Samsung · Dishwasher Moderate

AC — Display/Main Board Communication Error

A communication error between the display board and the main PCB. The dishwasher powers up but the boards can't talk to each other, so cycles won't start. This is a board/harness issue, not a door-latch fault.

Keep using it?
Yes, with caution
DIY difficulty
Moderate

How to fix it

  1. Power off at the breaker for 1 minute and restore — a reseated connection sometimes clears the error on restart.
  2. Open the lower kick panel and locate the harness run between the display board and the main PCB.
  3. Unplug and firmly reseat the connector at both the display board and main PCB ends.
  4. Inspect the harness for chafing, pinching, or corrosion; replace if damaged.
  5. If the error returns with a known-good harness, replace the display board first, then the main PCB if it persists.

Why it happens

Typical signs: AC on display or controls unresponsive · Powers on but won't start or run cycles · Lights on but no start · Buttons feel mushy or unresponsive

  • Loose harness between display board and main PCB Connector at either end has vibrated or worked loose.
  • Failed display board Display board not transmitting/receiving on the comm line.
  • Failed main PCB Main board's comm side has failed.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

  • Samsung dishwasher display/control board Common replacement
    Amazon →
  • Samsung dishwasher main control board Common replacement
    Amazon →

More Samsung dishwasher codes

1C 1C — Low water level / fails to start 1E 1E / IE — Filter clogged / heater fault 3C 3C Error — Wash Pump Failure 3E 3E — Hot water supply too hot 4C 4C / 4E — Water Supply Error 4C5 4C5 / 4E5 — Fill timeout with dry tub

All Samsung codes → All dishwasher codes →

Frequently asked questions

What does the AC code mean on a Samsung dishwasher?

A communication error between the display board and the main PCB. The dishwasher powers up but the boards can't talk to each other, so cycles won't start. This is a board/harness issue, not a door-latch fault.

What causes the AC code on a Samsung dishwasher?

Loose harness between display board and main PCB: Connector at either end has vibrated or worked loose. Failed display board: Display board not transmitting/receiving on the comm line. Failed main PCB: Main board's comm side has failed.

Is it safe to keep using a Samsung dishwasher with a AC error?

Yes, with caution. This is rated a moderate-severity fault.

How do I fix AC on a Samsung dishwasher?

Power off at the breaker for 1 minute and restore — a reseated connection sometimes clears the error on restart. Open the lower kick panel and locate the harness run between the display board and the main PCB. Unplug and firmly reseat the connector at both the display board and main PCB ends.

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.