Case IH 904-25 - VCM – VCM: Steering valve controller vehicle speed sensor disagreement

The steering valve controller is receiving a vehicle speed signal that conflicts with other speed data on the machine's network (such as radar, GPS, or wheel speed sensors).

• MAGNUM AFS Connect

1. 1

   Check for other active fault codes related to the CAN bus network, radar, or wheel speed sensors. Diagnose primary speed sensor or CAN communication faults first.

2. 2

   Check the CAN bus network for communication errors between the VCM, the steering valve controller, and the speed sensors.

3. 3

   Use a diagnostic tool to monitor the vehicle speed sensor signal in real-time and compare it against radar or GPS speed to identify the discrepancy.

4. 4

   Inspect the wiring harnesses and connectors for the vehicle speed sensor and the steering valve controller for shorts, open circuits, corrosion, or physical damage.

1. 1

   Read fault codes

   Connect the Case IH Electronic Service Tool (EST) to read all active and stored fault codes.

2. 2

   Inspect components and wiring

   Perform a visual and physical inspection of the vehicle speed sensor, the steering valve controller, and their respective wiring harnesses.

3. 3

   Repair wiring

   If wiring damage is found (e.g., a short to ground or open circuit), repair or replace the affected harness section.

4. 4

   Replace speed sensor

   If the wiring is intact but the speed sensor signal is erratic, missing, or out of range, replace the vehicle speed sensor.

5. 5

   Verify controller configuration

   If the sensor and wiring are functional, verify the configuration and software of the steering valve controller. An incorrect configuration can cause crosscheck failures.

6. 6

   Clear fault codes

   After replacing the faulty component or repairing the wiring, clear the fault codes using the diagnostic tool.

7. 7

   Test drive

   Cycle the ignition and perform a test drive to ensure the steering valve controller receives the correct vehicle speed signal and the fault code does not return.