Case IH 2025 (519407.13) - DEC – DEC (Driveline Electronic Controller): All synchros not calibrated

The transmission synchronizers have lost their stored calibration values, or a recent calibration attempt was unsuccessful. The transmission controller relies on precise stroke position data to engage the synchronizers smoothly. When this data is missing or out of tolerance (often due to battery replacement, voltage drops, or memory loss in the EEPROM), the controller cannot verify the synchronizer positions, resulting in a failure to shift or the tractor refusing to move. Repeated calibration failures may indicate physical damage to a synchronizer or a failed position sensor.

• MAXXUM T4E
• Magnum series
• Magnum 210
• MXM series
• MXM 120
• MXM 190
• Maxxum series
• MXU series
• MXU115
• Steiger series
• Puma series

1. 1

   Verify the health of the batteries and the charging system, as voltage loss can wipe the non-volatile memory (EEPROM)

2. 2

   Check the transmission oil level and condition, looking for milky (water-contaminated) or metallic-looking fluid indicating internal mechanical failure

3. 3

   Verify transmission oil is at operating temperature (ideally around 60°C) to ensure a successful calibration

4. 4

   Check for related codes like U19 or U89 (Low/High synchro calibration values out of tolerance), which point to mechanical wear rather than a software memory issue

1. 1

   Warm Up

   Operate the tractor until the transmission oil is thoroughly warmed up. Turn off the engine and ensure all electrical accessories (A/C, radio) are off.

2. 2

   Enter Calibration Mode

   Press and hold the upshift switch on the gear lever and start the engine. Within 3 seconds of starting, press the downshift switch to enter calibration mode. (The dash should display "CAL" or "H1").

3. 3

   Set Conditions

   Apply the park brake, place the range lever in neutral, move the shuttle lever to forward, and set the engine speed to exactly 1200 RPM.

4. 4

   Cycle to Synchro Calibration

   Press the upshift switch to cycle through the temperature display and the individual clutch packs (usually A through E).

5. 5

   Calibrate the Synchronizers

   When you reach the synchronizer calibration (often displayed as "F" or "CF"), press and hold the downshift switch. The display will show numbers ramping up as the controller checks the position of the synchronizer stroke and sets the values.

6. 6

   Save and Exit

   Hold the switch until the display alternates between the letter and the final calibration value. Once all synchros and clutches are calibrated, turn the engine off to store the new values in the controller's memory. Note: If calibration fails repeatedly or grinding/banging noises occur, a mechanical teardown is required.