Case IH 56025 – Transmission Controller (TRANS): 1R Valve Coil circuit is shorted to 12 volts when the valve is ON.

This code triggers when the 1R clutch solenoid coil is commanded ON, but the transmission controller detects that the voltage on the low side of the coil is higher than expected. Possible failure modes include an internally shorted 1R clutch solenoid coil, wiring shorted to 12V power, or a failed transmission controller.

• STX Steiger
• Puma Series
• Magnum Series

1. 1

   Locate the 1R clutch solenoid on the transmission valve block and the transmission controller (typically underneath the fuse/relay panel in the cab).

2. 2

   Visually inspect the wiring harness between the 1R clutch solenoid and the transmission controller for chafing, melted insulation, or pinched wires that could cause a short to a 12-volt power source.

3. 3

   Disconnect the 1R clutch solenoid and use a multimeter to test the coil's resistance to check if the coil is internally shorted.

4. 4

   With the solenoid and controller disconnected, probe the harness to verify if the circuit is shorted to power.

5. 5

   If the solenoid tests within spec and the wiring harness shows no shorts to power, check the transmission controller as it is likely the point of failure.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to ensure safety while working on the transmission electrical circuits.

2. 2

   Repair Wiring

   If a short to 12V is found in the harness, repair the damaged section of the wire or replace the transmission wiring harness.

3. 3

   Replace Solenoid

   If the 1R clutch solenoid coil is internally shorted, remove the retaining hardware on the transmission valve block, extract the faulty solenoid, and install the replacement. Ensure the O-rings are seated properly and plug the connector back in.

4. 4

   Replace Controller

   If diagnostics point to a failed transmission controller, remove the paneling to access the module under the fuse/relay panel, disconnect the harnesses, and swap the module.

5. 5

   Clear Codes

   Reconnect the battery and turn the key ON. Access the 'Trans Setup' menu on the cab display to retrieve, record, and clear the fault codes.

6. 6

   Recalibrate

   A transmission calibration must be performed after replacing transmission solenoids or the controller. Use the PROG and DECR keys on the display to navigate the Trans Setup menu and complete the calibration process.