| Step | Check | Tool | Expected | |------|-------|------|----------| | 1 | Solenoid resistance (pump regulator) | Multimeter | 5–7 Ω | | 2 | PWM signal duty cycle at idle | Oscilloscope | 20–25% | | 3 | Voltage between solenoid low side and chassis ground | DMM | <0.2V | | 4 | Pump angle sensor feedback (if equipped) | Doosin Diagnostic Tool | 0.5–4.5V linear |
| Cause | Likelihood | Affected Models | |-------|------------|----------------| | Faulty main pump pressure sensor (P2 or P1) | High | DX225LC-5, DX300LC-5 | | Wiring harness chafing near the engine control box | High | DL550-5 wheel loader | | Intermittent short to +B in the VCU power supply | Medium | DX140LCR-5, DA30-5 ADT | | Corroded connector CN-129 (pump compartment) | Medium | All Tier 4 Doosan | | Failed VCU (rare, but growing in 2023–2025 models) | Low | DX380LC-7 | | Software glitch after Doosan’s “Mechatronics Update” | Medium | DX235LCR-5 | doosan fault code vpv00105 new
: Perform a continuity test on the wiring between the pump solenoid and the machine's main controller to rule out a broken wire. Reset the Code | Step | Check | Tool | Expected
