Case IH 15273 – Steering Valve Controller: Vehicle speed sensor crosscheck between the steering valve main and safety controllers failed

The primary and secondary speed values differ by more than 5.0 km/h (3.1 mph) for longer than 100 milliseconds, indicating a conflict. To prevent unpredictable or dangerous automated steering behavior, the controller immediately disables the off-road electrohydraulic steering mode (auto-steer) and defaults to the standard hydraulic on-road mode (manual steering).

• Steiger T4B
• Steiger
• Magnum
• Puma
• Optum

1. 1

   Connect the Electronic Service Tool (EST) and check for companion codes to see if a specific speed sensor has its own dedicated fault code active

2. 2

   Use the EST to monitor live data for the primary and secondary speed inputs to the steering controller while driving to identify which signal is dropping out, spiking, or reading zero

3. 3

   Inspect the wiring harnesses and connectors for both the transmission speed sensor and the radar/GPS speed sensor for rubbed wires, corrosion, or loose pins

4. 4

   Verify that the CAN bus communication between the transmission controller, the instrument cluster, and the steering valve controller is intact

1. 1

   Identify the Faulty Sensor

   Based on your EST live data test drive, determine whether the primary (transmission) or secondary (radar/GPS) speed signal is failing.

2. 2

   Test the Circuit

   Disconnect the faulty sensor and use a multimeter to check for proper reference voltage and ground at the sensor connector.

3. 3

   Repair Wiring

   If voltage or ground is missing, trace the harness back to the CCM/Transmission controller and repair any broken wires or corroded connectors.

4. 4

   Replace the Sensor

   If the circuit tests good but the sensor is outputting erratic or no data, replace the faulty speed sensor.

5. 5

   Calibrate and Clear

   After replacing the sensor, clear the fault codes using the EST.

6. 6

   Test Drive

   Perform a test drive to verify that the primary and secondary speed values now match. Once verified, engage the off-road electrohydraulic steering mode to ensure auto-steer functionality has been restored.