GMC duramax diesel 2016 Supplement Manual page 77

76 Driving and Operating
Mobile PTO
Mobile Enable Conditions
In-Cab Operation Only
Requires programming with the GM
Service Tool.
1. The engine must be running.
2. PARK brake must be released.
3. Confirm that cruise control
is off.
4. Engine rpm must be less than
1500 rpm.
5. Shift the transmission to M1,
M2, or M3.
6. Tap the brake pedal and then
do not press the brake pedal.
7. Press and release the PTO
In-cab switch below the center
console. Then within
10 seconds press and release
the cruise control +/RES button
(The PTO indicator light will
blink slowly between button
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.
8. Once engaged, if additional
engine speed is desired, use
either the cruise control buttons
or the accelerator pedal to
temporarily adjust the engine
speed.
The cruise control +/RES
button can be used to tap up,
or if continuously held to
ramp up, to the desired
operating speed. The cruise
control -/SET button 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 3100 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, the cruise
control -/SET button would
be used to capture and
maintain 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.