Case IH 2500 – UCM: Transmission Input overspeed error

This code indicates that the transmission input speed sensor is detecting a rotational velocity (RPM) that exceeds the maximum allowable threshold programmed into the control unit.

• Optum
• Steiger T4B
• Case IH Puma 115
• Case IH Puma 125
• Case IH Puma 140
• Case IH Puma 150
• Case IH Puma 165
• Case IH Puma 185
• Case IH Puma 200
• Case IH Puma 220
• Case IH Puma 240
• Case IH Magnum series
• Case IH Maxxum series

1. 1

   Check if an external power supply (such as a battery charger or jump box) is currently connected to the tractor's battery.

2. 2

   Test the tractor's alternator and charging system for an overvoltage condition.

3. 3

   Inspect the wiring harness and the connector at the transmission input speed sensor for chafing, corrosion, or a short circuit.

4. 4

   Verify the Central Control Unit (CCU) or Universal Control Module (UCM) if the sensor, wiring, and charging system are functioning correctly.

1. 1

   Clear and Retest

   If an external power supply was connected, remove it, clear the error code from the UCM via the dashboard diagnostic menu, and test the tractor to see if the code returns.

2. 2

   Test Voltage

   Use a multimeter to verify that the battery voltage does not spike abnormally while the engine is running. Repair the alternator if overcharging is detected.

3. 3

   Inspect the Sensor

   Locate the transmission input speed sensor (typically positioned on the main transmission housing or gear monitoring blocks). Disconnect the plug and check for internal sealing leaks, oil intrusion, or damaged pins.

4. 4

   Replace the Sensor

   If the wiring is intact and the charging system is normal, the magnetic inductive speed sensor has likely failed. Remove the retaining bolt, pull the old sensor from the housing, and install a new OEM sensor.

5. 5

   Final Calibration

   Clear the fault code and test the system for normal operation. Depending on the transmission type (e.g., CVT or AutoCommand), a clutch or transmission calibration may need to be performed after replacing speed sensors.