ABB Error 71058 — I/O unit communication lost
ErrorABB 71058 (“I/O unit communication lost”): An I/O unit stopped answering on its industrial network. Likely part: Unité d'E/S / Bus d'E/S (Unité d'E/S / Bus d'E/S).
Updated 2026-09-17 · LogrobotLM reference
What it means
An I/O unit stopped answering on its industrial network. All its signals freeze — downstream logic may block the cell.
What to check
- Check the unit's power supply first (24 V dips are the most common cause).
- Inspect network cabling/connectors to the unit; check the bus status LEDs.
- If several units drop together: look at the shared segment (switch, trunk, PSU), not the units.
Part to check / replace
ABB 71058 points to the hardware below — start here before ordering.
Tap a part for every code that points to it — and verify the exact variant for your controller before ordering.
Related codes
Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →