Fault Phenomenon: Volvo EC210 excavator after the control levers return to neutral, the engine does not enter auto-idle mode, always runs at high speed.

Troubleshooting Process:
– Checked sensor: pilot pressure sensor signal not at zero.
– Checked switch: auto-idle switch not engaged.
– Checked controller: ECU parameter setting error.
– Checked wiring: signal line interference.

Root Cause: The pilot pressure sensor has zero-point drift; even with levers in neutral, the ECU still detects a weak pressure signal, interpreting it as an operating state.

Required Parts: Calibrate or replace pilot pressure sensor.