: Cut away any corroded or broken wiring sections. Splicing should be done using heat-shrink waterproof connectors to prevent future moisture ingress.
: The internal elements of the thermistor crack or wear out over time, breaking continuity.
: Ensure that all connections are secure, and there are no obvious signs of damage or wear on components that could be related to the fault.
On older Doosan equipment (G2/G2+ stages), a NOx fault would manifest as generic SPN 3226 FMI 5 . On (Stage V / Tier 4 Final with Doosan DL06, DLO8, or Scania DC09/DC13 engines using Doosan’s proprietary CAN bus), VPV00105 includes self-healing logic :
An indicates an open coil that must be replaced. Step 3: Check Wiring Continuity and Voltage
Write down the exact code (e.g., VPV00105‑xx ). Also note:
Most overlooked: causing solenoid dither instability — the controller sees erratic feedback and logs VPV00105.
"Machine shows Doosan fault VPV00105 after VPV assembly replacement. Visual inspection OK, but diagnostic tool still reports VPV00105. Please check VPV wiring harness for continuity, test sensor supply/signal, verify system vacuum pressure spec, and confirm ECU firmware and relearn steps."
The Doosan fault code indicates that the Pump P1 (A) current is below normal
The sensor itself has internal electronics that fail due to vibration, heat cycles, or contamination. When the internal resistor fails open or shorted, the voltage signal spikes to 5V or drops to 0V.
When a "Current below normal" error surfaces, the issue is almost always electrical or electromagnetic, though it manifests as a hydraulic performance problem.
In very rare cases, severe mechanical damage inside the variable displacement pump (like a broken swashplate or stuck servo piston) causes pressure to exceed the sensor’s maximum rating (e.g., over 5,000 PSI). This creates a genuine voltage spike, but the root cause is mechanical, not electrical.
With the solenoid disconnected and the machine's ignition switched to the position (engine off):
Disclaimer: Heavy machinery repairs pose safety risks. Always consult your official Doosan/Develon operation and maintenance manual before performing electrical diagnostics. To help narrow down the specific repair steps, let me know:
Disconnect the plug at the P1 proportional valve and use a multimeter to measure the resistance of the solenoid coil. Compare this value to the manufacturer's specifications (usually a few ohms); an "O.L" (open loop) reading indicates a dead solenoid.
