1172
RAM ERROR
Mitsubishi Electric · MELSEC System Q/L Series
What does 1172 mean?
The RAM of the CPU module (built-in I/O) is faulty. This error indicates a hardware problem with the internal memory specifically allocated for built-in I/O functions within the CPU module. It is detected at power ON or during a system reset.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Take noise reduction measures.
Verified technical data. Last updated: March 2026
Related Faults
Source: Mitsubishi Electric MELSEC System Q/L Series