LG Washer Error Code 1AC

The 1AC code indicates a communication error between the sub printed board and the main printed board in the upper washer unit. The main board is not detecting the expected signals from the sub board, which causes the machine to stop operating. This fault is specific to LG twin or combo washer configurations where an upper washer unit is present.

A power reset may temporarily clear the code, but it will return if the underlying communication problem is not resolved. The boards must be able to exchange signals consistently for the error to stay cleared. Address the root cause, such as a loose connector or faulty board, before expecting the code to remain gone.

Repair costs vary depending on what is causing the fault. If the fix is simply reseating a connector, the cost may only involve a service call fee, typically in the range of $75 to $150. If a wiring harness or one of the printed boards needs replacement, total repair costs including parts and labor can range from $150 to $400 or more depending on the specific board required and local labor rates.

If the cause is a loose connector, a knowledgeable DIYer can often reseat the connections between the sub and main boards without special tools. However, if the wiring harness is damaged or one of the boards has failed, the repair becomes more complex and a technician may be needed to safely diagnose and replace the correct component.

It is not recommended to continue using the washer while the 1AC code is active. The communication failure between the boards means the machine cannot properly coordinate its functions, which could lead to incorrect cycle behavior or additional component damage. Resolving the fault before running laundry cycles is the safer approach.