New Holland TRANS 112 – TRANS: Reverse clutch solenoid or its wiring failed open or shorted to ground

The transmission controller continuously monitors the current draw from the reverse clutch solenoid circuit. If the current draw falls below a specific limit, the controller determines that the circuit is either open or shorted to ground. If the problem is temperature-sensitive, it often indicates that the solenoid coil is beginning to fail internally.

• New Holland TG Series (TG210, TG230, TG255, TG285)
• New Holland T8000 Series (e.g., T8040)
• New Holland T9000 Series

1. 1

   Remove the controller cover from the rear of the tractor and visually inspect the wiring harness running from the transmission controller toward the solenoids located under the cab for any obvious chafing, breaks, or damage.

2. 2

   Perform a harness resistance test (open circuit check) by disconnecting connector C355 from the transmission controller and measuring resistance between cavity 5 and cavity 2 on the wiring harness side (should be approximately 10 ohms). If dramatically higher, check the harness first; if intact, the open is likely inside the solenoid.

3. 3

   Perform a harness short-to-ground test by measuring resistance between cavity 5 of connector C355 and chassis ground, then cavity 2 and chassis ground. If either reading is less than a few ohms, inspect the wire for damage between the reverse clutch solenoid and the transmission controller.

4. 4

   If the harness tests fine, lift the cab to access the transmission solenoids, disconnect the reverse clutch solenoid connector (C034), and measure resistance directly between pin 1 and pin 2 (should be around 10 ohms). If dramatically higher, the coil failed open; if 10 ohms, check if the coil is internally shorted to the solenoid case.

1. 1

   Secure the Machine

   Park the tractor on a level surface, engage the parking brake, and turn off the engine.

2. 2

   Access the Solenoids

   Depending on the tractor model, you may need to lift the cab or remove access panels to reach the transmission control valve body where the solenoids are mounted.

3. 3

   Repair Wiring (If Applicable)

   If the diagnostic tests revealed a short or open in the wiring harness, locate the damaged section of the wire between the transmission controller (Connector C355) and the solenoid (Connector C034). Splice and repair the wire using weather-resistant connectors, or replace the harness section if heavily damaged.

4. 4

   Replace the Solenoid (If Applicable)

   If the solenoid failed the resistance test (open coil or shorted to case), clean the area around the proportional valve, disconnect the electrical connector, and unbolt and remove the solenoid from the transmission valve body. Install the new solenoid, ensuring any O-rings or seals are properly seated and lubricated with clean transmission fluid. Torque the mounting bolts to OEM specifications and reconnect the electrical connector.

5. 5

   Reassembly and Testing

   Lower the cab or reinstall access panels. Clear the fault codes from the transmission controller and test-drive the tractor in reverse to ensure proper clutch engagement and verify that TRANS 112 does not return.