Case IH 15266 – Steering Valve Controller (SVC): Steering valve controller failure - Overvoltage supervisor synchronization between main and safety controllers failed

The main and safety controllers within the Steering Valve Controller (PVED-CLS) failed to synchronize their readings regarding the overvoltage supervisor's state. This is a critical safety fault that forces the steering system into a safe state, disabling auto-guidance and reverting the tractor to manual hydraulic steering.

• Steiger T4B
• Case IH AFS Connect Magnum Tractors (Models 180, 200, 220, 240, 250, 280, 310, 340, 380)
• Case IH Vestrum CVX Series Tractors (Models 100, 110, 120, 130)
• Case IH Optum Series Tractors (Models 250, 270, 300)
• Case IH Steiger / Quadtrac models equipped with AFS Connect and PVED-CLS steering

1. 1

   Verify the tractor's charging system is outputting a stable voltage without excessive AC ripple, as severe voltage spikes from a failing alternator voltage regulator can trigger overvoltage supervisor faults.

2. 2

   Inspect the wiring harness and connectors leading to the Steering Valve Controller on the steering block for chafed wires, water intrusion, or loose pins that could cause intermittent shorts to power.

3. 3

   Perform a power and ground drop test directly at the SVC connector under load to ensure stable power delivery.

4. 4

   Clear the fault code and cycle the ignition. If the code returns immediately upon power-up or during the controller's initialization self-test, it indicates a hard internal hardware failure of the PVED-CLS controller.

1. 1

   Preparation

   Disconnect the tractor's battery to prevent electrical shorts or accidental hydraulic actuation.

2. 2

   Removal

   Locate the Steering Valve Controller (PVED-CLS) mounted on the electrohydraulic steering valve block. Disconnect the CAN bus and power harnesses from the controller. Unbolt and remove the faulty controller module from the valve block.

3. 3

   Installation

   Install the new PVED-CLS controller onto the valve block and torque the mounting bolts to OEM specifications. Reconnect the electrical harnesses and the battery.

4. 4

   Hydraulic Bleeding

   Before operating, all air must be bled from the steering system. Turn the steering wheel fully left, then fully right, a minimum of 10 times. Ensure no abnormal noise or vibration occurs during manual steering.

5. 5

   Software Flashing

   Connect the Case IH Electronic Service Tool (EST). The new controller will be blank and must be flashed with the correct machine-specific software and advanced steering configuration datasets.

6. 6

   Calibration

   Perform the steering calibration routine. Danfoss and Case IH mandate that this calibration must be performed on an on-road surface (i.e., unpainted concrete or asphalt) to ensure proper tire friction for the wheel angle sensors.