FANUC Alarm 414 — Servo Alarm: N-Axis Excess Error
What This Fault Means
Alarm 414 (SV0414) triggers when the difference between the commanded position and actual position of a servo axis exceeds the threshold set in parameter 1828. The CNC halts axis motion.
Common Causes
- Mechanical binding or collision on the axis
- Servo motor encoder cable damaged or disconnected
- Servo amplifier fault or low bus voltage
- Ball screw wear causing excessive backlash
- Gains too low for the axis load (parameter 1825/1826)
Recommended Fix
- Jog the axis slowly — if it moves but alarms at speed, check the servo gains and mechanical resistance.
- Inspect the encoder cable for damage, especially at flex points.
- Check the servo amplifier for alarm LEDs (refer to amplifier manual for codes).
- Measure backlash on the ball screw and compare to machine specification.
- Temporarily increase the excess error threshold (parameter 1828) to diagnose, but restore it after.
Still stuck? Ask Mira.
Paste your fault code into Mira and get an answer from your actual equipment manuals in seconds.
Try free