CLAAS Id7698h / 7698h (525) – TR3 (A57-3) Transmission Control Module: Wear sensor of the automatic hand brake activated

The system has detected physical wear on the automatic hand brake components, or there is an electrical fault (such as a short circuit) falsely triggering the wear sensor.

• CLAAS Axion 800 series (e.g., 810, 840, 850)
• CLAAS Axion 900 series (e.g., 920, 950)
• CLAAS Arion 500 and 600 series (e.g., 510, 640)

1. 1

   Physically check the actual hand brake for wear

2. 2

   Check for a possible short-circuit on the sensor harness connected to component Z157

3. 3

   Check the automatic hand brake wear sensor itself (Component Z157)

4. 4

   Check the 'Auto 5' module using CLAAS diagnostic tool n° 60 05 033 249

1. 1

   Verify the Code

   Note the error codes present on the tractor's CEBIS terminal or diagnostic interface to confirm Id7698h is active.

2. 2

   Mechanical Inspection

   Access the automatic hand brake assembly and inspect the friction discs/pads for excessive wear. If the brake material is worn down to the sensor limit, replace the hand brake friction components.

3. 3

   Harness Inspection

   If the brake components are in good condition, trace the wiring harness from the Z157 wear sensor back to the TR3 module. Look for chafed wires, pinched harnesses, or exposed copper that could cause a short-circuit to ground or power. Repair any damaged wiring.

4. 4

   Sensor Testing

   Test the Z157 wear sensor for continuity and proper resistance. If the sensor is internally shorted or stuck in the "active" mode, replace the sensor.

5. 5

   Module Testing

   If the mechanical brake, wiring, and sensor all pass inspection, connect CLAAS diagnostic tool 60 05 033 249 to test the "Auto 5" module. Replace the module if it fails the diagnostic test.

6. 6

   Clear and Retest

   Clear all error codes from the TR3 module and test drive the tractor to ensure the anomaly does not reappear.