Case IH 2547 – UCM (User Control Module) / Transmission Controller: No signal from ring sensor

The control module detects that no signal is coming from the ring speed sensor, but it has also verified that there are no "short to 12V" or "short to ground" faults present in the circuit.

• Optum
• Puma 165 CVX
• Puma 180 CVX
• Puma 195 CVX
• Puma 210 CVX
• Puma 225 CVX
• Magnum Series (CVT models)

1. 1

   Check for other error codes. If no other codes are present, proceed with diagnosing the ring sensor.

2. 2

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

3. 3

   Check the battery voltage on the instrument cluster. Start the engine and run it at 2000 rev/min to ensure the alternator is providing proper system voltage.

4. 4

   Inspect for a faulty connector at the ring speed sensor or a mechanical fault within the transmission.

1. 1

   Inspect Wiring and Connections

   Locate the ring speed sensor on the transmission. Disconnect the 2-pin connector and inspect the terminals for corrosion, pushed-back pins, or moisture.

2. 2

   Test the Sensor

   Since the code specifies that there is no short to 12V or ground, the issue is likely an open circuit inside the sensor, a critical air gap issue, or a completely failed sensor.

3. 3

   Replace the Sensor

   If the wiring harness tests good, remove the faulty ring speed sensor and install the replacement part.

4. 4

   Clear the Fault Code

   Once the repair is complete, you must clear the stored error codes. This can be done by accessing the controller menu (using the H8 or HC menu to erase stored error codes without erasing calibration information).

5. 5

   Test Operation

   Test the tractor's transmission system for normal operation to ensure the code does not return.