2006 GMC 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. 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. 4-98