RPT 001890.31 – PTO Shaft Spline Identifier Switch, Malfunction

RPT 001890.31 (RPT 1890.31)

Code: 001890.31

Shortcode: 1890.31


This diagnostic trouble code, RPT 001890.31, is generated when the RPT control software detects a change in the rear PTO spline while the rear PTO is on. This indicates a malfunction in the PTO shaft spline identifier switch or associated components.


When this error is detected, the functionality of the rear PTO is significantly limited or entirely non-functional, affecting the operation of the connected implement.


Inspect PTO Shaft Spline Identifier Switch:

  • Check the PTO shaft spline identifier switch for any visible damage or disconnections.
  • Ensure the switch is securely mounted and connected properly.

Check Wiring and Connections:

  • Inspect the wiring and connections related to the PTO shaft spline identifier switch for signs of damage, corrosion, or loose connections.
  • Repair or replace any damaged components.

Test Switch Functionality:

  • Use diagnostic tools to test the functionality of the PTO shaft spline identifier switch.
  • Ensure the switch is transmitting accurate data to the control software.

Update Control Software:

  • Ensure that the control software is updated to the latest version.
  • Apply any available patches or updates that address switch malfunction issues.

Consult Technical Support:

  • If the problem persists, consult with technical support or the equipment manufacturer for further assistance.
  • Provide detailed error logs and diagnostic reports to aid in troubleshooting.

Monitor PTO System Performance:

  • After addressing the issue, monitor the rear PTO system to ensure it operates correctly.
  • Keep detailed records of any further errors or irregularities to assist in ongoing troubleshooting.


A malfunction in the PTO shaft spline identifier switch can cause significant disruptions in the PTO system’s operation. Regular inspections and maintenance of the PTO system and its electrical components can help prevent such problems.

Control Units: John Deere

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