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FANUC Alarm Code Guide

Find solutions to common Fanuc CNC alarm codes quickly and efficiently.

Servo Alarm
Spindle Alarm
System Alarm
Overtravel Alarm

FANUC Alarms: Quick Guide to Get Back Online​

When your FANUC CNC triggers an alarm, it's trying to tell you something. From simple overtravel to complex servo issues, these codes pinpoint where the problem lies.Our guide cuts through the complexity. We explain the most common alarms—what they mean, why they happen, and how to fix them. Whether you're facing alarm 401 or a stuck overtravel limit, you'll find clear, step-by-step solutions to minimize downtime.​​ You will learn how to:​​

  • Decode any FANUC alarm number.
  • Diagnose faults in servos, spindles, or system memory.
  • Perform basic checks before calling a technician.
  • Identify components that may need adjustment or replacement.

Get the knowledge to solve problems faster and keep your machines running.
FANUC SV Alarm Codes: FSSB, Axis Configuration and Servo Setup Errors
This page covers FANUC SV alarms related to FSSB communication, servo initialization, axis assignment, tandem drive settings, configuration mismatches, and servo setup errors. These alarms are especially important during machine commissioning, control replacement, amplifier replacement, parameter restoration, software changes, and troubleshooting after wiring or configuration work. These alarm references apply to FANUC Series 0i-Model D and FANUC Series 0i Mate-Model D. In practical maintenance work, these alarms often indicate that the CNC, amplifier, axis card, servo software, or axis allocation settings are not aligned correctly. Unlike pure overheat or current... Read more...
FANUC SV Alarm Codes: Servo Amplifier, Drive, Voltage and Overheat Alarms
This page covers FANUC SV alarms related to servo amplifiers, drive circuits, current detection, voltage status, DC link conditions, cooling fan faults, detector disconnection, FSSB communication, and servo hardware configuration. These alarms are especially important in maintenance and repair work because they are often associated with amplifier health, power conditions, wiring integrity, cooling performance, and system-level servo communication. These alarm references apply to FANUC Series 0i-Model D and FANUC Series 0i Mate-Model D. For service engineers, maintenance teams, and machine owners, this group of SV alarms is one of the... Read more...
FANUC SV Alarm Codes: Synchronization, APC and Encoder Alarms
This page covers FANUC SV alarms related to synchronization control, APC communication, built-in pulse coders, and external detectors. These alarms are commonly associated with position feedback, absolute position detection, encoder communication, detector data errors, and synchronization performance between axes. For maintenance engineers and machine tool service teams, this group of SV alarms is important because it often points to feedback problems, detector cable issues, APC communication faults, or synchronization deviations that affect machine motion accuracy. These alarm references apply to FANUC Series 0i-Model D and FANUC Series 0i Mate-Model D.... Read more...
FANUC SW Alarm List: SW0100 Parameter Write Enable Alarm
The FANUC SW alarm category is related to parameter write status. In most cases, this alarm appears when parameter writing has been enabled on the CNC. The most common code in this category is SW0100, which indicates that the Parameter Write Enable setting is turned on. This page explains what SW0100 means, when it may appear, and what users should check before changing parameters on a FANUC CNC system. For maintenance teams, machine tool operators, and service engineers, understanding SW alarms is important because parameter write settings directly affect CNC... Read more...
FANUC CNC Alarm Codes (1001 and Above)
This page covers FANUC CNC alarm codes 1001 and above for: FANUC Series 0i-Model D FANUC Series 0i Mate-Model D These alarm references may appear as: PS alarms – Program-related alarms BG alarms – Background editing alarms SR alarms – Communication alarms Important: PS, BG, and SR alarms use the same shared numeric alarm code system.The alarm number alone does not identify the alarm type. The actual prefix is displayed only on the CNC system screen, such as PS1001, BG1095, or SR2032. This page is useful for: CNC operators Maintenance... Read more...
FANUC CNC Alarm Codes (0401–1000)
