GE Dishwasher Error Code 999: Floor Protect Leak Sensor... | appliancefaults.com

Technical Background:

The MCU (Main Control Unit) monitors the floor protect leak sensor circuit. The sensor is designed to detect the presence of water in the dishwasher's base pan. When water is detected, the sensor signals the MCU, which triggers the error code and shuts down the dishwasher to prevent further water damage. The voltage path from the MCU to the sensor and back must be intact for proper operation.

Symptoms:

The GE dishwasher displays error code 999 and may not start or may stop mid-cycle. You might find water accumulating under the dishwasher. The error may appear intermittently or constantly.

Possible Causes:

Faulty floor protect leak sensor
Water detected in the base pan
Wiring harness damage to the sensor
MCU (Main Control Unit) malfunction
Drain pump issues causing excessive water
Blocked drain line creating backflow

Solution:

1

Turn off power to the dishwasher at the breaker panel. Verify power is off with a non-contact voltage tester at the dishwasher junction box (120V AC).
2

Remove the lower access panel using a 1/4-inch nut driver.
3

Inspect the base pan for standing water. If water is present, dry it thoroughly with towels.
4

Locate the floor protect leak sensor. It's typically a small, rectangular sensor near the front of the base pan.
5

Disconnect the wiring harness from the leak sensor. Inspect the connector and wiring for damage or corrosion.
6

Use a multimeter to test the sensor. The resistance should change when the sensor is exposed to moisture. If the sensor reads open or shorted, replace it.
7

Install the new floor protect leak sensor, reconnect the wiring harness, and reassemble the access panel. Restore power at the breaker panel.

Safety Warning:

Disconnect power to the appliance before performing any repairs. Use caution when working with electrical components. If you are not comfortable working with electricity, consult a qualified appliance repair technician. Lock Out/Tag Out (LOTO) procedures MUST be followed. High Voltage Present.

Prevention:

Regularly check and clean the dishwasher's drain filter and spray arms. Inspect the door seal for damage and replace if necessary. Avoid overloading the dishwasher to prevent food debris from clogging the drain system.

Expert Tip:

After replacing the sensor, run the dishwasher through a full cycle and monitor for any leaks. You can sometimes enter a service mode by pressing and holding certain button combinations (check the service manual for your specific model) to clear the error code manually after the sensor is replaced.

Frequently Asked Questions

•How do I test the floor protect leak sensor with a multimeter?

Set your multimeter to the resistance (Ohms) setting. With the sensor dry, you should read a high resistance (typically Megaohms). When you apply a drop of water to the sensor, the resistance should drop significantly (typically to a few Kohms or less).

•Where can I find the replacement floor protect leak sensor?

You can find the replacement sensor at most appliance parts retailers or online. Be sure to order the correct part number for your specific GE dishwasher model. Check the appliance's model number on the unit's chassis for a correct match.

•What if I replace the sensor and the error code 999 still appears?

If the error persists after replacing the sensor, the issue may be with the wiring harness, the drain pump, or the MCU. Inspect the wiring for damage, check the drain pump for proper operation, and if necessary, consult a qualified technician to diagnose and repair the MCU.

GE Dishwasher Error Code 999: Floor Protect Leak Sensor Replacement Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I test the floor protect leak sensor with a multimeter?

•Where can I find the replacement floor protect leak sensor?

•What if I replace the sensor and the error code 999 still appears?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: