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ABB Error 39520 — Communication lost with drive module

Error

ABB 39520 (“Communication lost with drive module”): Communication lost with drive module: the main computer has lost contact with the indicated drive module. Likely part: Liaison Ethernet Control Module / Drive Module (link Ethernet Control Module / Drive Module).

Updated 2026-10-22 · LogrobotLM reference

What it means

Communication lost with drive module: the main computer has lost contact with the indicated drive module. Goes to SYS HALT, no operation possible until corrected.

What to check

  • Check that the drive module main switch is switched on.
  • Check the Ethernet cable between the Control Module and the Drive Module as well as both connectors.
  • Check that there are no sources of interference along the cable route.
  • Note: Dual-module architecture specific to IRC5. See 39521 (warning level) and 39522 (axis computer not found).

Part to check / replace

ABB 39520 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

32540Drive unit / firmware fault32541Drive unit / firmware fault39008Drive units fault

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 →