2004 GMC SIERRA Owner's Manual

{CAUTION:
If you have four-wheel drive, your vehicle will be
free to roll Ð even if your shift lever is in PARK
(P) Ð if your transfer case is in NEUTRAL. So,
be sure the transfer case is in a drive gear,
two-wheel high (2H) or four-wheel high (4H) or
four-wheel low (4L) Ð not in NEUTRAL. See
Shifting Into Park (P) on page 2-49
REVERSE (R):Use this gear to back up. If your vehicle
is equipped with the Allison Transmissionž, the R
may blink on the PRNDL if the shift inhibitor is active.
Notice:Shifting to REVERSE (R) while your vehicle
is moving forward could damage the transmission.
The repairs would not be covered by your warranty.
Shift to REVERSE (R) only after your vehicle is
stopped.
To rock your vehicle back and forth to get out of snow,
ice or sand without damaging your transmission,
see If You Are Stuck: In Sand, Mud, Ice or Snow on
page 4-51.NEUTRAL (N):In this position, your engine doesn't
connect with the wheels. To restart when you're already
moving, use NEUTRAL (N) only. Also, use
NEUTRAL (N) when your vehicle is being towed.
{CAUTION:
Shifting into a drive gear while your engine is
running at high speed is dangerous. Unless
your foot is ®rmly on the brake pedal, your
vehicle could move very rapidly. You could
lose control and hit people or objects. Do not
shift into a drive gear while your engine is
running at high speed.
Notice:Shifting out of PARK (P) or NEUTRAL (N)
with the engine running at high speed may damage
the transmission. The repairs would not be
covered by your warranty. Be sure the engine is not
running at high speed when shifting your vehicle.
2-27

DRIVE (D):This position is for normal driving. If you
need more power for passing, and you're:
·Going less than about 35 mph (55 km/h), push your
accelerator pedal about halfway down.
·Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
You'll shift down to the next gear and have more power.
Drive (D) can be used when towing a trailer, carrying
a heavy load, driving on steep hills or for off-road driving.
You may want to shift the transmission to THIRD (3)
or, if necessary, a lower gear selection if the
transmission shifts too often.
Notice:Extended idling for more than ®ve minutes
in DRIVE (D) on vehicles equipped with the Allison
Transmission may cause transmission overheating
and damage. Always put the gearshift lever in
PARK (P) if idle time is longer than ®ve minutes.
If your vehicle is equipped with the Allison
ž
Transmission, it will initially attain ®rst range when
DRIVE (D) is selected. As vehicle speed increases, the
transmission will upshift automatically through each
available range up to FIFTH (5). As the vehicle slows,
the transmission will downshift automatically.
THIRD (3):This position is also used for normal driving,
however it offers more power and lower fuel economy
than DRIVE (D).SECOND (2):This position gives you more power but
lower fuel economy. You can use SECOND (2) on
hills. It can help control your speed as you go down
steep mountain roads, but then you would also want to
use your brakes off and on.
If you manually select SECOND (2) in a light duty
automatic transmission, the transmission will drive in
second gear. You may use this feature for reducing the
speed of the rear wheels when you are trying to start
your vehicle from a stop on slippery road surfaces.
FIRST (1):This position gives you even more power
(but lower fuel economy) than SECOND (2). You
can use it on very steep hills, or in deep snow or mud.
If the selector lever is put in FIRST (1) while the
vehicle is moving forward, the transmission won't shift
into ®rst gear until the vehicle is going slowly enough.
Notice:Spinning the tires or holding the vehicle in
one place on a hill using only the accelerator
pedal may damage the transmission. If you are
stuck, do not spin the tires. When stopping on a hill,
use the brakes to hold the vehicle in place.
On cold days, approximately 32ÉF (0ÉC) or colder, your
transmission is designed to shift differently until the
engine reaches normal operating temperature. This is
intended to improve heater performance.
2-28

