GMC CHEVROLET Silverado 6500HD 2019 Owner's Manual page 277

276 Driving and Operating
If OSIM pairing has been
configured, initiate OSIM stationary
variable operation:
1. With the engine running, shift
the vehicle into P (Park),
release the brake pedal, and
set the parking brake.
2. Confirm cruise control is off.
3. Confirm the hood is closed.
4. Press and release the PTO
in-cab switch. The PTO
indicator light will blink slowly.
5. Within 10 seconds, press and
release SET on the cruise
control. The PTO load relay will
engage and the PTO indicator
light will change to solid. The
engine speed will advance to
the PTO Standby Speed.
6. The desired operating speed
may be achieved by tapping up
and down with +RES and
SET on the cruise control.
The PTO load relay engages
immediately when the PTO
operation is initiated by the
switch input. The transmission
torque converter is unlocked.
The torque converter will lock
upon reaching stable PTO
Standby Speed (default = 900
rpm) so maximum power is
available.
The first elevated engine speed,
PTO Standby Speed, is not
intended as a working speed but
as a verification that the system
is active and ready to go to a
working speed.
The relay connections are made
at the PTO Upfitter Connector
located on the chassis frame
behind the cab.
The engine speeds can be
adjusted between the low of
PTO Standby Speed and the
high of PTO Max Engine speed
limits. Both values can be
modified from the factory default
settings with the GM Service
Tool. Based on the value chosen
for PTO Max Engine Speed, the
PTO menu in the center stack
may show speeds that are not
available.
Factory setting for the tap step is
100 rpm and the setting for ramp
rate is 150 rpm/sec. The default
value for tap step can be
modified via the Radio
Customization menu. The
default values for both tap step
and ramp rate can be changed
with the GM Service Tool.
The PTO load relay is enabled
as the factory default
programmed setting.
Refer to the service manual or
go to the GM Upfitter Integration
website www.gmupfitter.com for
details.