Code SP0037: Speed detector parameter error
Issue Description & Safety Warning
The Fanuc Alpha-i Servo Spindle Amplifier has triggered a critical Speed detector parameter error 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
Amplifier LED display: 37 Also shown as: SP0037 (15i), SP9037 (30i/31i/32i), SP9037 (0i-D) Cause: After emergency stop signal input, the motor is accelerated without being decelerated. This alarm is issued also when the motor is not deactivated (the motor is not decelerated completely) when the acceleration/deceleration time (initial parameter setting: 10 seconds) has elapsed after emergency stop signal input. Troubleshooting when this alarm is issued (a) The parameter setting of the speed detector is incorrect. Referring to Chapter 1 in "FANUC AC SPINDLE MOTOR αi series Parameter Manual (B-65280EN)," set a correct time. (b) The parameter setting of an acceleration/deceleration time is not proper. Check the parameter-set value and actual acceleration/ deceleration time, then set an actual acceleration/deceleration time plus some margin. FS15i FS16i FS0i-B/C FS30i FS0i-D Description 3082 4082 4082 Acceleration/deceleration time setting
Source: Fanuc αi Servo/Spindle Amplifier Maintenance Manual (B-65285EN/04) — Part II Troubleshooting
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Fanuc Alpha-i Servo Spindle Amplifier Alarms
Fanuc controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code SP0037 on the Alpha-i Servo Spindle Amplifier identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Fanuc's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 135 Fanuc Alpha-i Servo Spindle Amplifier codes.
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