PEC 013
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45
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12/20/13
PTO Mode Interlock Configurations
PTO interlocks provide an extra level of component protection. When in PTO Mode,
if one of the interlock conditions occurs, the engine control unit (ECU) reverts back to
normal driving mode. That means all the controls, logic and limits related to PTO
Mode instantly turn off. That includes limits related to minimum engine speed,
maximum engine speed, maximum vehicle speed, and maximum engine torque.
Other PTO Mode features, such as disabling the idle shutdown timer and logging
PTO Mode hours and fuel usage, will also turn off. At that point the engine speed is
controlled by the cab accelerator pedal (or goes to idle if there is no accelerator
pedal input). When the interlock trigger condition is removed, the engine returns to
PTO Mode automatically and the engine speed goes to the minimum engine speed
during PTO operation (N106). If the Resume/Decel button is the first button pressed
after entering PTO mode, the engine speed will increase to the last stored engine
speed prior to exiting PTO Mode. Otherwise the engine speed can be increased with
the Set/Accel button. When an interlock condition exists prior to mechanically
engaging the PTO, the engine will not enter PTO Mode until the interlock condition is
eliminated.
The engine does not enter PTO Mode when the PTO is mechanically engaged until
the engine speed is adjusted with a PTO Mode control switch. When the PTO is
mechanically engaged and prior to operating a PTO Mode control switch, none of the
controls, logic, and limits related to PTO Mode are active.
NOTE: When an interlock is triggered, it takes the engine out of PTO control
mode, but it does not mechanically disengage the PTO from the powertrain.
This section describes the available PTO Mode interlocks and the conditions that will
cause PTO Mode to not enable or cause the engine to drop out of PTO Mode.
The following interlocks are available:
Clutch Interlock (N078)
– Operating (depressing/actuating) the clutch pedal
will disengage PTO Mode.
Service Brake Interlock (N101)
– Operating (depressing/actuating) the
service brake pedal will disengage PTO Mode. This interlock is required for
mobile applications and/or UltraShift transmissions.
Parking Brake Interlock (N079)
– The parking brake must be engaged for
PTO Mode to be enabled.
Neutral Interlock (N089)
– The transmission must be in neutral for PTO Mode
to be enabled. This interlock feature is not available with Ultrashift
Transmissions.
Maximum Vehicle Speed Interlock (N080)
– The vehicle must not exceed a
preset speed or PTO Mode will not be enabled. While in PTO Mode, the
vehicle will not accelerate past the set
“PTO ON Interlock Vehicle Speed
Limit (N080).
” If the vehicle exceeds this set speed limit by more than 6 MPH
it will disengage PTO Mode. This would only happen in a downhill scenario
or similar situation where an external force or input causes the vehicle speed
to increase.