This page continues the FANUC alarm reference for alarm numbers 0401–1000. These alarm references apply to: FANUC Series 0i-Model D FANUC Series 0i Mate-Model D The alarms in this section may appear as: PS alarms – Program-related alarms BG alarms – Background editing alarms SR alarms – Communication alarms Important: PS, BG, and SR alarms share the same numeric alarm code system.The number alone does not identify the alarm type. The actual prefix is shown only on the CNC screen, such as PS0412, BG0518, or SR0601. This page is useful... Read more...
FANUC CNC Alarm Codes (0201–0400)
This page continues the FANUC alarm reference for alarm numbers 0201–0400. These alarm references apply to: FANUC Series 0i-Model D FANUC Series 0i Mate-Model D The alarms in this section may appear as: PS alarms – Program-related alarms BG alarms – Background editing alarms SR alarms – Communication alarms Important: PS, BG, and SR alarms share the same numeric alarm codes.That means the number alone does not identify the alarm type. The actual prefix is displayed only on the CNC screen, such as PS0201, BG0233, or SR0085. This page is... Read more...
FANUC CNC Alarm Codes List (0001–0200)
FANUC CNC Alarm Codes (0001–0200) FANUC CNC alarm codes from 0001 to 0200 are some of the most frequently searched and most commonly encountered alarms in daily CNC programming, editing, and machine operation. This page covers alarm numbers that may appear as: PS alarms – Program-related alarms BG alarms – Background editing alarms SR alarms – Communication alarms These alarm references apply to: FANUC Series 0i-Model D FANUC Series 0i Mate-Model D This reference page is designed for: CNC machine operators Maintenance engineers FANUC service technicians CNC programmers Spare parts... Read more...
FANUC CNC Alarm Codes (PS / BG / SR Alarms)
What are PS, BG, and SR alarms? FANUC CNC alarms are displayed with prefixes such as: PS – Program-related alarms BG – Background editing alarms SR – Communication alarms Examples: PS0003 BG0085 SR0001 Browse FANUC Alarm Codes by Range FANUC Alarm Codes 0001–0200 FANUC Alarm Codes 0201–0400 FANUC Alarm Codes 0401–1000 FANUC Alarm Codes 1001+ Common FANUC Alarm Searches Users often search for: Common FANUC CNC Alarms Classification FANUC Common Over Travel Alarm List FANUC G/ M Code for a Machining Center FANUC G/ M Code for lathe How to... Read more...
Complete FANUC Spindle Alarm Codes (SP9110–SP9216)
This page provides the complete FANUC serial spindle alarm list (final section), covering alarm codes from SP9110 to SP9216. These alarms mainly relate to: Power supply (PS) faults Communication errors Safety system issues Hardware failures and protection functions This section is essential for advanced troubleshooting and maintenance of FANUC CNC systems. FANUC Spindle Alarm List (SP9110–SP9216) 1) SP9110 – SP9113 Alarm Code Message Amplifier Display Cause Troubleshooting SP9110 Amplifier Communication Error B0 Communication failure between spindle amplifier and power supply Replace communication cable or unit SP9111 Inverter Control Voltage Low... Read more...
FANUC Spindle Alarm Codes (SP9034–SP9092)
This page continues the FANUC serial spindle alarm list, covering alarm codes from SP9034 to SP9092. These alarms mainly involve: Parameter errors Encoder and sensor faults Spindle synchronization issues Communication and hardware failures Understanding these alarms helps reduce downtime and improve CNC machine reliability. FANUC Spindle Alarm List (SP9034–SP9092) 1) SP9034 – SP9043 Alarm Code Message Amplifier Display Cause Troubleshooting SP9034 SSPA:34 Parameter Illegal 34 Parameter value exceeds allowable range Refer to parameter manual and correct values SP9036 SSPA:36 Error Counter Overflow 36 Position error counter overflow Reduce position gain... Read more...
FANUC Serial Spindle Alarm Codes (SP9001–SP9033)
When a serial spindle alarm occurs in a FANUC CNC system, the CNC displays an alarm number for diagnosis. If the red LED on the spindle amplifier lights up, a two-digit alarm code is shown. ⚠️ Important Notes: A yellow LED indicates a sequence-related issue, not a hardware fault Example: spindle rotation command issued while emergency stop is active Alarm meanings differ depending on LED status For alarm codes not listed here, refer to: FANUC AC Spindle Motor αi Series Maintenance Manual (B-65285EN) FANUC Spindle Alarm List (SP9001–SP9033) 1) SP9001 –... Read more...

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