tow GMC SIERRA 2005 User Guide

Passlock®
Your vehicle is equipped with the
Passlock®theft-deterrent system.
Passlock
®is a passive theft-deterrent system.
Passlock®enables fuel if the ignition lock cylinder is
turned with a valid key. If a correct key is not used or the
ignition lock cylinder is tampered with, fuel is disabled.
If the engine stalls and the security light ashes,
wait until the light stops ashing before trying to restart
the engine. Remember to release the key from
START as soon as the engine starts.
If the engine is running and the security light comes on,
you will be able to restart the engine if you turn the
engine off. However, your Passlock
®system is
not working properly and must be serviced by your
dealer. Your vehicle is not protected by Passlock
®at this
time. You may also want to check the fuse. See
Fuses and Circuit Breakers on page 5-122. See your
dealer for service.
In an emergency, call the GM Roadside Assistance
Center. SeeRoadside Assistance Program on page 7-5.
Starting and Operating Your
Vehicle
New Vehicle Break-In
Notice:Your vehicle does not need an elaborate
break-in. But it will perform better in the long run if
you follow these guidelines:
Keep your speed at 55 mph (88 km/h) or less for
the rst 500 miles (805 km).
Do not drive at any one speed — fast or
slow — for the rst 500 miles (805 km). Do not
make full-throttle starts.
Avoid making hard stops for the rst 200 miles
(322 km) or so. During this time your new
brake linings are not yet broken in. Hard stops
with new linings can mean premature wear
and earlier replacement. Follow this breaking-in
guideline every time you get new brake
linings.
Do not tow a trailer during break-in. SeeTowing
a Trailer on page 4-68for more information.
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Automatic Transmission Operation
If your vehicle is equipped with an automatic
transmission, it features an electronic shift position
indicator within the instrument panel cluster. This display
must be powered anytime the shift lever is capable of
being moved out of PARK (P). SeeFuses and
Circuit Breakers on page 5-122.
There are several different positions for your shift lever.
PARK (P):This position locks your rear wheels. It is
the best position to use when you start your engine
because your vehicle cannot move easily. If your vehicle
is equipped with the Allison Transmission
®, use
PARK (P) for stationary operation of the Power Takeoff
(PTO), if equipped. The Allison Transmission
®is
equipped with park pawl designed to hold the higher
weight of commercial medium duty trucks. Therefore, the
Allison Transmission
®uses larger parts than other
automatic transmission. These larger parts may
sometimes make a clunk noise when the selector lever
is moved from DRIVE (D) or REVERSE (R) to
PARK (P). This is normal and there is no damage
occurring during these shifts.
{CAUTION:
It is dangerous to get out of your vehicle if the
shift lever is not fully in PARK (P) with the
parking brake rmly set. Your vehicle can roll.
Do not leave your vehicle when the engine is
running unless you have to. If you have left the
engine running, the vehicle can move
suddenly. You or others could be injured. To
be sure your vehicle will not move, even when
you are on fairly level ground, always set your
parking brake and move the shift lever to
PARK (P). SeeShifting Into Park (P) (Automatic
Transmission) on page 2-49. If you are pulling
a trailer, seeTowing a Trailer on page 4-68.
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{CAUTION:
If you have four-wheel drive, your vehicle will
be free to roll — even if your shift lever is in
PARK (P) — 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) — not in
NEUTRAL. SeeShifting Into Park (P)
(Automatic Transmission) on page 2-49.
REVERSE (R):Use this gear to back up. If your vehicle
is equipped with the Allison Transmission
®, 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,
seeIf You Are Stuck: In Sand, Mud, Ice or Snow on
page 4-48.NEUTRAL (N):In this position, your engine does not
connect with the wheels. To restart when you are
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.
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DRIVE (D):This position is for normal driving. If you
need more power for passing, and you are:
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 will 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.
If your vehicle is equipped with the Allison
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.
The Allison Transmission
®uses a shift stabilization
feature to adjust the transmission shift schedule to the
current driving situation to reduce rapid upshifts and
downshifts. This shift stabilization feature is designed to
determine before making an upshift if the engine will
be able to maintain vehicle speed by analyzing
things such as throttle position, vehicle load, and hill
grade. If the shift stabilization feature determinesthat current vehicle speed cannot be maintained, the
transmission does not upshift and instead holds
the current gear. In some cases, this may appear to be
a hanging shift, however the transmission is operating
normally.
The Allison Transmission
®also uses adaptive shift
controls. Adaptive shift controls continually compares
key shift parameters to pre-programmed ideal shift
conditions. The Allison Transmission
®constantly makes
adjustments to improve vehicle performance according
to the way the vehicle is being used, such as with a
heavy load. During this adaptive shift controls process,
some shifts may feel different as the transmission
determines optimum settings for a particular shift.
By using shift stabilization and adaptive shift controls,
the Allison Transmission
®shift schedule is variable and
adjusts to how the vehicle is being used, providing
improved vehicle performance.
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.
2-28

