What causes Okuma OSP alarm 4173?

VAC motor cooling fan failed or heat sink clogged with chips/oil mist. Frequent high-speed CW/CCW reversals (rigid tapping, high-duty jogging) heating the motor. Failing BL motor with internal heat buildup. Faulty motor encoder misreporting temperature (BL motor overheat is detected via the encoder).

How do I fix Okuma OSP alarm 4173?

1. Read the code number shown with the alarm: code 0010 = Motor overheat detected; code 0011 = Overheat detected at the motor itself; code 0012 = Overheat detected at the position encoder; code 0013 = Overheat detected at both the motor and the encoder 2. Read the code's last four digits: 0010 = motor overheat, 0011 = detected at the motor, 0012 = detected at the position encoder, 0013 = detected at both motor and encoder - this tells you where to look first. 3. Let the motor cool, then inspect the VAC motor cooling fan for operation and clean the heat sink of chips, sludge, and oil mist. 4. Review the recent duty: repeated high-frequency CW/CCW starts and stops will overheat the motor - allow cool-down time or reduce the cycle duty. 5. If code 0012 or 0013 (encoder detection) appears with a cool motor, suspect the motor encoder or its cable rather than genuine overheating. 6. If the motor is genuinely hot at light duty after cleaning and fan checks, the BL motor itself is likely failing - contact Okuma service with the recorded code and axis name.

Okuma OSP codes

axismd.ai

Okuma OSP Controller

Overheat/Thermal · Intermediate

Alarm 4173

Okuma OSP Alarm D 4173 - MCS Motor overheat

The control detected an abnormally high temperature in the axis or spindle motor named in the object field. The code identifies where the overheat was sensed: at the motor itself, at the position encoder, or both (BL motors sense overheat through the encoder).

Okuma OSPOverheat/ThermalIntermediate

4173

Okuma OSP Alarm D 4173 - MCS Motor overheat

MCS Motor overheat

Common Causes

VAC motor cooling fan failed or heat sink clogged with chips/oil mist
Frequent high-speed CW/CCW reversals (rigid tapping, high-duty jogging) heating the motor
Failing BL motor with internal heat buildup
Faulty motor encoder misreporting temperature (BL motor overheat is detected via the encoder)

Troubleshooting Steps

1Read the code number shown with the alarm: code 0010 = Motor overheat detected; code 0011 = Overheat detected at the motor itself; code 0012 = Overheat detected at the position encoder; code 0013 = Overheat detected at both the motor and the encoder
2Read the code's last four digits: 0010 = motor overheat, 0011 = detected at the motor, 0012 = detected at the position encoder, 0013 = detected at both motor and encoder - this tells you where to look first.
3Let the motor cool, then inspect the VAC motor cooling fan for operation and clean the heat sink of chips, sludge, and oil mist.
4Review the recent duty: repeated high-frequency CW/CCW starts and stops will overheat the motor - allow cool-down time or reduce the cycle duty.
5If code 0012 or 0013 (encoder detection) appears with a cool motor, suspect the motor encoder or its cable rather than genuine overheating.
6If the motor is genuinely hot at light duty after cleaning and fan checks, the BL motor itself is likely failing - contact Okuma service with the recorded code and axis name.

Seeing Multiple Alarms?

Seeing another alarm with this one? Enter the code.

Get machine-aware diagnosis

AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.

Start free

Was this guide helpful?

Always verify with your machine manual or a certified technician before performing service procedures.