GMC Sierra Classic 2007 Owner's Manual page 458

To use PTO speed control in Preset Mode
(Factory Setting) do the following:
1. Engage the PTO.
2. Select PARK (P) or NEUTRAL (N) range.
Apply the parking brake if NEUTRAL (N) is
selected. Torque Converter Clutch (TCC)
is not available in NEUTRAL (N) and is
available only in PARK (P) when engine speed
is above 1,100 rpm.
3. Make sure your foot is off the brake pedal
(and off the clutch on vehicles equipped
with a manual transmission).
4. Select the desired engine speed for PTO
operation. Read the following preset mode
information regarding operation.
Preset Mode: PTO speed control mode is used for
stationary applications. (PTO will remain engaged
while mobile in the preset mode, however PTO set
and resume speed controls will be inoperative.)
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:
1. PTO Set Speed of 1,250 rpm, or
2. PTO Resume Speed of 1,700 rpm.
458
Please note that the 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.
To use PTO speed control in variable mode (while
mobile) do the following:
1. Engage the PTO.
2. Vehicle speed must be greater than 5 mph.
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 by using the
foot pedal, and select SET on the PTO switch
or the cruise control.
To use PTO speed control in variable mode (while
stationary) do the following:
1. Engage the PTO.
2. Vehicle speed must be less than 5 mph.
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 by using the
foot pedal, and select SET on the PTO switch
or the cruise control.