Case IH 108 – Transmission Controller (TRANS): Master clutch solenoid or its wiring failed open or shorted to ground.

The controller has detected an electrical anomaly in the master clutch solenoid circuit. The circuit is either broken (open circuit) or the voltage is bleeding off to the chassis (shorted to ground), preventing the solenoid from actuating the master clutch properly.

• MX Magnum
• STX Steiger
• Case IH MX Magnum Series
• MX210
• MX230
• MX255
• MX285
• Case IH TG Series
• Case IH Puma Series
• Case IH Maxxum Series
• Case IH Steiger / STX Series

1. 1

   Inspect the wiring harness (Connector No. 35 on MX Magnum) for chafing, melted insulation, or pinch points between the transmission and the TRANS controller

2. 2

   Disconnect the solenoid and inspect the plug for moisture, corrosion, or pushed-back pins (moisture is a highly common cause)

3. 3

   Using a multimeter, measure the resistance across the pins of the master clutch solenoid coil to check for an internal open circuit or a dead short to the housing

4. 4

   Test the wiring harness from the solenoid connector back to the Transmission ECU for continuity and ensure none of the wires are shorted to the tractor frame

1. 1

   Preparation

   Park the tractor on a level surface, engage the parking brake, and turn off the engine. Relieve any residual hydraulic pressure in the transmission system.

2. 2

   Locate the Solenoid

   Locate the master clutch solenoid on the transmission powershift valve mounting plate.

3. 3

   Removal

   Disconnect the electrical connector. Remove the retaining nut or bolt holding the solenoid coil/cartridge in place. Carefully pull the solenoid cartridge out of the valve body.

4. 4

   Inspection

   Inspect the valve bore for any burrs, scoring, or debris that could have caused the valve to stick.

5. 5

   Installation

   Lubricate the O-rings on the new master clutch solenoid with clean Case IH Hy-Tran hydraulic fluid. Insert the new solenoid into the bore and secure it with the retaining hardware.

6. 6

   Reconnection

   Plug the electrical connector back in, ensuring the locking tab clicks into place.

7. 7

   Calibration

   Clear the fault codes using the tractor's diagnostic display. Depending on the model, you may need to perform a transmission clutch calibration procedure via the AFS display to ensure the new solenoid engages the master clutch smoothly.