E2-25
Internal Error (SM560-S)
ABB · AC500-S Safety Controller
What does E2-25 mean?
The SM560-S Safety PLC has encountered an unspecified internal error. This indicates a system malfunction that prevents normal operation and requires intervention.
Common Causes
- Internal hardware malfunction of the SM560-S, possibly related to memory or internal communication.
- Firmware corruption, rendering the PLC unable to execute its internal routines correctly.
- Transient voltage instability on the 24VDC supply rail causing CPU logic errors.
- Unexpected software exception within the Safety PLC's operating system.
- Component aging leading to intermittent internal failures.
Repair Steps & Checklist
Click steps to track your progress.
- 1
1. Execute a full power down and restart of the entire control system, including the SM560-S module.
- 2
2. Check for any overheating indicators on the SM560-S module or in its immediate enclosure.
- 3
3. Verify the consistency between the loaded project in the PLC and the project on the engineering workstation.
- 4
4. Update the SM560-S firmware to the latest available version from the manufacturer's website.
- 5
5. Replace the SM560-S Safety PLC module if the error cannot be resolved through power cycling and software actions.
Verified technical data. Last updated: March 2026
Related Faults
Source: ABB AC500-S Safety Controller