Code 25201: Axis %1 drive fault
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical Axis %1 drive fault 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
Parameters: %1 = Axis name, spindle number Definitions: For PROFIdrive: The drive signals a serious fault which prevents the drive from being ready. The exact cause of the fault can be found by evaluating the additionally output drive alarms (It may be necessary to activate these diagnostic alarms by parameter izing the MDs DRIVE_FUNCTION_MASK, PROFIBUS_ALARM_ACCESS etc): Alarms 380500 and 380501 (or the corresponding alarm numbers implemented on the HMI side). The alarm can be reprogrammed in the MD11412 $MN_ALARM_REACTION_CHAN_NOREADY (channel not ready). Reaction: Mode group not ready. The NC switches to follow-up mode. Channel not ready. NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm. Channel not ready. Remedy: Evaluation of the drive alarms listed above. Program Continuation: Clear alarm with the RESET key in all channel s of this mode group. Restart part program.
Source: SINUMERIK 840D sl / 840Di sl / SINAMICS S120 Diagnostics Manual (DAsl, 03/2009)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Siemens SINUMERIK 840D CNC Alarms
Siemens controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code 25201 on the SINUMERIK 840D CNC identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Siemens's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 4014 Siemens SINUMERIK 840D CNC codes.
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