Case IH TMF167 – TMF: Current Detected When PTO Driver Is Off

The Tractor Multi-Function (TMF) controller is sensing electrical current in the PTO solenoid circuit even when the command to activate the PTO is not present. This indicates an unintended electrical pathway, such as a short circuit, is energizing the circuit. An active TMF167 fault may cause the system to disable the PTO to protect the powertrain.

• MX80C
• MX90C
• MX100C
• MX100
• MX110
• MX120
• MX135
• MX150
• MX170
• Magnum 215
• Magnum 245
• Magnum 275
• Magnum 305
• Magnum 335

1. 1

   Visually inspect the wiring harness leading to the PTO solenoid for signs of damage, chafed or melted insulation, pinched wires, or corrosion.

2. 2

   Disconnect the wiring harness from the PTO solenoid and examine the connector terminals for damage, corrosion, or moisture. Clean the connectors and ensure a secure fit.

1. 1

   Isolate the component

   Disconnect the wiring harness from the PTO solenoid to separate the solenoid from the rest of the circuit.

2. 2

   Check for short to power

   With the PTO solenoid disconnected and the tractor's key in the 'ON' position (engine off), use a multimeter to measure the voltage between the ground and the power pin in the wiring harness connector that leads back to the TMF controller. The expected result is 0 volts. If voltage is present, this indicates a short circuit in the wiring harness (contact with another power source), and the harness must be repaired or replaced.

3. 3

   Test the PTO solenoid

   If there is no voltage in the harness (wiring is good), measure the resistance between the two terminals of the PTO solenoid. A typical PTO solenoid should have a resistance of approximately 8.5 - 9.7 ohms. If the reading is significantly outside this range, indicating an open or shorted coil, replace the faulty solenoid.

4. 4

   Final verification

   After repairing the wiring or replacing the solenoid, clear any active fault codes. Operate the tractor and the PTO system to confirm that the fault does not return. A PTO calibration may be necessary after repairs.