PTH 000191.00 – Transmission Output Shaft Speed Data Valid but Above Normal Operational Range – Most Severe Level

PTH 000191.00 (PTH 191.00)

Code: 000191.00

Shortcode: 191.00


This fault code indicates that the transmission output shaft speed is above the acceptable range while in hitch assist mode. This could be due to issues with the MFWD speed sensor, wiring problems, or malfunctions in the power train hydrostatic control unit.


When this error is detected, the equipment may experience unstable or unsafe operation. The system might shut down or enter a safe mode to prevent damage.


Inspect MFWD Speed Sensor (S33):

  • Check the speed sensor for proper operation.
  • Ensure the sensor is not damaged and is correctly positioned.
  • Verify all electrical connections are secure.

Test Power Train Hydrostatic Control Unit (PTH):

  • Perform diagnostic tests on the control unit to identify any faults.
  • Ensure all electrical connections to the control unit are tight and free from corrosion.

Check Wiring and Connections:

  • Inspect the wiring harness connected to the speed sensor for any signs of damage, wear, or loose connections.
  • Repair or replace any damaged wiring.

Update Control Software:

  • Ensure the control unit software is up-to-date with the latest fixes and improvements.

Consult Technical Support:

  • If the issue persists, contact technical support for further diagnostics and potential component replacement.

Monitor System Performance:

  • After addressing the issue, monitor the transmission system to ensure normal operation and that the fault does not reappear.


Regular inspection and maintenance of the speed sensor and associated wiring can prevent this fault. Consider environmental conditions such as extreme temperatures or exposure to moisture that can impact sensor performance.

Control Units: John Deere

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