Tow/Haul Mode
(Automatic Transmission)
Your vehicle may be equipped with a Tow/Haul mode.
The selector button is located on the end of the
column shift lever. You can use this feature to assist
when towing or hauling a heavy load. Turn Tow/Haul on
and off by pressing the button until the Tow/Haul
indicator light illuminates on the instrument panel. See
ªTow/Haul Mode²under
Towing a Trailer on page 4-70for more information.
Overdrive Disable
(Allison Transmissionž)
If your vehicle has an Allison Transmissionžyou may
have the overdrive disable feature. The overdrive disable
feature prevents the transmission from shifting into
®fth (5) gear. The selector button is located on the end of
the column shift lever. You can turn overdrive disable on
and off by pressing and holding the button at the end of
the column shift lever until the indicator light, on the
instrument panel, illuminates.
2-29

If your vehicle has both Tow/Haul and overdrive disable
tap the button once to enable or disable Tow/Haul, and
press and hold the button to enable or disable overdrive
disable.
Manual Transmission Operation
Five-Speed
(VORTECŸ 6000 V8 Engine)
Here's how to operate your
transmission.
FIRST (1) is intended only for heavy loads or trailer
towing and is not recommended for normal driving.
During the ®rst 500 miles (805 km) of vehicle use, start
your vehicle moving in FIRST (1). This allows clutch
components to break-in properly.FIRST (1):Press the clutch pedal and shift into
FIRST (1). Then, slowly let up on the clutch pedal as
you press the accelerator pedal. Shift into FIRST (1)
only when the vehicle is below 5 mph (8 km/h). If you try
to shift down into FIRST (1) at excessive vehicle
speeds, the shift lever will not move into FIRST (1) until
vehicle speed is reduced.
SECOND (2):Press the clutch pedal and shift into
SECOND (2). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
You can shift into SECOND (2) when you're going less
than 20 mph (32 km/h). If you've come to a complete
stop and it's hard to shift into SECOND (2), put the shift
lever into NEUTRAL and let up on the clutch. Press
the clutch pedal back down. Then shift into
SECOND (2). If you try to downshift into SECOND (2) at
excessive vehicle speeds, the shift lever will not move
into the SECOND (2) position until the vehicle speed
is reduced.
THIRD (3):Press the clutch pedal and shift into
THIRD (3). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
2-30

FOURTH (4) and FIFTH (5):Shift into the higher
forward gears the same way you do for THIRD (3).
Slowly let up on the clutch pedal as you press the
accelerator pedal.
To stop, let up on the accelerator pedal and press the
brake pedal. Just before the vehicle stops, press
the clutch pedal and the brake pedal, and shift to
NEUTRAL.
NEUTRAL:Use this position when you start or idle
your engine.
REVERSE (R):To back up, ®rst press down the clutch
pedal. Wait for the vehicle to stop moving and then,
shift into REVERSE (R). Let up on the clutch pedal
slowly while pressing the accelerator pedal.
Notice:Shifting to REVERSE (R) while your vehicle
is moving forward could damage the transmission.
The repairs would not be covered by your warranty.
Shift to REVERSE (R) only after your vehicle is
stopped.
Also, use REVERSE (R), along with the parking brake,
when turning off your engine and parking your
vehicle.
Five-Speed (VORTECŸ 4300 V6 and
4800 V8 Engines)
Here's how to operate your transmission:
FIRST (1):Press the clutch pedal and shift into
FIRST (1). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
You can shift into FIRST (1) when you're going less
than 20 mph (32 km/h). If you've come to a complete
stop and it's hard to shift into FIRST (1), put the
shift lever into NEUTRAL and let up on the clutch.
Press the clutch pedal back down. Then shift into
FIRST (1).
SECOND (2):Press the clutch pedal as you let up on
the accelerator pedal and shift into SECOND (2).
Then, slowly let up on the clutch pedal as you press the
accelerator pedal.
2-31

