Case IH FCB – Transmission Control Module (TCU / Transmission Controller): Clutch B Not Calibrated

This code indicates that the transmission controller does not have valid calibration data for the Clutch B clutch pack. This typically happens if the transmission controller (processor) was recently replaced, if a memory clear (H8 mode) was performed, or if a previous calibration attempt failed due to a mechanical, hydraulic, or electrical issue.

• MXM
• MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Puma Series
• Puma 140
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Puma 225
• Puma 240
• Magnum Series
• Steiger Series

1. 1

   Determine if the TCU was recently replaced or if the memory was intentionally cleared (H8 mode), which naturally triggers this code.

2. 2

   Attempt a calibration and monitor for active 'U' (Calibration) codes that block the process (e.g., U19: oil temp below 10°C/20°C, U21/U22: engine RPM too low/high, U26: clutch pedal not released, U31: output speed sensed).

3. 3

   If calibration fails repeatedly on Clutch B, pressure test the Clutch B hydraulic circuit.

4. 4

   Inspect the Clutch B PWM solenoid valve for a faulty solenoid coil (short/open circuit), a clogged internal gauze filter, or a stuck mechanical spool.

1. 1

   Warm Up the Tractor

   Park the tractor in a wide-open, flat area away from obstacles. Engage the parking brake. Warm up the transmission fluid until the oil temperature is between 60°C and 105°C (140°F - 221°F). Calibration will fail if the oil is too cold.

2. 2

   Enter Calibration Mode

   Depending on the model, enter the transmission calibration menu (TCU -> TRANS SETUP -> Cltch Cal on AFS monitors, or via the H-Menu/diagnostic tool on older MXM models).

3. 3

   Calibrate the Clutches

   Follow the on-screen prompts to calibrate the clutches sequentially. When the display indicates that Clutch B is ready for calibration (usually displaying a lowercase 'b'), press and hold the designated calibration button. Keep holding the button as the engine RPM automatically adjusts (typically to around 1100 - 1300 RPM) and the controller gradually increases electrical current to the Clutch B PWM valve. Hold the button until the engine speed drops by exactly 50 RPM and the calibration number on the display stops increasing.

4. 4

   Address Calibration Failures

   If the calibration fails or errors out on Clutch B, remove the Clutch B PWM valve from the transmission valve block. Clean the valve and inspect the protective gauze filter for debris. Reinstall and retry calibration. If it still fails, replace the Clutch B PWM valve with a new unit. If a new valve does not fix the issue and the hydraulic circuit pressure is verified good, the transmission controller (processor) may be faulty and require replacement.

5. 5

   Save and Exit

   Once Clutch B (and the remaining clutches) calibrate successfully, the display will show 'CF' (Calibration Procedure Completed Successfully). Turn the key switch off to store the new calibration values in the TCU's memory.