CLAAS Id769Dh / 769Dh (530) – TR3 (A57-3): Short-circuit at the 12V of the rear PTO brake contact

Short-circuit at the 12V of the rear PTO brake contact, causing the rear PTO brake to become inactive.

• CLAAS Axion 850 - 810 series
• CLAAS Axion 950 - 920 series
• CLAAS Arion 640 - 510 series

1. 1

   Inspect the rear PTO brake contact (S173) for physical damage or internal failure.

2. 2

   Check the wiring harness connecting to the S173 contact for a short-circuit to 12V, and verify connectors and continuity.

3. 3

   Perform general electrical checks including component resistance, fuses, power supply, ground, and look for open circuits.

4. 4

   Test the 'Auto 5' module using the official CLAAS diagnostic tool (Tool n° 60 05 033 249).

1. 1

   Power down machine

   Disconnect the battery or ensure the machine is powered down safely before inspecting the electrical system.

2. 2

   Locate contact

   Locate the rear PTO brake contact (designated as S173 in the wiring diagram).

3. 3

   Test and repair wiring harness

   Disconnect the harness at the S173 contact and use a multimeter to test the wiring harness for a short-circuit to 12V power. Repair or replace the wiring harness if a short is found.

4. 4

   Test and replace contact

   Test the S173 contact itself for proper resistance and operation. If the contact is internally shorted, replace it.

5. 5

   Test module

   If the wiring and the contact test fine, connect the CLAAS diagnostic tool (n° 60 05 033 249) to test the 'Auto 5' module.

6. 6

   Replace module

   If the diagnostic tool indicates a failure in the module, replace the 'Auto 5' module.

7. 7

   Clear codes and verify

   Clear the fault codes from the TR3 module memory and test the rear PTO brake operation to verify the repair.