LG Washer Error Code AC5

AC5 on an LG washer signals a communication error between the Inverter PBA and the main PBA. The two control boards are not exchanging signals as expected, which causes the washer to stop operating. This is often traced to a loose connector, corroded pins, or a faulty solder joint rather than a fully failed board.

No, you should not continue running the washer while AC5 is active. The error indicates the motor control system is not communicating correctly, and operating the machine in this state could cause unpredictable motor behavior or further damage to the control boards. Power the washer off and address the fault before resuming use.

If the fix is simply reseating a loose connector, the cost is limited to a service call fee, typically in the range of $75 to $150. If the Inverter PBA or main PBA requires replacement, parts and labor combined can range from $200 to $450 or more depending on the specific model and local labor rates. Getting a diagnostic assessment before authorizing board replacement is recommended.

A knowledgeable DIYer can attempt to resolve AC5 by inspecting and reseating the connectors between the Inverter PBA and the main PBA. Unplug the washer before opening the cabinet, locate both boards, and firmly press each connector until it clicks into place. If the error returns after reseating connections, the repair likely requires soldering skills or board replacement, which is better suited to a qualified technician.

A reset may temporarily clear the AC5 code if the fault was caused by a minor signal glitch, but if a loose connector or damaged solder joint is the underlying cause, the error will return during the next cycle. To clear the code permanently, the physical connection problem between the Inverter PBA and main PBA must be identified and corrected.