Case IH 9071 – PTO Controller: The PTO is receiving no frequency from the Shaft Size Sensor on a two speed PTO configuration

The controller expects a signal to determine which PTO shaft size (and thus which speed profile) is installed, but it is receiving no data.

• MX Magnum
• Case IH MX180
• Case IH MX200
• Case IH MX210
• Case IH MX215
• Case IH MX220
• Case IH MX230
• Case IH MX240
• Case IH MX245
• Case IH MX255
• Case IH MX275
• Case IH MX285
• Case IH Magnum 215
• Case IH Magnum 235
• Case IH Magnum 275
• Case IH Magnum 280
• Case IH Magnum 290
• Case IH Magnum 305
• Case IH Magnum 310
• Case IH Magnum 315
• Case IH Magnum 335
• Case IH Magnum 340
• Case IH Steiger Series
• Case IH Quadtrac Series

1. 1

   Visually inspect the wiring harness routing to the PTO shaft speed sensor and the PTO dual speed (shaft size) sensor. Check for chafing or rodent damage, especially near the PTO and under the controllers on the back of the cab.

2. 2

   Check continuity from Pin 10 of connector C056 to Pin A of connector C145.

3. 3

   Check continuity from Pin 12 of connector C056 to Pin A of connector C146 to Pin A of C336.

4. 4

   Check continuity from Pin B of connectors C145 and C336 to the chassis ground.

5. 5

   Test the resistance of the speed sensor and shaft size sensor directly. Each sensor should measure approximately 3 K Ohms.

1. 1

   Repair Wiring

   If the visual inspection or continuity tests reveal chewed, broken, or shorted wires, strip back the damaged section and use weather-sealed butt connectors to splice in replacement wire. Retest the PTO engagement.

2. 2

   Locate the Sensor

   If the wiring is intact but the sensor failed the 3 K Ohm resistance test, locate the PTO shaft size/speed sensor. It is typically located near the PTO output shaft at the rear of the tractor, or on the top back of the transmission just under the draft arm cross tube.

3. 3

   Remove the Faulty Sensor

   Disconnect the electrical harness connector from the sensor. Unbolt/unscrew the sensor from its mounting port on the PTO housing/transmission.

4. 4

   Install the New Sensor

   Insert the new OEM sensor into the housing. Secure it to the specified torque (usually snug to prevent oil leaks) and reconnect the electrical harness.

5. 5

   Clear Codes and Test

   Turn the tractor on, clear the stored 9071 fault code from the PTO controller, and engage the PTO to verify that the shaft size is recognized and the PTO runs without shutting down.