Case IH 15322 – PVED-CLS Main and/or Safety Controller: Steering valve controller failure - LVDT signal B out of range

The LVDT (Linear Variable Differential Transformer) is an inductive transducer sensor that monitors the exact physical position of the electrohydraulic (EH) steering valve's main spool. When the controller flags "signal B out of range," it means the feedback signal (frequency, pulse width, or voltage) from the spool position sensor is outside the expected calibration parameters. Because the controller can no longer accurately verify the position of the steering spool, it will disable the electrohydraulic steering (AutoSteer/GPS guidance) and default to a "safe state" (manual hydraulic steering only) to prevent uncommanded steering movements.

• Steiger T4B
• Case IH Farmall Series (e.g., 40, 45, 50, 115U)
• Case IH Magnum Series (e.g., 220, 240, 250)
• Case IH Puma Series
• Case IH Steiger Series

1. 1

   Inspect the harness and connector at the PVED-CLS controller for moisture, corrosion, or pushed-out pins, which commonly cause out-of-range signal drops.

2. 2

   Using the Case IH EST or Danfoss PLUS+1 service tool, verify that the LVDT offset compensation is enabled (Parameter P3089 should be set to 255).

3. 3

   Check the hydraulic fluid for contamination and ensure the main spool moves freely to rule out mechanical binding preventing the spool from reaching the commanded position.

4. 4

   Verify sensor supply voltage and ground levels to the PVED-CLS are within normal limits (fluctuations below 9V can cause erratic sensor behavior).

1. 1

   Preparation

   Park the tractor on a solid, level surface. Turn off the engine, relieve all hydraulic pressure by turning the steering wheel back and forth, and remove the key.

2. 2

   Clean the Area

   Locate the OSPE/EHi steering valve assembly. Thoroughly clean the exterior of the valve and the PVED-CLS actuator to prevent any dirt from entering the hydraulic system during disassembly.

3. 3

   Removal

   Disconnect the electrical harness from the PVED-CLS controller. Remove the mounting screws that secure the PVED-CLS actuator module to the mechanical steering valve body.

4. 4

   Component Replacement

   If the LVDT sensor (which is integrated into the actuator interface) or the controller itself has failed, the PVED-CLS module must be replaced.

5. 5

   Installation

   Install the new PVED-CLS controller using a new seal kit to ensure a proper fluid-tight mate against the valve body. Torque the mounting screws to OEM specifications.

6. 6

   Calibration

   After replacing the PVED-CLS controller or the EHi steering valve, you must use the diagnostic service tool to calibrate the steering position sensor and the EH valve spool. A safety validation test must also be executed to unlock the controller from its initial boot-up safe state.

7. 7

   Testing

   Clear the fault codes, start the tractor, and test the AutoSteer functionality in an open area to ensure the LVDT tracks the spool position accurately.