CLAAS Id7685h / 7685h (506) – TR3 (A57-3) Transmission Module: Overspeed in economy. The PTO is off.

The system detects an overspeed condition while operating in economy mode, even though the Power Take-Off (PTO) is disengaged. This is typically caused by a discrepancy in speed readings between the engine and the PTO, or a failure within the transmission control module.

• Axion 850
• Axion 810
• Axion 800
• Arion 650
• Arion 640
• Arion 620
• Arion 550
• Arion 530
• Arion 430
• Arion 420
• Arion 410

1. 1

   Rear PTO speed sensor (B142)

2. 2

   Engine speed sensor (B228-1) (located on the PTO clutch housing)

3. 3

   Actual engine speed (to verify if an overspeed condition is genuinely occurring)

4. 4

   The "Auto 5" module, which must be tested using CLAAS diagnostic tool n° 60 05 033 249

1. 1

   Note and Analyze

   Document the error code and check for any interacting codes that might have triggered this anomaly.

2. 2

   Harness & Connector Inspection

   Check the connectors and continuity of the harnesses linking the rear PTO speed sensor (B142) and the engine speed sensor (B228-1) to the TR3 module.

3. 3

   Circuit Testing

   Test the wiring for any short-circuits to ground/power or open circuits.

4. 4

   Component Testing

   Check the resistance and physical adjustment/gap of the inductive speed sensors (B142 and B228-1).

5. 5

   Power Supply Check

   Verify the sources of energy (fuses, supply voltage, and ground) to the sensors and the TR3 module.

6. 6

   Module Testing

   If the sensors and wiring are intact, use tool n° 60 05 033 249 to test the "Auto 5" electronic unit.

7. 7

   Replacement

   Replace the faulty sensor(s) or the Auto 5 module if it fails the diagnostic test.

8. 8

   Clear and Retest

   Clear all error codes from the memory, then test drive the tractor to ensure the anomaly does not reappear.