New Holland 110 – TCU: Mid-Range Clutch Solenoid Failure

The Transmission Control Unit (TCU) has detected an electrical anomaly in the circuit for the mid-range clutch solenoid, indicating that the wiring or the solenoid itself has failed open or shorted to ground. This prevents the solenoid from correctly actuating the hydraulic valve that controls oil flow to the clutch, resulting in a failure to engage or disengage the medium range gears.

• T6000
• T7
• T4
• T5
• T8
• TS90
• TS100
• TS110
• TS115
• TS100A
• TS110A
• TS115A
• TS125A
• TS135A
• TM115
• TM190
• TL70
• TL100A
• M100
• M115
• M135
• M160
• 8160
• 8260
• 8360
• 8560
• TD5.85
• TD5.115
• B90B

1. 1

   Verify the fault code in the tractor's diagnostic menu to confirm 110 is the primary active issue, ruling out false codes triggered by low battery voltage.

2. 2

   Visually inspect the wiring harness leading to the transmission control valve block for chafing, cuts, pinched wires, or corrosion.

3. 3

   Disconnect the mid-range clutch solenoid connector and inspect the pins on both the harness and solenoid for corrosion or moisture. Clean with electrical contact cleaner if necessary.

4. 4

   Perform a resistance test on the solenoid pins using a multimeter. A reading of 'OL' (infinite resistance) indicates an internal open circuit, while near-zero ohms indicates a short circuit.

5. 5

   Test the solenoid for a short-to-ground by checking for continuity between each solenoid pin and the tractor's chassis ground (there should be no continuity).

6. 6

   Test the wiring harness for end-to-end continuity, short-to-ground (continuity to chassis), and short-to-power (voltage present with key on, engine off) to rule out harness failure.

1. 1

   Prepare machine for service

   Park the tractor on a level surface, engage the parking brake, disconnect the battery, and allow the tractor to cool down completely.

2. 2

   Locate the solenoid

   Find the mid-range clutch solenoid on the transmission control valve assembly, typically mounted on the side of the transmission housing. Remove any protective covers or the right-hand rear wheel if necessary for access.

3. 3

   Drain transmission fluid

   If the valve block location requires it, place a suitable container under the transmission drain plug and drain the hydraulic fluid to prevent a large spill.

4. 4

   Remove the faulty solenoid

   Thoroughly clean the area around the solenoid. Disconnect the electrical connector and use the correct size wrench to carefully unscrew and remove the cartridge-style solenoid from the valve block.

5. 5

   Install the new solenoid

   Lubricate the O-rings on the new solenoid with clean hydraulic fluid. Carefully screw it into the valve block, tighten to the manufacturer's specified torque (do not overtighten), and reconnect the electrical connector.

6. 6

   Reassemble and refill

   Reinstall any covers or wheels that were removed. Reinstall the drain plug and refill the transmission with the correct type and amount of hydraulic fluid as specified in the operator's manual.

7. 7

   Calibrate the transmission

   Access the tractor's service menu ('H' routines) and perform a transmission calibration routine. This allows the TCU to learn the engagement points of the new clutch component. Failure to calibrate can result in harsh shifting or further transmission faults.

8. 8

   Final system check

   Start the tractor, allow it to warm up, and check for fluid leaks. Clear any stored fault codes and shift through all ranges to ensure the repair was successful.