Code 249152: <location>Cooling system: ON command feedback signal missing
Issue Description & Safety Warning
The Siemens SINUMERIK 840D CNC has triggered a critical <location>Cooling system: ON command feedback signal missing 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
Message value: Drive object: A_INF, B_INF, S_INF, SERVO, VECTOR Reaction: OFF2 Acknowledge: IMMEDIATELY Cause: The feedback signal of the ON command of the cooling syst em is missing. - after the ON command, the feedback signal has not been received within the selected starting time (p0260). - the feedback signal has failed in operation. See also: p0260 (Cooling system, starting time 1), r0267 (Cooling system status word) Remedy: - check the wiring between the cooling system and the input terminal (Terminal Module). - check the external control device for the cooling system.
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 249152 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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