Code T02-0205: Operation mode changed
Issue Description & Safety Warning
The Mitsubishi M800/M80 CNC has triggered a critical Operation mode changed 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
Details The operation mode has changed to an other mode during automatic operation. Remedy Return to the original automatic operation mode, and press the CYCLE START switch to resume the au- tomatic operation. Acc/dec time cnst too large 0206 Details The acceleration and deceleration time constants ar e too large. (This alarm occu rs with the system alarm Z59.) Remedy Set a larger value for "#1206 G1bF(Maximum speed)". Set a smaller value for "#1207 G1btL(Time constant)". Set a lower cutting speed. Abs posn detect alarm occurred 0215 Details An absolute position detection alarm occurred. Remedy Clear the absolute position detection alarm. Aux axis changeover error 0220 Details A travel command was issued to an auxiliary axis. Remedy Turn ON the "NC axis control selection" signal and press the CYCLE START switch to restart the auto- matic operation with. FEED HOLD: SOS axis 0221 Details SOS axis exists in the system. Remedy Cancel SOS state and execute cycle start, and you can continue automatic operation from the stop point. Single block stop signal ON 0301 Details The SINGLE BLOCK switch on the machine operation panel is ON. The SINGLE BLOCK or MACHINE LOCK switch changed. Remedy Press the CYCLE START switch to resume the automatic operation. Block stop cmnd in user macro 0302 Details A block stop command was issued in the user macro program. Remedy Press the CYCLE START switch to resume the automatic operation. Operation mode changed 0303 Details Automatic mode changed to another automatic mode. Remedy Return to the original automatic operation mode, and press the CYCLE START switch to resume the au- tomatic operation. MDI completed 0304 Details MDI operation has ended the last block. Remedy Set the MDI operation again, and press the CY CLE START switch to start the MDl operation.
Source: Mitsubishi M800/M80/E80 Series Alarm/Parameter Manual (IB-1501279)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Mitsubishi M800/M80 CNC Alarms
Mitsubishi controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code T02-0205 on the M800/M80 CNC identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Mitsubishi's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 722 Mitsubishi M800/M80 CNC codes.
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