GMC Duramax Diesel 2015 Owner's Manual page 27

5-18 Instruments and Controls
Turn the MENU knob to the desired
PTO Standby Set 2 setting. Press
the MENU knob to select the
desired setting.
PTO TAP STEP SPEED
This feature is available if the
vehicle is configured for Stationary
Variable or Mobile PTO, and allows
the selection of the PTO tap step
speed.
Turn the MENU knob to the desired
PTO Tap Step Speed setting. Press
the MENU knob to select the
desired setting.
PTO SHUTDOWN TIME
This feature is available if the
vehicle is configured for Stationary
Preset or Stationary Variable PTO,
and allows the selection of the PTO
shutdown time.
Turn the MENU knob to the desired
PTO Shutdown Time setting. Press
the MENU knob to select the
desired setting.