Case IH 55027: Voltage is not detected on the 'Front PVE-Power' driver pin when expected

The controller is commanding the digital output pin to supply power (battery voltage) to the front PVE actuator, but the controller's internal monitoring circuit is not detecting the expected voltage on that driver pin. This typically means there is an open circuit, a short-to-ground that has caused the controller's over-current protection to latch the output off, or a failure within the controller's output driver.

• STX Steiger

1. 1

   Check for Over-Current Latch: Cycle the power or reset the hydraulic command to see if the voltage returns, as the controller may have latched the output off due to a short.

2. 2

   Inspect the Wiring Harness: Check the wiring between the controller's output pin and the Front PVE power pin. Look for chafed wires causing a short to ground.

3. 3

   Test the Connector: Disconnect the harness at the Front PVE. Command the function and measure the voltage at the power pin on the machine harness side to see if voltage is present when the actuator is removed from the circuit.

4. 4

   Check the PVE Actuator: If voltage is present when the PVE is unplugged but drops out (or latches off) when plugged in, the PVE actuator may have an internal short.

1. 1

   Power Down

   Turn off the machine and disconnect battery power before servicing the hydraulic electrical connections.

2. 2

   Repair Wiring

   If the diagnostic checks reveal an open circuit or a short to ground in the harness, repair the damaged section of the wire or replace the affected harness segment.

3. 3

   Clean/Replace Connectors

   If the connector pins at the PVE or the controller are corroded (causing an open circuit), clean the pins with contact cleaner and apply dielectric grease, or replace the connector pigtail.

4. 4

   Replace the PVE Actuator

   If the wiring is intact but the PVE actuator is internally shorted (causing the controller to cut power to the pin), unbolt the faulty PVE module from the PVG valve block and install a new one.

5. 5

   Clear Codes and Test

   Reconnect the battery, cycle the key, clear the fault codes, and operate the front hydraulic function to verify the voltage is now detected and the valve operates smoothly.