New Holland TMF 123 – TMF (Tractor Multi-Function) Controller: Aux 1st Lower Coil solenoid shorted to 12 volts

The controller has detected an electrical short circuit to a 12-volt power source (battery voltage) on the circuit responsible for controlling the lower (or retract) solenoid coil of the #1 auxiliary hydraulic remote valve.

• TG215
• TG245
• TG275
• TG305
• T8010
• T8020
• T8030
• T8040
• T8050
• T9000 Series

1. 1

   Visually inspect the auxiliary wiring harness from the TMF controller to the #1 auxiliary remote valve block for chafed insulation, pinched wires, or melted loom.

2. 2

   Disconnect the electrical connector at the Aux 1 lower solenoid and inspect pins for corrosion, water intrusion, or damage.

3. 3

   Perform a harness voltage test: With the solenoid disconnected and key ON, probe the harness-side connector. If 12 volts is present uncommanded, the harness is shorted to power.

4. 4

   Perform a coil resistance test: Measure resistance across the pins of the Aux 1 lower solenoid coil and compare to a known good coil (e.g., Aux 2). Zero or significantly lower resistance indicates an internally shorted coil.

1. 1

   Turn off the tractor, remove the key, and disconnect the battery to prevent electrical damage during repair.

   Turn off the tractor, remove the key, and disconnect the battery to prevent electrical damage during repair.

2. 2

   Relieve any residual hydraulic pressure in the system.

   Relieve any residual hydraulic pressure in the system.

3. 3

   Locate the #1 auxiliary remote valve section at the rear hydraulic stack.

   Locate the #1 auxiliary remote valve section at the rear hydraulic stack.

4. 4

   Disconnect the wiring harness connector from the lower solenoid coil.

   Disconnect the wiring harness connector from the lower solenoid coil.

5. 5

   If the harness is shorted: Trace the wiring back to the TMF controller. Locate the damaged section of the harness and repair the wires using weather-sealed butt connectors, or replace the auxiliary harness entirely if the damage is extensive.

   If the harness is shorted: Trace the wiring back to the TMF controller. Locate the damaged section of the harness and repair the wires using weather-sealed butt connectors, or replace the auxiliary harness entirely if the damage is extensive.

6. 6

   If the solenoid coil is internally shorted: Remove the retaining nut at the end of the solenoid cartridge.

   If the solenoid coil is internally shorted: Remove the retaining nut at the end of the solenoid cartridge.

7. 7

   Slide the faulty electromagnetic coil off the valve stem.

   Slide the faulty electromagnetic coil off the valve stem. (Note: You usually do not need to open the hydraulic system or remove the valve cartridge just to replace the coil).

8. 8

   Slide the new replacement coil onto the stem and secure it with the retaining nut.

   Slide the new replacement coil onto the stem and secure it with the retaining nut.

9. 9

   Reconnect the electrical connector to the new coil.

   Reconnect the electrical connector to the new coil.

10. 10

    Reconnect the battery, start the tractor, and clear the stored TMF 123 fault code.

    Reconnect the battery, start the tractor, and clear the stored TMF 123 fault code.

11. 11

    Actuate the #1 auxiliary remote to verify proper operation and ensure the code does not return.

    Actuate the #1 auxiliary remote to verify proper operation and ensure the code does not return.