CLAAS Id768Bh / 768Bh (512) – Transmission Control Module (TR3): Regulation of the PTO’s progressivity is not operating optimally.

The system detects that the Power Take-Off (PTO) engagement or speed regulation is not matching the expected parameters. As a result, the PTO continues running in poor or degraded conditions.

• Axion 810
• Axion 850
• Axion 920
• Axion 950
• Axion 960
• Arion 400 series
• Arion 410
• Arion 420
• Arion 430
• Arion 500 series
• Arion 510
• Arion 600 series
• Arion 640

1. 1

   Check the rear PTO speed sensor (B142): Verify the sensor's physical condition, mounting, and harness connections.

2. 2

   Check the engine speed data: Ensure the engine speed sensor (B228-1, located on the PTO clutch housing) is providing accurate data to the system.

3. 3

   Check the Powertrain CAN bus network: Inspect for communication errors, short circuits, or open circuits on the CAN-High (approx. 2.7V) and CAN-Low (approx. 2.3V) lines.

4. 4

   Check the "Auto 5" module: Test the electronic module using the specific CLAAS diagnostic breakout tool (n° 60 05 033 249).

1. 1

   Visual & Harness Inspection

   Start at the rear PTO speed sensor (B142). Inspect the wiring harness for chafing, breaks, or corrosion at the connector.

2. 2

   Sensor Testing

   Test the B142 PTO speed sensor and the B228-1 engine speed sensor for proper resistance and signal output. If the sensor is dead or providing erratic Hz readings under load, replace it.

3. 3

   CAN Bus Verification

   Using a multimeter or oscilloscope, probe the Powertrain CAN bus at the TR3 module connector to ensure network integrity. Look for a standard 60-ohm resistance across the CAN lines with the battery disconnected.

4. 4

   Module Diagnostics

   If the sensors and wiring are intact, connect the CLAAS diagnostic tool (60 05 033 249) to the "Auto 5" module to run a component test.

5. 5

   Replacement & Calibration

   If the Auto 5 module fails the test, replace it. After replacing the module or sensors, clear the fault codes using the METADIAG / CLAAS Diagnostic System (CDS) and perform a PTO progressivity adjustment/calibration.