Case IH 2415 – Transmission Control Unit (CCU / UCM): Medium / reverse range synchronizer potentiometer - voltage too high.

The transmission controller is receiving a voltage signal from the medium/reverse synchronizer position sensor (potentiometer) that exceeds the maximum calibrated threshold. This typically points to a short to power in the sensor's signal wire, a loss of sensor ground, or an internal failure of the potentiometer itself.

• Optum
• Puma Series
• Magnum Series
• Steiger Series

1. 1

   Visually inspect the medium/reverse range synchronizer potentiometer connector and the CCU connector for damage, loose pins, or poor connections.

2. 2

   Check the 5-Volt reference circuit by measuring voltage between the 5V reference pin and chassis ground with the ignition ON (should be approx 5V).

3. 3

   Check the ground circuit for continuity or open circuit between the sensor's ground pin and chassis ground.

4. 4

   Check signal wire continuity between the potentiometer connector and the CCU connector with the ignition OFF.

5. 5

   Check for a short to power by measuring voltage between the signal wire and ground with the ignition ON.

1. 1

   Complete diagnostic wiring checks

   Complete the diagnostic wiring checks for the 5V reference, ground, and signal circuits.

2. 2

   Replace potentiometer

   If the wiring harness, 5V reference, and ground circuits test okay, the fault is internal to the sensor. Remove and replace the medium/reverse range synchronizer potentiometer.

3. 3

   Clear codes and calibrate

   Clear the fault codes and perform a transmission synchronizer/clutch calibration procedure as outlined in the operator's or service manual.

4. 4

   Update transmission software

   If the fault is still present after replacing the sensor and calibrating, connect the electronic service tool and download/flash the correct level of transmission software to the CCU.

5. 5

   Replace CCU

   If the fault recurs even after a software update, the CCU (Central Control Unit) is likely faulty and must be removed and replaced.