Case IH 15319 – Steering Valve Controller: Steering valve controller failure - Vref signal out of range

The reference voltage (Vref) generated by the steering valve controller is outside of its expected operating parameters (typically 5 volts). This usually points to a short circuit in the sensor wiring, a failed sensor pulling the voltage down, or an internal hardware failure within the controller's voltage regulator.

• Steiger T4B
• Case IH Steiger & Quadtrac series (e.g., 350, 370, 500, 550, 580, 600, 620)
• Case IH Magnum and MX Magnum series
• Case IH Puma and Optum series

1. 1

   Inspect the wiring harness connecting the PVED-CLS steering valve controller to the steering sensors (LVDT, Wheel Angle Sensor) for chafing, corrosion, or pinched wires.

2. 2

   Disconnect the sensors powered by the steering controller one at a time. If the Vref voltage returns to normal, the disconnected sensor is internally shorted.

3. 3

   Verify that the main battery voltage supplying the PVED-CLS controller is within the normal operating range to rule out voltage spikes or drops.

4. 4

   Test the controller by checking if the Vref signal remains out of range at the controller pins while the wiring harness is intact and all sensors are unplugged.

1. 1

   Power Down

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

2. 2

   Repair Wiring/Sensors

   If the diagnostic checks revealed a shorted wire or a faulty sensor (like the Wheel Angle Sensor), repair the harness or replace the sensor.

3. 3

   Replace the Controller

   If internally failed, locate the EHi steering valve assembly. Remove the mounting screws securing the PVED-CLS module to the hydraulic valve block.

4. 4

   Install New Module

   Install the replacement PVED-CLS module. It is highly recommended to replace the port seals between the module and the valve block during this process.

5. 5

   Calibrate the System

   Using the Case IH Electronic Service Tool (EST) or Autopilot Toolbox, navigate to the 'Setup and Diagnostics' interface, select 'Auto Steering Calibration Mode', and perform the automated steering calibration.