THIRD (3), FOURTH (4) and FIFTH (5):Shift into
THIRD (3), FOURTH (4) and FIFTH (5) the same way
you do for SECOND (2). Slowly let up on the clutch
pedal as you press the accelerator pedal.
To stop, let up on the accelerator pedal and press the
brake pedal. Just before the vehicle stops, press
the clutch pedal and the brake pedal, and shift to
NEUTRAL.
NEUTRAL:Use this position when you start or idle
your engine.
REVERSE (R):To back up, ®rst press down the clutch
pedal. Wait for the vehicle to stop moving and then,
shift into REVERSE (R). Let up on the clutch pedal
slowly while pressing the accelerator pedal.
Notice:Shifting to REVERSE (R) while your vehicle
is moving forward could damage the transmission.
The repairs would not be covered by your warranty.
Shift to REVERSE (R) only after your vehicle is
stopped.
Also, use REVERSE (R), along with the parking brake,
when turning off your engine and parking your
vehicle.
Six-Speed (VORTECŸ 8100 V8 and
DURAMAXŸ 6600 V8 Engines)
Here's how to operate your
transmission.
This six-speed pattern is unique to GM manual
transmissions. The transmission always repositions the
shift lever to NEUTRAL, which is located between
FOURTH (4) and FIFTH (5) gear.
To prevent unintentional gear selections, additional
force is required to move the shift lever into
REVERSE (R) or FIRST (1). Use FIRST (1) when trailer
towing, driving with payload in the pickup box or
launching on a grade. Otherwise, start in SECOND (2)
gear. Only shift into FIRST (1) when the vehicle has
stopped moving.
2-32

During the ®rst 500 miles (805 km) of vehicle use, start
the vehicle moving in FIRST (1) gear. This allows
the clutch components to wear-in properly.
FIRST (1):With the vehicle at a stop, release the
brake, press the clutch pedal and shift into FIRST (1).
Then, slowly let up on the clutch pedal as you press the
accelerator pedal. Only downshift into FIRST (1)
when the vehicle has come to a complete stop. If the
shift lever will not go into FIRST (1), put the lever
in NEUTRAL and let up on the clutch pedal to fully
engage the clutch. Press the clutch pedal again. Then,
shift into FIRST (1).
SECOND (2):With the vehicle at a stop, release the
brake, press the clutch pedal and shift into SECOND (2).
Then, slowly let up on the clutch pedal as you press
the accelerator pedal. With the vehicle moving, press the
clutch pedal and upshift into SECOND (2) from
FIRST (1) while applying light pressure to the right on
the shifter. Then, slowly let up on the clutch pedal
as you press the accelerator pedal. If you come to a
complete stop and the shift lever will not go into
SECOND (2), put the lever in NEUTRAL and let up on
the clutch pedal to fully engage the clutch. Press
the clutch pedal again. Then, shift into SECOND (2).THIRD (3):Press the clutch pedal and upshift into
THIRD (3). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
FOURTH (4), FIFTH (5) and SIXTH (6):Upshift into the
higher forward gears the same way as you do
THIRD (3). Slowly let up on the clutch pedal as you
press the accelerator pedal.
NEUTRAL:Use this position when you start or idle
your engine.
REVERSE (R):To back up, press the clutch pedal.
Wait for the vehicle to stop moving and then, shift
to REVERSE (R). Let up on the clutch slowly while
pressing the accelerator pedal. Also, use REVERSE (R),
along with the parking brake, when turning off your
engine and parking your vehicle.
2-33

Shift Speeds
{CAUTION:
If you skip a gear when you downshift, you
could lose control of your vehicle. You could
injure yourself or others. Don't shift down
more than one gear at a time when you
downshift.
Do not allow the engine rpm to overspeed and enter the
tachometer red lines. Engine overspeed occurs when
downshifting, or descending a grade, at too high a
vehicle speed. When going down steep grades, always
select a gear at least one position lower than you
would use on climbing a grade. This will allow the
vehicle's engine to provide some braking and help to
slow the vehicle as it goes down the grade. Monitor your
vehicle speed, acceleration and engine rpm while
applying the brakes as you go down the grade to ensure
you have complete control over the vehicle.If your engine speed drops below 600 rpm, or if the
engine is not running smoothly, you should downshift to
the next lower gear. When operating on slippery
surfaces, downshift at lower than normal vehicle speeds
to prevent the tires from slipping.
In bench seat equipped vehicles, move the tallest
beverage containers to the right cupholder to provide
additional clearance for the shift lever.
For vehicles equipped with a center console, the front
cup holder pulls out and turns 180É to provide additional
clearance between tall beverage containers and the
shift lever.
2-34