Code 14156: [Channel %1: ] Toolholder selection error at reset
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical [Channel %1: ] Toolholder selection error at reset 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 = Channel number Definitions: The settings in MD20110 $MC_RESET_MODE_MASK requir e that an active orientable toolholder is maintained after the reset. This is done by deselecti ng the old orientable toolholder and then reselecting it with data that may have been modified. If an er ror occurs during the reselection, this alarm is issued (as a warning) and then an attempt is made to select the orientable toolholder in the initial setting. If this second attempt is successful, the rese t cycle is continued wit hout any further alarms. Typically, the alarm only occurs when the old orientable toolholder has been selected with TCOFR, and its axis directions have been changed in such a way before the reset that a setting suitable for the associated frame is no longer possible. If there is anot her cause for the alarm, this results in an alarm also being issued when attempting to select in the init ial setting. This is then also displayed in plain text. Reaction: Alarm display. Remedy: Check the program. Program Continuation: Clear alarm with NC ST ART or RESET key and continue the 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 14156 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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