CLAAS Id7815h / 7815h – HYD (A60): Voltage of the signal from the external controls of the rear hydraulic distributor is too low

The voltage of the signal from the external controls of the rear hydraulic distributor is too low. As a safety and operational measure, the rear external controls of the hydraulic distributor are rendered inactive.

• CLAAS Axion 800 Series
• CLAAS Axion 810
• CLAAS Axion 830
• CLAAS Axion 840
• CLAAS Axion 850
• CLAAS Axion 900 Series
• CLAAS Axion 920
• CLAAS Axion 950
• CLAAS Arion 600 Series
• CLAAS Arion 500 Series
• CLAAS Arion 400 Series
• CLAAS Arion 640-510

1. 1

   Inspect the rear right contact of the electrodistributor (Component U55-2), which is the external hydraulic control switch on the lower right rear fender

2. 2

   Check the connectors and the continuity of the wiring harness linking the U55-2 switch to the HYD (A60) module

3. 3

   Test the circuit for any short-circuits to ground or open circuits that would cause a low voltage reading

4. 4

   Check the sources of energy (fuses, 12V supply, and ground) to the switch

5. 5

   Verify the condition and connections of the HYD (A60) hydraulic module itself

1. 1

   Locate the Switch

   Find the external hydraulic command switch (Component U55-2) on the right rear fender.

2. 2

   Inspect for Damage

   Visually inspect the switch, its rubber boot, and the wiring pigtail for physical damage, moisture ingress, or corrosion (common on fender-mounted components).

3. 3

   Test the Circuit

   Disconnect the U55-2 switch. Using a multimeter, check the reference voltage coming from the HYD (A60) module to the switch connector.

4. 4

   Test the Switch

   Measure the resistance of the U55-2 switch while pressing the button to ensure it opens and closes the circuit properly.

5. 5

   Repair Wiring or Replace Switch

   If the wiring harness has rubbed through and shorted to the chassis (causing the low voltage), repair the broken wire. If the switch fails the resistance test or is internally shorted/corroded, replace the U55-2 switch.

6. 6

   Clear Codes

   Reconnect the system, turn the ignition on, and clear the fault codes. Test the rear fender hydraulic controls to ensure they are active again.