Scan Tool Data Definitions Disengage or Inhibit Reasons

Power Take-Off (PTO) Control Module

The power take-off module (PTOM) disengages / inhibits power take-off for various reasons. The PTOM disengage / inhibit reasons are available in the scan tool for display when the PTOM disengages / inhibits power take-off. When a power take-off disengagement / inhibit occurs, be sure to view the PTOM data parameters. Also, when applicable, observe the driver information center (DIC) for additional requests, in order to engage PTO.

These Scan Tool Data Definitions contain a brief description of the PTO disengage parameters available on the scan tool for display. One of the following conditions must be present in order for a disengagement / inhibit parameter to be displayed:

Brake: This reason displays if the brake signal from either the ECM or BCM via serial data to the PTOM was invalid. Or this message would also display, if the DIC requested the driver to tap the brake pedal.

Clutch: This reason displays if the DIC requested the driver to either tap or release the clutch.

Cruise: This reason displays if the DIC requested the driver to disengage cruise control, or if cruise was engaged during mobile PTO operation.

DTC Present: This reason displays if there is a DTC present that either disengaged or inhibited PTO engagement.

Eng. Not Running: This reason displays if the engine was not running at the time of the PTO request for engagement.

Engine Speed: This reason displays if the engine speed signal from the ECM was either invalid or degraded. Or this message would also display, if the DIC requested the driver to reduce the engine speed.

High Speed: This reason displays if the PTOM disengaged PTO due to the engine RPM going higher than the upper set limit.

In Gear: This reason displays if the DIC displayed that the transmission is in gear, or if the transmission was shifted out of the Park or Neutral position during PTO operation.

Invalid Signal: This reason displays if one of the following input signals is invalid: clutch position, brake signal from the BCM, brake signal from the ECM, transmission gear position, vehicle speed, engine torque signal, no driven wheel speed signal, fuel level signal, or low oil pressure signal.

Low Speed: This reason displays if the PTOM disengaged PTO due to the engine RPM going lower than the lowest set limit.

None: This reason displays when there is no current reason stored or if a new PTOM was installed.

Not Normalized: This reason displays if the engine speed status signal from the ECM is not normal.

Not Pass: This reason displays if there is a DTC present that either disengaged or inhibited PTO engagement.

Park Brake: This reason displays if the DIC requested the driver to set the park brake, or if the park brake was released during PTO operation.

Release Brake: This reason displays if the DIC requested the driver to release the park brake, or if the park brake was set during mobile PTO operation.

Shutdown: This reason displays if the remote shutdown switch was activated from the upfitted remote switch assembly.

Speed Range: This reason displays one of the following conditions occurred: engine RPM error between the PTO requested RPM and actual RPM was too large, ECM inhibited PTO to control engine RPM, or PTO control was overridden by the accelerator pedal.

Switch: This reason displays if the PTO in-cab switch was either stuck or invalid.

Trans.: This reason displays if the transmission estimated gear signal from the TCM was invalid.

Trans. Torque: This reason displays if the transmission estimated gear signal from the ECM was invalid, or if the PTO requested torque was higher than the upper limit.

Vehicle Speed: This reason displays if the DIC requested the driver to reduce the vehicle speed.

Wheel Speed: This reason displays if the vehicle speed signal from the ECM was invalid.

Scan Tool Data Definitions Power Take-Off

The Scan Tool Data Definitions contains a brief description of all power take-off (PTO) related parameters available on the scan tool inside the PTO module (PTOM).

End Model Part Number: The scan tool displays the part number of the PTOM.

Engine Speed: The scan tool displays 0 to 9,999 RPM. The engine control module (ECM) monitors the crankshaft position (CKP) signal circuit in order to determine the engine RPM.

Ignition 1 Signal: The scan tool displays Volts. This is the voltage at the B+ input of the PTOM.

PTO Disengage Reason: The scan tool displays the last reason why the PTO was disengaged. Refer to the Scan Tool Data Definitions (Disengage or Inhibit Reasons) for descriptions.

PTO Indicator: The scan tool displays On or Off. The PTOM monitors the signal circuit of the PTO switch. A closed switch is displayed as On.

PTO Inhibit Reason: The scan tool displays the last reason why the PTO system was inhibited. Refer to the Scan Tool Data Definitions (Disengage or Inhibit Reasons) for descriptions.

PTO In Cab Switch: The scan tool displays PTO Off, PTO On, Set 1, Set 2, No Action, Invalid, or Indeterminate. The PTOM monitors the signal circuit of the PTO switch.

PTO In Cab Switch A: The scan tool displays %. The PTOM monitors the mode select A circuit and displays the current percentage.

PTO In Cab Switch B: The scan tool displays %. The PTOM monitors the mode select B circuit and displays the current percentage.

PTO In Cab Switch C: The scan tool displays %. The PTOM monitors the mode select C circuit and displays the current percentage.

PTO Option: The scan tool displays Enhanced, Disable, Preset, Variable, Mobile, or Fast Idle. This is the current state of the PTO system.

PTO Relay Indicator: The scan tool displays On or Off. This is the current state of the PTO relay.

PTO Remote Accelerator Sensor (If Equipped): The scan tool displays %. If equipped, the ECM sends a serial data message to the PTO module regarding the status of the PTO remote accelerator sensor.

PTO Remote Switch Status: The scan tool displays PTO Off, PTO On, Set 1, Set 2, No Action, Invalid, or Indeterminate. The PTOM monitors the signal circuit of the PTO remote switch.

PTO Status: The scan tool displays Disabled, Standby Disabled, Standby Pending, PTO Standby, PTO Active, Reserved, PTO Set, PTO Coast, Reserved, PTO Accelerate, Shutdown, or No Action. This is the current status of the PTO system.

Requested Engine Speed: The scan tool displays the requested RPM.

Software Part Number: The scan tool displays the software part number.

Vehicle Speed: The scan tool displays 0 to 150 km/h (93.2 mph). The ECM monitors the vehicle speed sensor signal circuit in order to calculate the vehicle speed for display. The ECM sends a serial data message to the PTOM regarding the current vehicle speed.