Viking Dishwasher Error Code NORMAL WASH + LED4

This code signals a communication error between the User Interface board and the machine control board. The two boards have lost their data connection, which prevents the dishwasher from operating normally. The first place to check is the wiring harness that links the two boards together.

A power reset may temporarily clear the error, but if the underlying wiring or board fault is still present the code will return. Resetting is a reasonable first step to rule out a transient glitch, but a persistent error requires physical inspection of the harness and control boards.

If the fix is simply reseating a loose connector, the cost may only involve a service call fee, typically in the range of $75 to $150. If a wiring harness needs replacement, costs generally fall in the $100 to $250 range including parts and labor. A control board replacement is more involved and can range from $200 to $500 or more depending on the specific board and labor rates in your area.

Start by inspecting the harness connector between the UI board and the machine control board for loose, damaged, or corroded connections. Reseat any loose connectors and examine the wiring for breaks or fraying. If the harness is in good condition, one of the two control boards may need to be replaced, which typically requires a technician.

The dishwasher will not complete a normal cycle while this error is active because the control boards cannot communicate properly. It is best to leave the unit unpowered until the fault is diagnosed and repaired to avoid any risk of an incomplete or uncontrolled cycle.