CLAAS Id75CEh / 75CEh (315) – TR1 (A57-1): Loss of theoretical speed information

The transmission control module is detecting a loss of the theoretical ground speed signal from the speed sensor while the tractor is in motion (indicated by the shuttle reverser output speed). The system notes that this specific fault is not detected when the operator is actively changing ranges or when a slow (crawler) range is engaged.

• Axion 800
• Axion 810
• Axion 850
• Axion 900
• Axion 960
• Arion 410
• Arion 430
• Arion 510
• Arion 530
• Arion 550
• Arion 610
• Arion 620
• Arion 630
• Arion 640
• Arion 650
• Nexos 230VL

1. 1

   Inspect the theoretical ground speed sensor (B227) for physical damage or heavy debris buildup.

2. 2

   Inspect the wiring harness connecting the B227 sensor to the TR1 (A57-1) transmission module and the DBD (A101) dashboard module. Look for disconnected plugs, corrosion, or broken wires.

3. 3

   Perform a resistance and frequency check on the B227 sensor using a multimeter to verify if the sensor is internally shorted or open.

4. 4

   Check the Powertrain CAN bus network for proper resistance, voltage, and continuity, as communication failures can trigger speed sensor faults.

5. 5

   Verify the connections at the TR1 (A57-1) transmission module and the A101 dashboard module.

1. 1

   Locate the Sensor

   Locate the B227 Theoretical Speed Sensor. Depending on the exact model, it is typically located on the rear axle crown or the transmission housing.

2. 2

   Clean the Area

   Clean the area around the sensor to prevent dirt from entering the transmission housing during removal.

3. 3

   Remove and Replace

   Disconnect the electrical connector. Unbolt and remove the faulty B227 sensor. Install the new sensor and torque to OEM specifications.

4. 4

   Reconnect and Clear Codes

   Reconnect the wiring harness. Turn on the battery master switch and clear the fault codes using the CLAAS Diagnostic System (CDS) or the onboard terminal.

5. 5

   Calibration

   If the error persists after replacement, calibrate the dashboard/transmission using the user manual procedures or the CLAAS Diagnostic System (CDS).

6. 6

   Test Drive

   Restart the tractor and carry out a test drive to ensure the theoretical speed registers correctly on the dashboard and the fault code does not return.