CLAAS 769Dh – TR3: Rear PTO Brake Contact Short Circuit

The transmission control system has detected a short circuit to a 12-volt power supply in the electrical circuit responsible for signaling that the rear Power Take-Off (PTO) brake is inactive. The control module is receiving a constant 12V signal when it should not be, indicating a wiring issue or a failed component, which may affect the proper operation of the rear PTO brake system.

• Axion 810
• Axion 820
• Axion 830
• Axion 840
• Axion 850
• Arion 500 Series
• Arion 600 Series

1. 1

   Note all error codes present on the tractor, as one fault can sometimes trigger another

2. 2

   Check the connectors and ensure the continuity of the harnesses linking each component

3. 3

   Inspect for any short circuits or open circuits in the wiring

4. 4

   Verify the integrity of power sources, including fuses, and ground connections

5. 5

   Inspect the wiring harness connected to the rear PTO brake contact (S173) for damage, chafing, or corrosion that could cause a short to 12V

6. 6

   Test the rear PTO brake contact (S173) for proper operation and internal short circuits

7. 7

   Check the Auto 5 module using specialized diagnostic tool (Part No. 60 05 033 249)

1. 1

   Isolate the Fault

   Begin by performing the diagnostic checks listed above to determine if the fault lies within the wiring harness or the PTO brake contact itself.

2. 2

   Repair Wiring

   If a short circuit is found in the harness, repair the damaged section of the wire, ensuring a secure and insulated connection. If the damage is extensive, the harness section may need to be replaced.

3. 3

   Replace the Rear PTO Brake Contact (S173)

   If the contact is identified as the faulty component, it must be replaced.

4. 4

   Test the Auto 5 Module

   If the wiring and contact are found to be in good working order, the Auto 5 module should be tested by a qualified technician using the appropriate diagnostic tools. If found to be faulty, the module will require repair or replacement.

5. 5

   Clear Fault Codes

   After completing the repairs, clear all error codes from the system.

6. 6

   Verify the Repair

   Operate the tractor and the rear PTO to ensure that the fault code does not reappear and that the rear PTO brake functions correctly.