Case IH 56023 – Transmission Controller (TRANS): 1F Valve Coil circuit is shorted to 12 volts when the valve is ON.

Triggered when the transmission controller turns on the 1F clutch solenoid coil, but the voltage on the low side of the coil is higher than expected, indicating a short to power (12V) somewhere in the circuit.

• STX Steiger
• STX Steiger Series
• MX Magnum Series
• Puma Series
• CS 150

1. 1

   Test the 1F clutch solenoid coil resistance by disconnecting connector C029 and measuring between cavity A and B (expected: 9.4-11.4 ohms at 40°F, 10.3-12.7 ohms at 80°F, 11.2-13.8 ohms at 120°F). Lower resistance indicates an internally shorted coil.

2. 2

   Visually and electrically inspect the wiring harness between the 1F solenoid and the transmission controller. Test for continuity to a 12V power source to confirm if the wire is shorted to power.

3. 3

   Evaluate the transmission controller if the solenoid coil resistance is within specification and the wiring harness shows no shorts to power.

1. 1

   Resolve the Short

   If the wiring harness is shorted to power, repair or replace the damaged section of the harness. If the 1F clutch solenoid coil failed the resistance test, replace the solenoid coil. If both the wiring and coil are good, replace the transmission controller.

2. 2

   Clear Codes

   Access the Trans Setup Menu on the tractor's display to retrieve, record, and clear the fault codes. The code must be cleared before calibration is possible.

3. 3

   Recalibrate Transmission

   After replacing transmission components or clearing codes, perform a transmission calibration. Ensure the inching pedal is in a valid range and follow the on-screen prompts in the Trans Setup menu to complete the fill process and calibration.