CLAAS Id780Fh / 780Fh – HYD (A60) - Hydraulic Module: Voltage of the signal from the front external lifting controls is too low

The voltage of the signal from the front external lifting controls is too low, pointing to a fault with the signal coming from the front lifting external control (up) switch (U59-1). As a safety and operational measure, the front external lifting controls are rendered inactive.

• Axion 810
• Axion 820
• Axion 830
• Axion 840
• Axion 850
• Axion 920
• Axion 930
• Axion 940
• Axion 950
• Arion 410
• Arion 420
• Arion 430
• Arion 500 series
• Arion 600 series

1. 1

   Check the connectors and the continuity of the wiring harnesses linking the front lifting external control (up) switch (U59-1) to the HYD (A60) module

2. 2

   Check the wiring for any short-circuits to ground or open circuits

3. 3

   Check the sources of energy, including fuses, power supply voltage, and ground connections at the switch

4. 4

   Check the resistance of the U59-1 switch itself to see if it has failed internally

5. 5

   Check for mechanical seizing or physical damage to the external switch housing on the front linkage

1. 1

   Verify the Fault

   Note the error codes present on the tractor and confirm the symptom (front external lifting controls are inactive).

2. 2

   Access the Switch

   Locate the front lifting external control (up) switch (U59-1) mounted on the front linkage/grille area.

3. 3

   Inspect Wiring

   Disconnect the switch and inspect the connector pins for corrosion, moisture ingress, or damage.

4. 4

   Test the Circuit

   Using a multimeter, verify that the switch is receiving the correct reference voltage and ground. Test the signal wire back to the HYD (A60) module for continuity.

5. 5

   Replace if Faulty

   If the wiring is intact, power/ground is present, but the switch fails a resistance/continuity test when pressed, the switch is defective and must be replaced.

6. 6

   Clear and Retest

   After replacing the switch or repairing the harness, clear all error codes from the system. Test the front linkage using the external controls to ensure the anomaly does not reappear.