Case IH 520248-25 - VCM – UCM (Universal Control Module): Steering valve controller auxiliary device signal disagreement

This code indicates a severe signal cross-check failure involving the auxiliary steering device (the steering joystick). The steering controller detects that the transmit rate of the primary and redundant signals from the joystick deviate too much from each other, or that the controller's parameter settings (specifically parameter P3387) do not match the installed auxiliary joystick.

• MAGNUM AFS Connect
• Magnum AFS Connect series
• Magnum 400 AFS Connect
• Steiger series
• 621E Wheel Loader
• 821F Wheel Loader
• 1021F Wheel Loader
• 1121F Wheel Loader

1. 1

   Verify steering controller parameters (specifically P3387) using the Case IH Electronic Service Tool (EST) to ensure they match the installed auxiliary joystick.

2. 2

   Monitor the primary and redundant enable signals from the auxiliary steering joystick for transmit rate deviations or intermittent dropouts.

3. 3

   Visually inspect the wiring harness and connectors between the steering joystick and the UCM/steering valve controller for pinched wires, loose pins, or corrosion.

1. 1

   Connect Diagnostic Tool

   Hook up the Case IH EST to the machine's diagnostic port.

2. 2

   Check Configurations

   Navigate to the UCM/Steering Valve Controller settings. Ensure the software configuration matches the physical joystick hardware. If the configuration is incorrect or corrupted, re-flash or reconfigure the controller parameters to match the installed auxiliary device.

3. 3

   Test Wiring

   Disconnect the harness at the joystick and at the steering valve controller. Perform a continuity and short-to-ground test on the signal wires. Repair or replace the joystick steering harness if resistance is out of spec or a short is found.

4. 4

   Replace Faulty Component

   If the wiring is intact and the parameters are correct, the fault lies within the internal sensors of the auxiliary steering joystick or the Danfoss PVED-CLS steering valve controller itself. Replace the faulty joystick assembly.

5. 5

   Calibrate and Clear

   After replacing the joystick or repairing the harness, clear the stored fault codes. Perform a steering system calibration/cross-check test to ensure the primary and redundant signals are now in agreement and the code does not return.