GE Dishwasher Error Code LOCK LED illuminated (Factory Test)

This indicates that the turbidity sensor failed its check during factory test mode. The turbidity sensor measures water clarity to help the dishwasher adjust its wash cycle. When the test detects no valid signal from the sensor, the control module illuminates the LOCK LED and beeps to flag the fault. The control module, wiring harness, and turbidity sensor are all considered suspect until each is inspected.

The LOCK LED fault is triggered during factory test mode, not during a standard wash cycle, so the dishwasher may still operate for normal use. However, a failed turbidity sensor means the appliance cannot accurately monitor water soil levels, which can reduce wash performance. It is best to have the fault diagnosed and repaired before relying on the dishwasher for regular use.

Repair costs depend on which component has failed. A turbidity sensor replacement typically falls in the range of $30 to $80 for the part alone, while a control module can range from $100 to $250 or more depending on the model. Adding professional labor will increase the total cost. Inspecting the wiring harness first is worthwhile, since a loose connector or damaged wire can sometimes be corrected at little or no parts cost.

A knowledgeable DIYer can perform initial checks such as cleaning the turbidity sensor's optical window and inspecting the wiring harness for loose or corroded connectors. If those steps do not resolve the fault, replacing the turbidity sensor or control module typically requires correctly identifying the failed component first. Misdiagnosis can lead to unnecessary part purchases, so methodical testing of each suspect component is important before ordering replacements.

A power reset will not correct the underlying hardware fault causing the turbidity sensor check to fail. The error will return whenever factory test mode is run again because the control module, wiring, or sensor still has a defect. The fault must be resolved by identifying and repairing or replacing the failed component.