E2-52

Internal Error (SM560-S)

ABB · AC500-S Safety Controller

What does E2-52 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

  • Unspecified internal hardware fault within the SM560-S module (e.g., CPU, bus, ASIC failure).
  • Severe corruption of the operating system or bootloader firmware.
  • Transient power disturbance affecting internal logic leading to an unrecoverable state.
  • Overheating of internal components due to inadequate cooling within the control cabinet.
  • External electromagnetic interference (EMI) causing critical internal register corruption.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    1. Cycle power to the SM560-S Safety PLC by turning off and on the 24VDC supply for at least 10 seconds.

  2. 2

    2. Check the event log or diagnostic buffer in the engineering software for any preceding warnings or associated sub-codes.

  3. 3

    3. Monitor the PLC's internal temperature via diagnostic tools (if available) to ensure it is within the specified operating range (e.g., 0-55°C).

  4. 4

    4. Attempt to re-download the latest compatible firmware for the SM560-S module.

  5. 5

    5. Replace the SM560-S Safety PLC module if the internal error persists after power cycling and firmware update.

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Verified technical data. Last updated: March 2026

Related Faults

Source: ABB AC500-S Safety Controller