GMC 2006 Sierra 1500 Pickup Owner's Manual page 410

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.
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.
4-98
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.
Variable Mode: PTO speed control mode can be used
for both stationary and mobile applications. This mode
allows PTO to be controlled in a fashion similar to how
cruise control sets vehicle speed. The operator can set to
an rpm (between 800 and 2,200) with the cruise control
feature or with the SET position on the PTO switch. The
operator is then able to increase rpm in increments of
100, or "tap up" with the resume position on the cruise
control. The operator can also decrease rpm in
increments of 100 with the SET switch on the PTO or
the cruise control.
Vehicles not equipped with cruise control will not have
the "tap up" capability.