SV0368Servo alarm · Pulsecoder (encoder) / feedbackUsually repairable
Fanuc αi SV0368: Serial Data Error (Built-In)
Also shown as: 16i/18i/21i/0i: 368
What SV0368 means
The CNC is not receiving valid serial data from the motor's built-in Pulsecoder (encoder).
Symptoms
Alarm at power-on or while the axis moves; sometimes intermittent with cable movement.
Is it repairable?
Yes: Pulsecoder replacement and alignment are standard repairs.
Common causes
- Damaged feedback cable or connector
- Coolant in the encoder connector
- Failed Pulsecoder
- Faulty feedback interface in the amplifier
Safe checks
- 1Inspect the feedback cable and connectors for damage or coolant
- 2Try a known-good cable
Drives hold dangerous voltage after power-off. Checks should only be done by qualified personnel, with power isolated and the DC link discharged.
Reviewed by AutomIQ repair technicians. Code and name from the FANUC αi series Maintenance Manual.
Related Fanuc αi faults
- SV0401V ready off
- SV0433DC link undervoltage
- SV0436Soft thermal (OVC)
- SV0438motor current alarm
- SV0442DC link precharge failure
- SV0443cooling fan stopped