Samsung Washer Error Code AC3

AC3 indicates a communication error between the Inverter PBA and the main PBA. These two control boards must exchange signals to operate the wash motor, and when that communication is lost or interrupted, the washer displays AC3 and stops running. The cause is often a loose or poorly seated wiring harness connector, though faulty soldering or a defective board can also be responsible.

A reset may temporarily clear the display, but if the underlying connection problem or board fault is still present, the AC3 code will return as soon as the washer attempts to operate the motor. A reset is a reasonable first step, but it should be followed by a proper inspection of the Inverter PBA to main PBA wiring harness.

If the fix is simply reseating a loose connector, there is no parts cost and only minimal labor time involved. If the Inverter PBA needs replacement, parts and labor typically run in the range of $150 to $350 depending on the model and service rates in your area. Main PBA replacement tends to be at the higher end of that range or above, which may factor into a repair-versus-replace decision on older machines.

In many cases, yes. Start by unplugging the washer, then locate the wiring harness that runs between the Inverter PBA and the main PBA and check that both ends are firmly and correctly connected. If connections look good, inspect the solder joints on the connector terminals for any cracks or cold joints. If the error returns after confirming solid connections, board replacement is likely needed and may require a technician.

No. The AC3 error means the washer cannot properly control its motor, and running it in this state risks damaging the motor drive components or causing an incomplete cycle. Keep the washer unplugged until the communication fault is diagnosed and resolved.