Code 346: Illegal M Code
Issue Description & Safety Warning
The Haas VF-Series CNC has triggered a critical Illegal M Code alarm. Immediate attention from a qualified operator or maintenance technician is required to prevent secondary damage to the equipment or spoiled parts during the manufacturing cycle. Always ensure standard safety and LOTO procedures are followed before accessing electrical cabinets.
Official Troubleshooting Steps
There was an M80 or M81 commanded. These commands are not allowed while Setting 51 DOOR HOLD OVERRIDE is OFF. Also check Setting 131 for Auto Door and Parameter 57 for DOOR STOP SP. B. There was an M17 or M18 commanded in program restart. These commands are illegal in program restart.
Source: Haas VF-Series Service Manual (96-8100 rev G, 2003)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Haas VF-Series CNC Alarms
Haas controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code 346 on the VF-Series CNC identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Haas's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 461 Haas VF-Series CNC codes.
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