Mitsubishi Electric Error 404

Brand: Mitsubishi ElectricModel: PLC (FX5U / iQ-R / iQ-F Series)Error code: Error 404

What the Fault Means

CPU communication timeout

Likely causes

  • Ethernet or serial connection to PLC lost; wrong PLC model selected in GT Designer3

Solution and Safe First Checks

  1. Verify connection settings; check cable; select correct PLC model (MELSEC iQ-R/FX5U etc.)

Safety: do not work inside the panel without isolating the power; if unsure, consult a qualified technician.

Related Mitsubishi Electric error codes

Source: the Zeror.ai industrial fault database and Mitsubishi Electric technical documentation. This page is for information; on critical systems follow the manufacturer's manual and authorised service.

Mitsubishi Electric Error 404 · Zeror.ai