CLAAS Id7655h / 7655h (454) – TR2 (A57-2) Transmission Module: Calibration of the Power Boost ongoing.

This is a status or informational code indicating that the tractor's electronic system is currently in the middle of calibrating the Power Boost function. If this code remains active indefinitely or locks the operator out of normal functions, it means the calibration process has stalled, hung, or cannot complete due to a missing prerequisite signal (such as engine speed data).

• CLAAS Axion 850 / Axion 800 series
• CLAAS Arion 640–510 series
• CLAAS Arion 430–410 series

1. 1

   Check for concurrent Power Boost calibration fault codes (e.g., Id7640h or Id7641h) which indicate disconnected sensors.

2. 2

   Verify the adjustment, wiring continuity, and resistance of the engine speed sensors (B228-1 on the PTO clutch housing and B228-2 on the gearbox primary shaft).

3. 3

   Inspect the TR2 (A57-2) module harness and CAN bus network connections for short-circuits, open circuits, or pushed pins.

4. 4

   Check power and ground sources (fuses, supply voltage, and ground) to the TR2 transmission module.

1. 1

   Allow Calibration to Complete

   Ensure the tractor is in the proper operating state (correct temperature, parked safely) and allow the system time to finish the calibration.

2. 2

   Clear and Restart

   If the code is stuck, cycle the tractor's key power to reset the modules. Clear the fault codes using the CLAAS diagnostic interface.

3. 3

   Address Sensor Faults

   If engine speed sensors (B228-1 or B228-2) are found to be faulty or out of adjustment during your diagnostic checks, adjust their air gap or replace the faulty sensor.

4. 4

   Recalibrate

   Relaunch the Power Boost calibration procedure using the CLAAS "Auto 5" module and the official diagnostic tool (Tool n° 60 05 033 249).

5. 5

   Module Replacement

   If the wiring is intact, sensors are reading correctly, and the TR2 module refuses to complete calibration or communicate properly, the TR2 (A57-2) module itself may have an internal logic failure and will need to be replaced and reprogrammed.