Case IH 517651-12 - DEC – TMF: PTO rear two-speed shaft size speed sensor - bad intelligent device or component

The code indicates a failure related to the PTO rear two-speed shaft size speed sensor, specifically flagging it as a bad intelligent device or component. The system cannot verify the shaft size or monitor the PTO RPM accurately.

• MAGNUM AFS Connect
• Maxxum Series
• MX80C
• MX90C
• MX100
• MX110
• Farmall Series
• C Series

1. 1

   Visual & Wiring Inspection: Verify that the sensor is actually faulty by checking the wiring harness and electrical connections for damage, corrosion, or a lack of power.

2. 2

   Signal Testing: Use a diagnostic tool (like Wintest) to check if the PTO is receiving frequency from the Shaft Size Sensor. When the PTO is activated, the PTO speed sensor value must equal the engine speed.

3. 3

   Multimeter Test: If the RPM values obtained are incorrect, intermittent, or not detected at all, test the sensor's resistance using a multimeter while the machine is stationary.

4. 4

   Mechanical Check: Ensure there is no visible PTO shaft slippage under load, which could trigger related PTO fault codes rather than a sensor failure.

1. 1

   Turn off the tractor engine and ensure any connected implements are safely grounded.

2. 2

   Locate the PTO speed sensor at the rear PTO housing.

3. 3

   Disconnect the electrical wiring harness from the sensor.

4. 4

   Remove the faulty sensor.

5. 5

   Install the new PTO speed sensor.

   Fitment Note: The sensor must be positioned precisely relative to the internal tone ring, so take care to set the depth/gap properly during installation.

6. 6

   Reconnect the wiring harness.

7. 7

   Clear the fault codes from the system.

8. 8

   Engage the PTO at various speeds and verify that the cab display shows steady RPM readings that match expected outputs.