Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
Driving and Operating 41
.Refer to the service manual or go to the
GM Upfitter Integration website
www.gmupfitter.com for details, advanced
programming features, and usage with a
removable pendant.
Variable PTO
Variable Enable Conditions–In-Cab
Operation
To enable PTO:
1. With the engine running, shift the vehicle into P (Park) and set the parking
brake. Do not press the brake pedal.
2. Press and release the PTO in-cab switch below the climate controls in the center
stack. The PTO indicator light will blink
rapidly until the PTO load relay becomes
engaged and will then be on steady. The
engine will advance to the PTO Standby
Speed.
3. Once PTO Standby Speed is reached, SET −and +RES on the cruise control can be
used to tap up and tap down the engine
speed. Factory setting for the tap step is
100 rpm and the setting for the ramp
rate is 150 rpm/sec. The GM Service Tool
can enable the capability to change the
default value for tap step via the Radio
Customization menu. The default values for both tap step and ramp rate can be
changed with the GM Service Tool. The
accelerator pedal is disabled, and cannot
be used to control PTO engine speed.
Variable Enable Conditions –Remote
Operation
This requires programming with the GM
Service Tool and the appropriate remote
switch panel provided by GM Upfitter.
1. Confirm that cruise control is off.
2. Set the parking brake and shift the transmission into P (Park).
3. Turn the engine off. Remove or place the key in the ignition off position. Lock the
vehicle, if desired.
4. The hood must be closed.
5. From outside the vehicle, press and release the Remote PTO Arm switch.
6. Within five seconds, open and close the Remote PTO Engine Start/Shutdown
switch.
7. The horn will chirp, and then engine starting will be automatically initiated.
The PTO system will then elevate engine
rpm to PTO Standby Speed and engage
the PTO load relay. Variable Enable Conditions
–Remote
Operation In-Cab Enable Starting Remote
Operation from In-Cab
This requires programming with the GM
Service Tool and remote switch panel
provided by GM Upfitter.
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.
5. The horn will chirp, the PTO load relay will engage, and the engine will advance
to the PTO Standby Speed.
The operator may exit the vehicle.
{Warning
If the key is in the ignition during
Remote PTO operation, the vehicle can be
shifted out of P (Park) by an
unauthorized operator. Even though PTO
will be disengaged, depending on PTO
Upfitter application, personal injury or
property damage may result from vehicle
movement. The operator must ensure (Continued)
Chevrolet/GMC 2.8L Duramax Diesel Engine Supplement (GMNA-Localizing-
U.S./Canada-14465442) - 2021 - CRC - 2/3/20
46 Driving and Operating
accumulate soot. The engine control system,
depending on the speed and load being
applied by the PTO, may not be able to
generate enough energy or adequate heat
needed to automatically clean or regenerate
the DPF. If manual regeneration is not
initiated, continued operation under
conditions that do not allow effective
regeneration or cleaning will eventually plug
the DPF and result in reduced power. The
ENGINE POWER IS REDUCED Driver
Information Center (DIC) message and
malfunction indicator lamp will be displayed,
and dealer service will be required to return
the vehicle to normal, full power operation.
To prevent this from occurring, frequently
monitor the vehicle during stationary PTO
operation, paying particular attention to any
horn chirps and/or the CLEAN EXHAUST
FILTER SEE OWNER MANUAL NOW DIC
warning messages. If the DIC message is
displayed during PTO operation, seeDiesel
Particulate Filter 019 for information on
how to clean or regenerate the DPF.PTO Operational Speed Control
Variable PTO operational speed control
provides the following functions:
Cruise Control SET− (In-Cab) or Remote PTO
Set 1 Switch
SET : Press and hold the accelerator to
obtain the desired engine speed, then press
and release SET− on the cruise control. The
current engine speed will be maintained.
This action can be repeated as desired to
capture a higher rpm value. The PTO set
speed cannot exceed 2900 rpm.
TAP DOWN : Press and release SET− on the
cruise control to reduce the engine speed by
increments of 100 rpm. The tap down
engine speed increments can be adjusted by
the GM Service Tool. The Service Tool can
enable the option for adjustment of tap
down engine speed increments through the
Radio Customization menu.
COAST : Press and hold SET− on the cruise
control to reduce the rpm at 150 rpm/sec
until the desired engine speed is reached or
until the initial PTO Standby Speed is
reached. In-Cab Cruise Control +RES or Remote PTO
Set 2 Switch
RESUME :
After a PTO set speed has been
met, a Resume Speed message is retained
after an application of the brake pedal.
Engine speed will reduce to basic idle speed.
The PTO indicator light will blink slowly
indicating the previous PTO set speed has
been retained in memory. Press and release
+RES on the cruise control to resume the
previous PTO set speed.
TAP UP : Press and release +RES on the
cruise control to increase the engine speed
by increments of 100 rpm (factory preset
value). The tap up engine speed increments
can be adjusted by the GM Service Tool. The
Service Tool can enable the option for
adjustment of tap up engine speed
increments through the Radio
Customization menu.
ACCEL : Press and hold +RES on the cruise
control to increase the rpm by 150 rpm/sec
until the desired engine speed is reached or
until the maximum allowable PTO set speed
is reached. Alternatively, the engine speed
acceleration can be adjusted through the
Radio Customization menu.
