Case IH 2559 – Transmission Controller or UCM (Universal Control Module): ORPM and Ring sensor fault

The control module detects that there is no signal coming from the sensor, but it has also verified that 'short to 12 V' or 'short to ground' faults are not present. This typically points to an open circuit, a sensor that has failed internally, or an incorrect sensor air gap.

• Optum
• Case IH Puma 130 CVX
• Case IH Puma 165
• Case IH Puma 180
• Case IH Puma 195
• Case IH Puma 210
• Case IH Puma 225 CVX
• Case IH Magnum MX210
• Case IH Magnum MX230
• Case IH Magnum MX255
• Case IH Magnum MX285
• Case IH Farmall
• Case IH Luxxum

1. 1

   Verify that the tractor battery power supply has not been connected to an external power supply (like a jump box or external charger). If connected, disconnect it and test the system for normal operation.

2. 2

   Inspect the sensor wiring harness for an open circuit, broken wires, or disconnected/corroded plugs at the transmission housing.

3. 3

   Check the sensor air gap to ensure the sensor is seated at the correct depth, as an incorrect gap can cause a loss of signal.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to ensure no power is going to the controller.

2. 2

   Locate the Sensor

   Locate the ORPM / Transmission Speed Sensor on the transmission housing.

3. 3

   Test/Replace the Sensor

   If the wiring harness tests fine for continuity, remove the ORPM/Ring speed sensor. Install the new sensor. (Note: When installing threaded transmission speed sensors, ensure it is threaded to the correct depth/air gap to prevent signal loss or physical damage to the sensor tip).

4. 4

   Clear Codes

   Reconnect the battery. Use the tractor's diagnostic menu (e.g., the 'H8' or 'HC' menu on the steering controller/integrated control panel) or a diagnostic tool to clear the stored error codes from the EEPROM.

5. 5

   Test Operation

   Start the tractor and test the transmission system for normal operation to ensure the code does not return.