CLAAS Id7839h / 7839h – MFA (A100) or HYD (A60): Auto pilot contact voltage too low / Broken communication with Valve 1

When logged by the MFA (A100) module, the voltage of the signal specified by the Auto pilot contact is too low, causing the Autopilot to become inactive. When logged by the HYD (A60) module, there is broken communication with Valve 1, causing the sequence to stop.

• CLAAS Axion 800
• CLAAS Axion 810
• CLAAS Axion 850
• CLAAS Axion 920
• CLAAS Axion 950
• CLAAS Arion 510
• CLAAS Arion 640

1. 1

   If MFA (A100) related: Check the Auto pilot contact (switch/button) for physical damage or sticking.

2. 2

   If MFA (A100) related: Check the MFA (A100) armrest multifunction module.

3. 3

   If MFA (A100) related: Check the sources of energy (fuses, supply, and ground) to the armrest.

4. 4

   If HYD (A60) related: Check the HYD (A60) module.

5. 5

   If HYD (A60) related: Inspect the electrical wiring and connectors between the HYD module and Valve 1 for open circuits or short-circuits.

6. 6

   If HYD (A60) related: Check the physical Valve 1.

7. 7

   If HYD (A60) related: Check the external function module EXT (A62).

1. 1

   Identify the Source

   Use the CEBIS terminal or a CLAAS diagnostic tool to determine whether the MFA (A100) or HYD (A60) module is throwing the Id7839h code.

2. 2

   Test and trace wiring for MFA (A100)

   For MFA (A100) Autopilot Issues: Test the voltage at the Autopilot contact switch. Trace the wiring harness from the switch to the MFA (A100) module. Repair any broken wires or corroded pins causing the 'voltage too low' condition.

3. 3

   Replace or recalibrate MFA (A100)

   For MFA (A100) Autopilot Issues: If the wiring is intact and the switch tests good, the MFA (A100) module itself may be faulty and require replacement or software recalibration.

4. 4

   Inspect wiring for HYD (A60)

   For HYD (A60) Valve 1 Issues: Inspect the wiring harness connecting the HYD (A60) module to Valve 1. Repair any broken communication lines.

5. 5

   Test and replace Valve 1

   For HYD (A60) Valve 1 Issues: Test Valve 1 for proper resistance. Replace the electrodistributor valve if it has failed internally.

6. 6

   Verify EXT (A62) and reset CSM

   For HYD (A60) Valve 1 Issues: Verify communication with the EXT (A62) module. Reset the CLAAS Sequence Management (CSM) and relaunch the sequence.

7. 7

   Clear Codes

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