CLAAS Id76B9h / 76B9h (736) – REH (A58): Voltage of the load control instruction signal non valid

The electronic signal coming from the load control dial/slider on the lifting control panel is outside of the expected voltage parameters (e.g., an open circuit, short to ground, or short to power). As a direct system response to this fault, the load control becomes inactive.

• CLAAS Axion 800 Series (810, 850)
• CLAAS Arion 400 Series (410, 430)
• CLAAS Arion 500/600 Series (510, 640)
• CLAAS Axos

1. 1

   Inspect the lifting control panel (Component V22) physical switches and potentiometers for the load control

2. 2

   Check the lifting module REH (Component A58) located under the right-hand console or behind the seat

3. 3

   Inspect the wiring harness and connectors between the V22 panel and the A58 module for water ingress, corrosion, chafed wires, or loose pins (Auto 5 modules are highly sensitive to moisture)

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the battery to prevent electrical spikes.

2. 2

   Locate Components

   Locate the V22 rear lifting control panel (in the cab armrest/console) and the REH (A58) Auto 5 module.

3. 3

   Harness Inspection

   Disconnect the harness at both the V22 panel and the A58 module. Inspect for green corrosion or moisture. Clean with contact cleaner if necessary.

4. 4

   Signal Verification

   Reconnect the battery and use a multimeter to back-probe the load control signal wire at the A58 module connector. Slowly sweep the load control dial on the V22 panel. The voltage should scale smoothly without dropping out or spiking.

5. 5

   Replace V22

   If the voltage drops out, is stuck at 0V, or is stuck at reference voltage (usually 5V or 12V), the potentiometer inside the V22 lifting control panel has failed and the panel must be replaced.

6. 6

   Replace/Repair A58

   If the V22 panel is outputting the correct, smooth voltage signal to the A58 module but the fault persists, the REH (A58) Auto 5 module has an internal failure.

7. 7

   Calibration

   If the A58 module is replaced, it must be programmed/calibrated to the tractor using the CLAAS Diagnostic System (CDS), as this generic module can be programmed for different functions (lift, transmission, front axle, etc.). Clear the fault codes and test the rear lifting system.