Case IH 520202-02 - VCM – VCM: Communication failure with steering valve controller

This fault indicates a communication failure between the machine's main control module and the steering valve controller regarding an auxiliary steering device. The FMI 02 designation specifically means that the data being transmitted over the network is erratic, intermittent, or incorrect.

• MAGNUM AFS Connect
• Magnum series (180-340 models)
• Farmall series

1. 1

   Perform safety prep: place machine on a flat surface, chock wheels, turn off engine, remove key, and relieve all hydraulic pressure

2. 2

   Verify the 12V/24V DC power supply at the steering valve controller terminals is stable (drops below 5.5V cause communication dropouts)

3. 3

   Check software configuration to ensure only one auxiliary steering device is mapped per steering system and the checksum is correct

4. 4

   Inspect the J1939 CAN bus communication lines between the VCM and the steering valve controller for continuity, short circuits, or excessive bandwidth usage

1. 1

   Secure the Machine

   Follow the safety and hydraulic pressure relief procedures outlined above.

2. 2

   Inspect Wiring and Harnesses

   Disconnect the harness at the VCM and the steering valve controller. Inspect the pins for corrosion, moisture, or push-back.

3. 3

   Test the CAN Network

   Use a multimeter to check the resistance across the CAN High and CAN Low pins to ensure the terminating resistors are intact and the wiring is not shorted to ground or power.

4. 4

   Software/Calibration

   Connect a compatible diagnostic tool (such as the Case IH Electronic Service Tool or Jaltest) to the machine's diagnostic port. Read the live data for the steering valve controller's input pins.

5. 5

   Reconfigure the Controller

   If the controller lost its parameters, re-enter the calibration service mode and ensure the valve type is correctly set to OSPE/EHi-E or EHi-H, and that the auxiliary device is properly mapped.

6. 6

   Clear Codes

   Once the physical wiring is repaired or the module is reconfigured, use the diagnostic software to clear the fault codes from the VCM.