GE Dishwasher Error Code LOCK LED illuminated + continuous beeping (Factory Test Mode)

The LOCK LED illuminated with continuous beeping on a GE dishwasher indicates a turbidity sensor check failure during the factory test mode sequence. Factory test mode runs a series of automated checks across the dishwasher's major systems and components. When the turbidity sensor check fails within this sequence, the control module triggers the LOCK LED and continuous beeping as a diagnostic alert to signal that the sensor circuit has not returned the expected signal or value.

The turbidity sensor is responsible for detecting how dirty the wash water is by measuring the amount of light that passes through a sample of water during the cycle. The control module reads the sensor's output and uses that data to adjust wash times and rinse cycles accordingly. If the sensor fails to communicate properly with the control module during the factory test, the cause may be a faulty sensor, a break or short in the wiring harness connecting the sensor to the control board, or a defective control module that cannot correctly interpret the sensor's signal.

The first step after this alert appears is to press any keypad button to stop the beeping and exit the active alarm state. From there, a full diagnostic should cover the turbidity sensor itself, the wiring harness and connectors between the sensor and the control board, and the control module. Any damaged wiring insulation, corroded connectors, or a sensor reading outside its expected parameters would confirm the source of the failure.