GMC 2.8L Duramax Diesel 2020 Manual page 54

5. Shift the transmission to M1,
M2, or M3.
6. Tap the brake pedal and then
do not press the brake pedal.
7. Keep the driver door closed.
The driver door can be kept
open if reconfigured using the
GM Service Tool. See
www.gmupfitter.com.
8. Press and release the PTO
in-cab switch below the climate
controls in the center stack.
Then within 10 seconds press
and release +RES on the
cruise control. The PTO
indicator light will blink slowly
between presses. The PTO
indicator light will then blink
rapidly until the PTO load
becomes engaged, and then
come on steady. The engine
speed will remain at the current
throttle setting or advance to
PTO Standby Speed,
whichever value is greater.
If the engine rpm is above
1500 rpm, the PTO relay will
not engage until the engine
rpm drops below 1500 rpm.
9. Once engaged, if additional
engine speed is desired, use
either the cruise control or the
accelerator pedal to temporarily
adjust the engine speed.
+RES on the cruise control
can be used to tap up, or if
continuously held to ramp
up, to the desired operating
speed. SET on the cruise
control can be used to tap
down or coast down if
continuously held to the
desired engine speed. Top
limit is PTO Max Engine
Speed, default 2100 rpm and
programmable to 2900 rpm.
Lower limit is PTO Standby
Speed, default 900 rpm with
program range from base
idle to 900 rpm.
The accelerator pedal can be
used to achieve the desired
speed. When the desired
speed is reached, SET on
the cruise control would be
used to capture and maintain
Driving and Operating
that speed. Normal tap up
and tap down can then be
used to fine tune the setting.
In Mobile PTO mode, the vehicle
speed achieved is the result of the
current engine speed requested and
the transmission gear range
selected. When the vehicle is
placed in M2 or M3, the vehicle will
upshift according to engine rpm set
point, and vehicle speed will
increase. To prevent upshifts and
maintain lower vehicle speeds,
place the vehicle in M1.
Mobile Enable Conditions
Operator Selectable In-Cab
Mode (OSIM)
This requires programming with the
GM Service Tool and specific
pairing mobile mode with either
stationary preset or variable.
Remote operation is not available.
See Mobile PTO previously in this
section.
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