Case IH 520199-09 - VCM – UCM: Loss of communication between the steering valve controller and the steering wheel sensor

The steering wheel position sensor (often a SASA sensor) communicates its 360-degree rotational data to the controller via a CAN bus (J1939) network. This code triggers when the controller experiences a boot-up timeout or missing messages, meaning it is no longer receiving data from the sensor.

• MAGNUM AFS Connect
• Magnum AFS Connect Tractors (Models 180, 200, 220, 240, 250, 280, 310, 340, 380 with CVT or Full Power Shift)
• Vestrum CVX Series
• Optum Series
• Maxxum Series (with DCT or CVT transmissions)
• Axial-Flow Combines (e.g., 7010, 7120, 7230, 8010, 8120, 8230, 9010, 9120, 9230)

1. 1

   Verify the steering wheel sensor is receiving adequate power (9 to 32 VDC) and has a solid ground, as a lack of power causes a boot-up timeout.

2. 2

   Check the CAN bus wiring for physical damage, disconnected plugs, or invalid message sequences.

3. 3

   Ensure the Steering Valve Controller (SVC) and UCM are running the latest software (e.g., SVC software version 2.02).

1. 1

   Locate sensor

   Locate the steering wheel position sensor on the steering column.

2. 2

   Inspect connector

   Disconnect the sensor harness and inspect the connector pins for corrosion, moisture, or pushed-out pins.

3. 3

   Verify power and ground

   Using a multimeter, verify the presence of 9-32 VDC power and ground at the harness connector.

4. 4

   Test CAN wires

   Test the CAN High and CAN Low wires for continuity and ensure there are no shorts to ground or power between the sensor and the UCM.

5. 5

   Replace sensor if necessary

   If the wiring harness, power, and ground are all intact but the communication loss persists, the steering wheel sensor has failed internally and must be replaced.

6. 6

   Install and clear codes

   Install the new steering wheel sensor, reconnect the harness, and clear the fault codes.