Case IH 54272 – PTO Controller: PTO Shaft Overspeed Detected

This condition occurs when the system detects that the Power Take-Off (PTO) shaft is rotating at a speed that exceeds its safe or commanded operational limit.

• MX Magnum
• MX Magnum Series
• MX180
• MX200
• MX210
• MX220
• MX230
• MX240
• MX255
• MX270
• MX285
• TG Series
• TG210
• TG230
• TG255
• TG285
• MXM/TM series

1. 1

   Verify that the two PTO sensors (the PTO shaft speed sensor and the PTO dual speed/shaft size sensor) are properly connected. Ensure connectors C145 and C336 have not been installed in reverse.

2. 2

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

3. 3

   Check wiring harness continuity from Pin 10 of the PTO controller connector C056 to Pin A of connector C145.

4. 4

   Check wiring harness continuity from Pin 12 of connector C056 to Pin A of connector C146, and to Pin A of C336.

5. 5

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

6. 6

   Remove the controller cover from the rear of the tractor and check the wire/connections between the alternator terminal 'W' and the PTO controller pin C056-1 for an open circuit.

1. 1

   Locate the PTO speed sensors

   Locate the PTO speed sensors, which are typically mounted at the top rear of the transmission/PTO housing.

2. 2

   Inspect the wiring harness and connectors

   Inspect the wiring harness and connectors (C145, C146, C336, C056) for visible damage, corrosion, or loose pins.

3. 3

   Swap connectors if reversed

   If connectors C145 and C336 are plugged in backward, swap them to their correct positions.

4. 4

   Perform resistance test

   Using a multimeter, perform the 3 K Ohm resistance test on both the PTO shaft speed sensor and the dual speed sensor.

5. 5

   Replace faulty sensor

   If either sensor fails the resistance test, remove the faulty sensor and install a replacement.

6. 6

   Repair wiring harness

   If the sensors test good but the continuity checks fail, locate and repair the open circuit or short in the wiring harness between the PTO controller and the sensors (or the alternator 'W' terminal).

7. 7

   Clear fault codes and test

   Clear the fault codes from the system memory and test the PTO operation to ensure the overspeed code does not return.