CLAAS Id77EDh / 77EDh (31) – HYD (A60) - Hydraulic Module: Power supply of valve 4 is too low (less than 8 V)

The system is detecting an insufficient voltage level (less than 8 V) reaching the electrodistributor module for the 4th hydraulic spool valve, which will prevent the valve from operating correctly.

• Axion 800
• Axion 810
• Axion 820
• Axion 830
• Axion 840
• Axion 850

1. 1

   Measure the power supply voltage directly at the connector for the electrodistributor module (A105-4) to confirm if it is receiving less than 8V.

2. 2

   Check the connectors and the continuity of the wiring harnesses linking the HYD (A60) module to the A105-4 electrodistributor module.

3. 3

   Inspect the wiring for any short-circuits to ground or open circuits.

4. 4

   Check the sources of energy, including the relevant fuses, main power supply relays, and ground connections.

5. 5

   Check the internal resistance of the electrodistributor module to ensure it hasn't failed internally and pulled the reference voltage down.

1. 1

   Document Codes

   Note all error codes present on the tractor, as an underlying power supply issue might generate multiple codes across different modules.

2. 2

   Inspect Wiring

   Visually inspect the wiring harness leading to hydraulic valve 4 (A105-4) at the rear hydraulic block. Look for chafed wires, pinched harnesses, or corrosion inside the connector pins.

3. 3

   Test and Repair Circuit

   If the voltage at the valve is below 8V, trace the circuit back to the HYD (A60) module and the fuse panel. Repair any damaged wires, clean corroded grounds, or replace blown/corroded fuses.

4. 4

   Replace Component

   If the wiring, grounds, and fuses are all in perfect condition and supplying the correct voltage, but the code remains active, the electrodistributor module (A105-4) itself has likely suffered an internal electrical failure and must be replaced.

5. 5

   Clear and Retest

   Clear all error codes from the system using the diagnostic interface. Operate the tractor and actuate hydraulic valve 4 to ensure the anomaly does not reappear.