care
Service ............................................................ 5.3
Doing Your Own Service Work
......................... 5-4
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
................. ....... 5.7
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
Checking
Things Under
Engine Oil
................................................... 5.13
Engine Air Cleaner/Filter
................................ 5.19
Engine Coolant
............................................. 5.24
Engine Overheating
....................................... 5.27
Cooling System
............................................ 5.30
Automatic
Transmission Fluid
........................ -5-21
Coolant Surge Tank Pressure Cap
.................. 5-27 Engine
Fan Noise
......................................... 5.36
Power Steering Fluid
..................................... 5.37
Windshield Washer Fluid
................................ 5-38
Brakes
........................................................ 5.39
Battery
........................................................ 5.42
Jump Starting
............................................... 5.43
All-Wheel Drive
......................... .............. 5-49
Rear Axle
....................................................... 5-50
Front Axle
...................................................... 5-51
Bulb Replacement
.......................................... 5-52
Halogen Bulbs
.............................................. 5-52
Headlamps
................................................. -5-52
Roof Marker Lamps
...................................... 5-54
Cargo Lamp
............................................. 5-56
Taillamps
..................................................... 5-58
Replacement Bulbs
....................................... 5-59
Front
Turn Signal, Sidemarker
and Daytime
Running Lamps
......................................... 5-53
Center High-Mounted Stoplamp (CHMSL) and
Pickup
Box Identification and Fender Marker
Lamps
..................................................... 5-58
Windshield Wiper Blade Replacement
.............. 5-60
5-
1

A. Engine Air CleanedFilter
B. Coolant Surge Tank
C. Air CleanerlFilter Restriction Indicator
B. Engine Oil Dipstick
E. Engine Oil Fill Cap
F. Automatic Transmission Dipstick
G. Fan
H. Remote Negative
(-) Terminal (GND)
I. Remote Positive (+) Terminal
J. Power Steering Fluid Reservoir
K. Brake Fluid Reservoir
L. Underhood Fuse Block
M. Battery
N. Windshield Washer Fluid Reservoir
Engine Oil
If the CHECK ENG 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 ENG
OIL LEVEL”
under
DIC Warnings and Messages on page 3-53.
You should check your engine oil level regularly; this is
an added reminder.
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 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
If you do not use your vehicle under any of these
conditions, change the fluid and filter every
100,000 miles (1 66 000 km).
See
Part A: Scheduled Maintenance Services on
page
6-4.
service.
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:
0 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 fluid should be at normal
operating temperature, which is 180°F
to 200°F
(82°C to 93°C).
5-2
1

Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above
50°F
(1 OOC). If it's colder than 50°F (lO°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 (1 0°C) or
more.
If it's colder than 50°F (1 OOC), 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:
The red transmission dipstick handle is located at the
rear of the engine compartment, on the passenger's
side. See
Engine Compartment Overview on page 5-12
for further information on location.
1. Flip the handle up and then pull out the dipstick
and wipe it with a clean rag or paper towel.
3. Push it back in all the way, wait three seconds and
then pull it back out again.
5-22

~~ 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
6-16.
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 overfi//.
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.
5-23

6. Then replace the
pressure cap. Be sure
the pressure cap is
hand-tight and
fully seated. Engine Fan Noise
Your 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 fan is spinning slower and the clutch is not fully
engaged. This improves fuel economy and reduces fan
noise. Under heavy vehicle loading, trailer towing and/or
high outside temperatures, the fan speed increases as
the clutch more fully 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 partially
disengages.
5-36

Notice: If the other system isn’t a 12-volt system
with a negative ground, both vehicles can be
damaged.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren’t touching
each other. If they are, it could cause a ground
connection you don’t want. You wouldn’t 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 firmly on both vehicles involved
in the jump start procedure. Put the automatic
transmission in PARK
(P) before setting the parking
brake.
If you have a four-wheel-drive vehicle, be
sure the transfer case is in a drive gear not in
NEUTRAL.
Notice: If you leave your radio on, it could be badly
damaged. The repairs wouldn’t be covered by
your warranty.
3.
4.
Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the accessory power outlets. Turn
off
the radio and all the lamps that aren’t needed.
This will avoid sparks and help save both batteries.
And it could save your radio!
Open the hoods and locate the positive
(+) and
negative
(-) terminal locations of the other vehicle.
Your vehicle has a remote positive
(+) jump starting
terminal and a remote negative
(-) jump starting
terminal. You should always use these remote
terminals instead of the terminals on the battery.
The remote positive
(+) terminal is located behind
a red plastic cover near the engine accessory
drive bracket.
To uncover the remote positive (+)
terminal, open the red plastic cover.
The remote negative
(-) terminal is located on the
engine drive bracket on all
V8 and diesel
engines, and on the thermostat housing on the
8.1L engine. On
V8 engines it is marked ”GND.”
See
Engine Compartment Overview on page 5-12
for more information on location.
5-44