New Holland 167 – TMF: Current Detected When PTO Driver Is Off

The system is detecting electrical current flowing through the Power Take-Off (PTO) driver circuit even though the controller has commanded the PTO to be in the "OFF" state. This indicates that voltage is bypassing the normal switching logic. This is typically caused by a short-to-power (12V) in the wiring harness between the controller and the PTO solenoid, a failed PTO solenoid, or an internal hardware failure within the controller itself.

• T6010
• T6020
• T6030
• T6040
• T6050
• T6060
• T6070
• T6080
• T7
• T8
• TS90
• TS100
• TS110
• TS115
• 5640
• 6640
• 7740
• 7840
• 8240
• 8340
• 8670
• 8770
• 8870
• 8970
• 8670A
• 8770A
• 8870A
• 8970A
• TD5
• Boomer 3040
• Boomer 3045
• Boomer 3050
• Case Farmall
• Powerstar

1. 1

   Visually inspect the wiring harness leading to the PTO solenoid for chafing, melting, or corrosion, especially where it rubs against the frame

2. 2

   Inspect electrical connectors for the PTO solenoid and TMF controller for corrosion, bent or spread pins, and moisture intrusion

3. 3

   Isolate the circuit by disconnecting the PTO solenoid and clearing fault codes to see if code 167 returns (this determines if the short is in the wiring harness or the solenoid itself)

1. 1

   Prepare machine for service

   Ensure the tractor is on a level surface, the parking brake is engaged, the engine is off, and the key is removed before beginning any electrical tests.

2. 2

   Locate components

   Identify the TMF controller and the PTO engagement solenoid. The solenoid is typically located on the PTO valve assembly at the rear of the tractor.

3. 3

   Test PTO solenoid resistance

   Disconnect the solenoid's electrical connector. Measure resistance between the two pins on the solenoid. A normal reading is typically 7-9 ohms. Infinite resistance (open circuit) or near-zero resistance (short circuit) indicates a faulty solenoid. Note: If the solenoid contains a diode, reverse the meter leads to verify an open circuit in both directions.

4. 4

   Test wiring harness for shorts

   If the solenoid tests good, disconnect the relevant connector at the TMF controller. Test for a short to ground by checking continuity between the signal wire pin at the solenoid connector and a clean chassis ground (there should be no continuity). Test for a short to power by turning the key on and checking for DC voltage on the signal wire at the solenoid connector (there should be no voltage when the PTO switch is off).

5. 5

   Repair wiring or replace solenoid

   If the PTO solenoid failed the resistance test, replace it with a new OEM part. If the wiring harness is shorted, trace the harness to find the damage, repair it, and ensure it is properly insulated and secured away from sharp edges or heat sources. Reconnect all components, clear fault codes, and test operation.