Case IH 517651-18 - DEC – DEC: PTO Rear Two-Speed Shaft Size/Speed Sensor Data Valid But Below Normal Operating Range

The system is receiving a valid signal from the PTO rear two-speed shaft size/speed sensor, but the frequency or voltage reading is lower than expected for the current operating state.

• MAGNUM AFS Connect
• Magnum 180
• Magnum 190
• Magnum 210
• Magnum 225
• Magnum 245
• Magnum 260
• Magnum 275
• Magnum 305
• Magnum 315
• Magnum 335
• Magnum 370
• MX150
• MX170
• MX180-MX305
• Puma 115
• Puma 185
• Puma 180-260 CVX
• Maxxum 100
• Maxxum 110
• Maxxum 115
• Maxxum 120
• Maxxum 125
• Maxxum 130
• Maxxum 140
• Optum 250
• Optum 270
• Optum 300
• Farmall 85C
• Farmall 95C
• Farmall 95U
• Farmall 105C
• Farmall 105U
• Farmall 115U

1. 1

   Verify if the PTO Shaft Speed Sensor and the PTO Shaft Size Sensor connections have been accidentally swapped (a common cause for PTO frequency faults).

2. 2

   Inspect the wiring harness between the Driveline Electronic Controller (DEC) and the PTO shaft size sensor for chafed wires or a poor connection at the 2-pin socket.

3. 3

   Remove and inspect the variable reluctance sensor tip for physical damage or excessive metallic debris accumulation, which can weaken the signal amplitude sent to the controller.

1. 1

   Locate sensor

   Locate the PTO speed/shaft size sensor, which is typically fitted within the rear PTO housing or on top of the transmission.

2. 2

   Disconnect connector

   Disconnect the 2-pin electrical connector from the sensor.

3. 3

   Clean area

   Clean the area around the sensor to prevent dirt from entering the transmission housing.

4. 4

   Remove sensor

   Remove the retaining bolt and carefully extract the sensor from the housing.

5. 5

   Install replacement

   Install the replacement PTO speed sensor and secure the retaining bolt.

6. 6

   Reconnect harness

   Reconnect the 2-pin wiring harness.

7. 7

   Verify repair

   Power up the tractor and clear the fault codes via the tractor monitor/instrument cluster. Engage the PTO to verify the speed is now accurately displayed on the corner post monitor without triggering a fault.