2001 GMC SIERRA clutch

2-55
Cruise Control
With cruise control, you can
maintain a speed of about
25 mph (40 km/h) or more
without keeping your foot
on the accelerator.
This can really help on long trips. Cruise control does
not work at speeds below about 25 mph (40 km/h).
If you apply your brakes, or press the clutch pedal
(if equipped), the cruise control will disengage.CAUTION:

Cruise control can be dangerous where you
can't drive safely at a steady speed. So,
don't use your cruise control on winding
roads or in heavy traffic.

Cruise control can be dangerous on
slippery roads. On such roads, fast changes
in tire traction can cause needless wheel
spinning, and you could lose control.
Don't use cruise control on slippery roads.

2-56
Setting Cruise Control
CAUTION:
If you leave your cruise control switch on when
you're not using cruise, you might hit a button
and go into cruise when you don't want to. You
could be startled and even lose control. Keep the
cruise control switch off until you want to use
cruise control.
1. Move the cruise control switch to ON.
2. Get up to the speed you want.
3. Press in the SET button at the end of the lever and
release it.
4. Take your foot off the accelerator pedal.
United States Canada
The CRUISE light on the instrument panel will
illuminate when the cruise control is engaged.
Resuming a Set Speed
Suppose you set your cruise control at a desired speed
and then you apply the brake or press the clutch pedal
(if equipped). This, of course, disengages the cruise
control. But you don't need to reset it.
Once you're going about 25 mph (40 km/h) or more,
you can move the cruise control switch from ON to
R/A briefly.
You'll go right back up to your chosen speed and stay there.
If you hold the switch at R/A briefly, the vehicle will
keep going faster until you release the switch or apply
the brake. So unless you want to go faster, don't hold
the switch at R/A.

2-57
Increasing Speed While Using Cruise Control
There are two ways to go to a higher speed:

Use the accelerator pedal to get to the higher speed.
Press the SET button at the end of the lever, then
release the button and the accelerator pedal. You'll
now cruise at the higher speed.

Move the cruise switch from ON to R/A. Hold it
there until you get up to the speed you want, and
then release the switch. To increase your speed in
very small amounts, move the switch to R/A briefly.
Each time you do this, your vehicle will go
about 1 mph (1.6 km/h) faster.
Reducing Speed While Using Cruise Control

Press and hold the SET button at the end of the lever
until you reach the lower speed you want, then
release it.

To slow down in very small amounts, press the
SET button briefly. Each time you do this, you'll go
about 1 mph (1.6 km/h) slower.
Passing Another Vehicle While Using Cruise Control
Use the accelerator pedal to increase your speed. When
you take your foot off the pedal, your vehicle will slow
down to the cruise control speed you set earlier.Using Cruise Control on Hills
How well your cruise control will work on hills depends
upon your speed, load and the steepness of the hills.
When going up steep hills, you may want to step on the
accelerator pedal to maintain your speed. When going
downhill, you may have to brake or shift to a lower gear
to keep your speed down. Of course, applying the brake
takes you out of cruise control. Many drivers find this to
be too much trouble and don't use cruise control on
steep hills.
Ending Cruise Control
There are three ways to turn off the cruise control:

Step lightly on the brake pedal.

Step lightly on the clutch pedal (if equipped).

Move the cruise control switch to OFF.
Erasing Speed Memory
When you turn off the cruise control or the ignition,
your cruise control set speed memory is erased.

4-25
Q:What should I do if my vehicle stalls, or is about
to stall, and I can't make it up the hill?
A:If this happens, there are some things you should
do, and there are some things you must not do.
First, here's what you should do:

Push the brake pedal to stop the vehicle and
keep it from rolling backwards. Also, apply the
parking brake.

If your engine is still running, shift the transmission
to REVERSE (R), release the parking brake, and
slowly back down the hill in REVERSE (R).

If your engine has stopped running, you'll need
to restart it. With the brake pedal pressed and the
parking brake still applied, shift the transmission to
PARK (P) (or, shift to NEUTRAL (N) if your
vehicle has a manual transmission) and restart the
engine. Then, shift to REVERSE (R), release the
parking brake, and slowly back down the hill as
straight as possible in REVERSE (R).
As you are backing down the hill, put your left hand
on the steering wheel at the 12 o'clock position.
This way, you'll be able to tell if your wheels are
straight and maneuver as you back down. It's best
that you back down the hill with your wheels straight
rather than in the left or right direction. Turning the
wheel too far to the left or right will increase the
possibility of a rollover.
Here are some things you must not do if you stall,
or are about to stall, when going up a hill.

Never attempt to prevent a stall by shifting into
NEUTRAL (N) (or depressing the clutch, if you
have a manual transmission) to ªrev
-upº the
engine and regain forward momentum. This won't
work. Your vehicle will roll backwards very quickly
and you could go out of control.
Instead, apply the regular brake to stop the
vehicle. Then apply the parking brake. Shift to
REVERSE (R), release the parking brake, and
slowly back straight down.

Never attempt to turn around if you are about to
stall when going up a hill. If the hill is steep enough
to stall your vehicle, it's steep enough to cause you
to roll over if you turn around. If you can't make it
up the hill, you must back straight down the hill.

