Code 274: C Limit Switch
Issue Description & Safety Warning
The Haas VF-Series CNC has triggered a critical C Limit Switch 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
Axis hit limit switch or switch disconnected. The stored stroke limits should stop the slides before they hit the limit switches. Verify the value of parameter Grid Offset and check the wiring to the limit switch and connector P5 at the side of the main cabinet. Can also be caused by a loose encoder shaft at the back of the motor or coupling of motor to the screw.
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 274 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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