Case IH 15323 - AST – AST (Auto Guidance / Steering): Steering valve controller - Too many errors

Triggered when the steering valve controller experiences an internal failure or software overflow where it registers more than 5 errors at the exact same time, forcing the steering system into a safe state.

• MAXXUM T4E
• VESTRUM CVX
• AFS Connect Magnum
• Farmall

1. 1

   Check for other active codes in the AST fault stack (e.g., Wheel Angle Sensor, SASA steering wheel sensor, or CAN communication faults) that may have triggered the stack overflow.

2. 2

   Check the PVED-CLS LED indicator flashing behavior to determine the current state of the main microcontroller.

3. 3

   Verify spool neutrality at boot-up to ensure the hydraulic spool inside the valve is within its programmed threshold.

4. 4

   Check power and ground to verify that the battery voltage to the steering valve controller is within the normal operating range.

1. 1

   Cycle Machine Power

   Turn the tractor off, wait for the modules to power down completely, and turn the key back on to reboot the PVED-CLS controller.

2. 2

   Address Underlying Faults

   If other codes are present (such as LVDT signal out of range, PWM calibration invalid, or CAN bus errors), diagnose and repair those specific circuits first.

3. 3

   Software Flash / Update

   Check if there is a software update available for the Steering Valve Controller (SVC) via the Case IH EST to resolve potential software interpolation overflow or underflow.

4. 4

   Replace the Controller/Valve

   If the code persists and no external wiring or sensor faults are found, the PVED-CLS controller has suffered an internal hardware/software failure and must be replaced.

5. 5

   Recalibrate the System

   If the PVED-CLS actuator or the entire OSPE steering valve is replaced, perform a manual spool calibration and recalibrate the Wheel Angle Sensor (WAS) and SASA steering wheel sensor using the service tool.