4-27
If you decide you can go down a hill safely, then try to
keep your vehicle headed straight down, and use a low
gear. This way, engine drag can help your brakes and
they won't have to do all the work. Descend slowly,
keeping your vehicle under control at all times.
CAUTION:
Heavy braking when going down a hill can cause
your brakes to overheat and fade. This could
cause loss of control and a serious accident.
Apply the brakes lightly when descending a
hill and use a low gear to keep vehicle speed
under control.
Q:Are there some things I should not do
when driving down a hill?
A:Yes! These are important because if you
ignore them you could lose control and have
a serious accident.
When driving downhill, avoid turns that take you
across the incline of the hill. A hill that's not too
steep to drive down may be too steep to drive across.
You could roll over if you don't drive straight down.

Never go downhill with the transmission in
NEUTRAL (N), or with the clutch pedal
pressed down in a manual shift. This is called
ªfree
-wheeling.º Your brakes will have to do
all the work and could overheat and fade.
Q:Am I likely to stall when going downhill?
A:It's much more likely to happen going uphill.
But if it happens going downhill, here's what to do.

Stop your vehicle by applying the regular brakes.
Apply the parking brake.

Shift to PARK (P) (or to NEUTRAL (N) with the
manual transmission) and, while still braking, restart
the engine.

Shift back to a low gear, release the parking brake,
and drive straight down.

If the engine won't start, get out and get help.

4-82 Power Take-Off (PTO) (If Equipped)
NOTICE:
If you have a PTO that will exceed 35 hp installed on
your vehicle, it could damage the transfer case or
transmission. When having a PTO installed on your
vehicle, make sure that it will not exceed 35 hp.
Before using a PTO, refer to the manufacturer's or
installer's instructions.
NOTICE:
Using a PTO while operating in one place before
the vehicle has reached normal operating
temperature can damage the transfer case or
transmission. If you will be using the PTO while
operating in one place, drive and warm up the
vehicle before using the PTO.
To engage a PTO on a vehicle with a
manual transmission:
1. Hold the clutch pedal down.
2. Set the parking brake.
3. Shift the transmission into NEUTRAL (N).
4. Engage the PTO. Refer to the manufacturer's
or installer's for instructions on electrically
engaged PTOs.
5. For mobile operations, shift the transmission into
the gear you want, apply the regular brakes and
release the parking brake. For stationary operations,
leave the parking brake applied.
6. Release the clutch and regular brakes as you
normally would. When the clutch is released,
the PTO will start.
7. Turn the PTO rotary switch to ON.
To engage a PTO on a vehicle with an
automatic transmission:
1. Engine speed must be less than 1000 rpm.
2. Turn the PTO rotary switch ON.

4-83
Using PTO speed control in Preset Mode
(Factory Setting):
1. Engage the PTO.
2. Select PARK (P) or NEUTRAL (N) range.
Apply the parking brake in NEUTRAL (N) is
selected. Torque Converter Clutch (TCC) lockup is
not available in NEUTRAL (N) and is available only
in PARK when engine speed is above 1100 rpm.
3. Make sure your foot is off the brake pedal
(and off the clutch on vehicles equipped with a
manual transmission). Select the desired engine
speed for PTO operation. Please read the following
Preset Mode information regarding operation.
Preset Mode: PTO speed control mode is used for
stationary applications. This mode provides a default
standby speed of 800 or 850 rpm (depending on the
engine/transmission combination) and two default PTO
control speeds which follow:

PTO Fast Idle Speed of 1250 rpm, or

PTO Fast Idle Resume Speed of 1700 rpm.
Standby speed (800/850 rpm) is not to be used as a
PTO control speed. Vehicles not equipped with cruise
control will not have the resume speed capability.Using PTO speed control in Variable Mode (Mobile):
1. Engage the PTO.
2. Vehicle speed must be greater than 5 mph for vehicles
equipped with gasoline engines or greater than 0 mph
for vehicles equipped with diesel engines.
3. Make sure your foot is off the brake pedal
(and off the clutch for vehicles equipped with a
manual transmission).
4. Select the desired engine speed (with the foot pedal)
and select SET on the PTO switch or with the
cruise control.
Using PTO speed control in Variable
Mode (Stationary):
1. Engage the PTO.
2. Vehicle speed must be less than 5 mph for vehicles
equipped with gasoline engines or at 0 mph for
vehicles equipped with diesel engines.
3. Make sure your foot is off the brake pedal
(and off the clutch for vehicles equipped with a
manual transmission).
4. Select the desired engine speed (with the foot pedal)
and select SET on the PTO switch or with the
cruise control.

5-18
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.
If a Tire Goes Flat
It's unusual for a tire to ªblow outº while you're driving,
especially if you maintain your tires properly. If air goes
out of a tire, it's much more likely to leak out slowly.
But if you should ever have a ªblowout,º here are a
few tips about what to expect and what to do:
If a front tire fails, the flat tire will create a drag that
pulls the vehicle toward that side. Take your foot off
the accelerator pedal and grip the steering wheel firmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you'd use in
a skid. In any rear blowout, remove your foot from
the accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but you can still steer. Gently
brake to a stop
-- well off the road if possible.
If a tire goes flat, the next part shows how to use your
jacking equipment to change a flat tire safely.