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 will not 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 32°F (0°C) or colder, your
transmission is designed to shift differently. The
transmission uses a warm-up mode shift schedule until
the engine reaches normal operating temperature.
While the transmission is in warm-up mode it is normal
for transmission upshifts to be delayed or held longer.
This feature improves heater performance by giving
quicker vehicle warm-ups.Tow/Haul Mode
If your vehicle has an automatic transmission, it 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.
2-29

Tow/Haul is a feature on automatic transmission
equipped vehicles that assists when pulling a heavy
trailer or large or heavy load. Tow/Haul mode adjusts the
transmission’s shift pattern to reduce shift cycling,
providing increased performance, vehicle control, and
transmission cooling when towing or hauling heavy loads.
If your vehicle is equipped with an Allison
®transmission,
you may have both Tow/Haul mode and overdrive
disable. See “Tow/Haul Mode” underTowing a Trailer
on page 4-68for more information.
Grade Braking
(Allison Transmission®Only)
Grade braking uses the engine and transmission to slow
a loaded vehicle on hills in addition to using the
brakes, saving on brake wear and increasing vehicle
stability. The Allison Transmission
®, when sensing
the driver’s desire to slow down while driving downhill,
will automatically shift to the next lower gear range
to assist in slowing down the vehicle. Grade braking is
active and automatic both in Tow/Haul mode and
normal shift mode. Grade braking is more aggressive
when in Tow/Haul mode and can automatically downshift
to SECOND (2), which is different than grade braking
while in normal shift mode where automatic downshifts
are limited to FOURTH (4).The tachometer for both the diesel and gasoline engine
shows a dashed red zone and a solid red zone. The
dashed red zone indicates where a transmission
shift occurs for full engine power. When using grade
braking, the transmission’s shift point is adjusted to just
prior to the solid red zone, providing the benet of
additional engine braking.
Grade braking driving within the dashed red zone is
normal, both the diesel and gasoline engine have been
designed for this grade braking feature. Do not allow
the engine to go into the solid red zone. Apply the
vehicle’s brakes for a short time to slow down if you are
driving on a long hill and the tachometer needle
enters the solid red zone. SeeTowing a Trailer on
page 4-68for more information.
2-30

Overdrive Disable
(Allison®Transmission Only)
If your vehicle has an Allison Transmission®, you may
have the overdrive disable feature. The overdrive disable
feature prevents the transmission from shifting into
FIFTH (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.
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.
2-31

Manual Transmission Operation
Five-Speed
(VORTEC™ 6000 V8 Engine)
Here is 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 are going less
than 20 mph (32 km/h). If you have come to a complete
stop and it is 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.
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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 (VORTEC™ 8100 V8 and
DURAMAX™ 6600 V8 Engines)
Here is 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.
2-34

A 4WD indicator light will
illuminate when you shift
into four-wheel drive
and the front axle engages.
SeeFour-Wheel-Drive
Light on page 3-48.
Some delay between shifting and the indicator’s lighting
is normal.
Recommended Transfer Case Settings
Transfer Case Settings
Driving Conditions 2HI 4HI 4LO N
Normal YES
Severe YES
Extreme YES
Vehicle in Tow* YES
*SeeRecreational Vehicle Towing on page 4-62or
Towing Your Vehicle on page 4-62for further
information.An indicator light near the lever shows you the transfer
case settings:
2-Wheel High (2HI):This setting is used for driving in
most street and highway situations. Your front axle
is not engaged in two-wheel drive. This setting
also provides the best fuel economy.
4-Wheel High (4HI):Use 4HI when you need extra
traction, such as on snowy or icy roads or in most
off-road situations. This setting also engages your front
axle to help drive your vehicle. This is the best setting
to use when plowing snow.
{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P), or if you have a
manual transmission, even if you are in gear.
You or someone else could be seriously
injured. Be sure to set the parking brake
before placing the transfer case in NEUTRAL.
SeeParking Brake on page 2-48.
2-38