Case IH 520200-09 - VCM – UCM (Universal Control Module): Loss of communication between the steering valve controller and the vehicle speed sensor

The control module is no longer receiving the required vehicle speed data over the CAN bus network, which is critical for speed-sensitive steering adjustments and automated steering functions.

• MAGNUM AFS Connect
• Case IH Magnum AFS Connect tractors (Models 180, 200, 220, 240, 250, 280, 310, 340, 380, 400)
• Case IH Optum series tractors equipped with AFS Connect / UCM modules
• Case IH Steiger series tractors equipped with AFS Connect / UCM modules
• Case IH Puma series tractors equipped with AFS Connect / UCM modules
• Case IH Axial-Flow Combines (Midrange 5140/6140/7140 and 5150/6150/7150 series)

1. 1

   Check the wiring harness between the vehicle speed sensor and the UCM for physical damage, chafing, or corrosion at the connectors

2. 2

   Verify the physical installation of the vehicle speed sensor, checking the sensor gap and ensuring it is free of debris or metallic shavings

3. 3

   Test the CAN communication link to ensure the UCM is capable of receiving messages and check for CAN bus voltage errors

4. 4

   Check parameter settings in the diagnostic menu (e.g., tire size, gear ratio) to ensure correct configuration for speed calculation

5. 5

   Verify that the UCM is running the latest OEM software version (e.g., 15.2.0.0 or 1.17.0.0)

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical spikes during sensor handling.

2. 2

   Locate the Sensor

   Locate the vehicle speed sensor, typically mounted on the transmission housing, ranges box output, or rear differential.

3. 3

   Inspect and Clean

   Remove the sensor and inspect the tip for damage or heavy metallic buildup. Clean the mounting port.

4. 4

   Test Wiring Continuity

   Using a multimeter, pin out the harness from the speed sensor connector back to the UCM to verify continuity and ensure there is no short to ground or open circuit.

5. 5

   Replace Sensor (If Necessary)

   If the wiring is intact and the parameter settings are correct, the sensor itself has likely failed internally. Install a new vehicle speed sensor and torque it to OEM specifications, ensuring the correct sensor gap.

6. 6

   Clear Codes and Calibrate

   Reconnect the battery, clear the 520200-09 fault code via the diagnostic display, and perform a test drive to verify that the UCM is successfully receiving the speed signal.