1006
CPU Down Error
Mitsubishi Electric · MELSEC System Q/L Series
What does 1006 mean?
The CPU module has experienced a runaway condition or failure, potentially due to electrical noise interference or a fundamental hardware fault within the module. This condition indicates the CPU is no longer operating correctly.
Common Causes
- Runaway or failure of CPU module.
- Malfunctioning due to noise or other external reasons.
- Hardware fault within the CPU module.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Implement noise reduction measures for the control system environment.
- 2
Reset the CPU module and attempt to RUN it again.
- 3
If the same error is displayed again after resetting, diagnose for a CPU module hardware fault.
Verified technical data. Last updated: March 2026
Related Faults
Source: Mitsubishi Electric MELSEC System Q/L Series