CLAAS Id7699h / 7699h (526) – TR3 (A57-3): Automatic hand brake wear sensor blocked in active mode

The automatic hand brake wear information is no longer available to the system, likely due to the sensor being mechanically seized in the active position or an electrical fault mimicking this state.

• CLAAS Axion 800 Series
• CLAAS Axion 810
• CLAAS Axion 850
• CLAAS Axion 900 Series
• CLAAS Axion 920
• CLAAS Axion 950
• CLAAS Arion 500 / 600 Series
• CLAAS Arion 510-640

1. 1

   Check for a possible short-circuit on the sensor harness designated as Z157

2. 2

   Inspect the automatic hand brake wear sensor (Z157) for mechanical seizing or internal electrical failure

3. 3

   Test the "Auto 5" module using the specific CLAAS diagnostic tool (Part No. 60 05 033 249) to rule out a control unit failure

4. 4

   Verify the connectors and continuity of the harnesses linking the components. Check for open circuits, verify the component's resistance, and check the sources of energy (fuses, supply, and ground)

1. 1

   Locate Component Z157

   Find the automatic hand brake wear sensor (Z157) and its associated wiring harness on the transmission/brake assembly.

2. 2

   Inspect the Harness

   Disconnect the sensor and use a multimeter to test the Z157 harness for continuity, open circuits, or short-circuits to ground/power. Repair the wiring if damaged.

3. 3

   Inspect the Sensor

   Remove the Z157 sensor and check for physical blockages, dirt, or mechanical seizing that would cause it to be stuck in the "active" mode. Clean the mounting area. If the sensor is internally shorted or mechanically broken, it must be replaced.

4. 4

   Test the Auto 5 Module

   If the sensor and harness are in good working order, connect the CLAAS diagnostic tool (60 05 033 249) to test the Auto 5 module's inputs.

5. 5

   Replace and Clear

   Replace any faulty components (sensor, harness, or module), reconnect the system, and clear the fault codes from the TR3 (A57-3) module.