Chevrolet Silverado 4500HD 2022 Manual page 261

260 Driving and Operating
Press the PTO in-cab switch. Load relay
disengages and the engine returns to
base idle. The PTO indicator light will turn
off, indicating the PTO load relay is
disengaged and the stored set speed has
been cleared from memory.
Mobile Mode will also disengage if:
PTO feedback input is lost. The engine
speed is returned to the PTO Standby
speed setting and the load is still
engaged. This is configurable with the GM
Service Tool.
Vehicle Speed exceeds Max Vehicle Speed.
Factory default setting = 94 km/h
(58 mph). PTO relay will re-engage and
advance to the last engine speed stored
in memory when both the Vehicle Speed
is reduced below 94 km/h (58 mph) and
the engine speed ramps down below the
maximum PTO engagement speed (1500
rpm factory default setting).
Engine Speed exceeds Max Engine Speed
for more than 15 seconds. Factory default
setting = 2100 rpm.
on the cruise control is pressed.
The parking brake is applied.
The shift lever is moved out of manual
shift selection, M1, M2, or M3.
Resume memory speed is cleared for the
above actions.
Although the PTO system attempts to limit
accelerator and PTO switch inputs to comply
with maximum speed and/or rpm
parameters, some vehicle operating
conditions such as downhill acceleration can
cause the vehicle speed or engine rpm to
exceed these limits. In those cases, the PTO
system may disengage.
Operator Selectable In-Cab Mode (OSIM)
To disable OSIM Stationary PTO:
Press and release the PTO in-cab switch.
To disable OSIM Mobile PTO:
Press and release the PTO in-cab switch.
Prolonged or Extended PTO Operation
When operating the vehicle in stationary
PTO mode, the Diesel Particulate Filter (DPF)
will continue to filter the exhaust and
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 clean or regenerate the DPF.
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 PTO operation, paying particular
attention to the CLEAN EXHAUST FILTER SEE
OWNER MANUAL NOW DIC warning
message. If the DIC message is displayed
during PTO operation, see Diesel Particulate
Filter 0 206 for information on how to clean
or regenerate the DPF.