Chevrolet GMC Duramax 2023 Manual page 38

For key access vehicles, turn the ignition
on and press the brake pedal. For keyless
access vehicles, hold the push button start
for two seconds. Press the brake pedal.
The PTO clutch disengages and the engine
returns to base idle speed.
Stationary Modes will also disengage if:
Vehicle movement is detected.
The parking brake is released.
The transmission is shifted out of
P (Park).
The ignition is cycled from on to off.
The PTO feedback signal is lost indicating
the load is disengaged if used. See
www.gmupfitter.com.
Cruise control becomes enabled.
Timed auto-engine shutdown: PTO must
be operational for this function to be
active.
The engine is shut down based on critical
engine or PTO system fault conditions:
This feature will shut down the engine
when PTO is operating if a critical engine
condition such as low oil, low oil pressure,
hot engine, hot transmission, low fuel,
or Diesel Particulate Filter regeneration is
detected by the vehicle system. If PTO
operation is continued when critical
engine conditions are present, a horn
chirp warning will occur after
30 60 seconds. The engine will shut
down two minutes after the horn
warning. The engine can be restarted
with the ignition key or with the Remote
PTO engine start controls or by push
button start. The horn warning and
engine shutdown will again occur if the
critical engine condition is still present.
Maximum engine torque limit has been
reached.
Resume memory speed is cleared for the
above actions.
When Remote PTO engine starting has been
initialized with the ignition key in the RUN
position, the shift lever will remain locked.
A shift out of P (Park) will not be allowed
while the engine is running and PTO is
active, until one of the following actions is
taken:
Press the brake pedal. PTO will disengage.
Engine will run at idle speed and shift
lever can be shifted from P (Park).
Press the PTO in-cab switch, only if the
PTO in-cab Remote Start/Stop feature is
enabled. This requires programming with
Driving and Operating
the GM Service Tool. PTO will disengage
and shift lever can be shifted from
P (Park).
Mobile Mode
To disengage PTO:
Press the brake pedal. The PTO system
releases control of engine speed, but the
PTO clutch remains engaged. The engine
will return to base idle unless the
accelerator pedal is pressed. The PTO
clutch remains engaged. The PTO
indicator light will flash slowly indicating
that a PTO set speed is still stored in
memory. Upon releasing the brake, the
factory default programming is for the
engine speed to remain at curb idle
awaiting an input from +RES on the cruise
control to restore engine rpm to the last
PTO set speed. The system can also be
programmed to return engine rpm to the
PTO Standby Speed setting.
Press on the cruise control. The engine
returns to base idle, but the PTO clutch
remains engaged. The PTO indicator light
will flash slowly indicating that a PTO set
speed is still stored in memory. Pressing
+RES on the cruise control will restore
engine rpm to the last PTO set speed.
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