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

Technical Background:

MCU logic and voltage paths.
The main control unit (MCU) monitors the pressure sensor to determine the water level inside the dishwasher. The pressure sensor sends a voltage signal back to the MCU. The MCU then uses this signal to determine when to stop filling the dishwasher and when to activate other functions. A fault in the sensor, wiring, or MCU can cause the error code.

Symptoms:

US homeowner observations.
The dishwasher displays error code 999. The dishwasher may not fill properly, may stop mid-cycle, or may continuously run the drain pump.

Possible Causes:

Faulty pressure sensor.
Leak in the pressure sensor hose or connection.
Wiring harness issue between the pressure sensor and the main control board.
Defective main control board (MCU).
Low water pressure to the dishwasher.
Clogged filter restricting water flow.

Solution:

1

Disconnect power to the dishwasher at the breaker panel. Lock Out/Tag Out (LOTO) procedure.
2

Locate the pressure sensor. It's usually in the sump area or near the circulation pump.
3

Inspect the pressure sensor and its hose for any visible leaks or damage.
4

Disconnect the wiring harness from the pressure sensor. Use a multimeter to check for continuity and voltage (typically 5V DC) at the harness connector with the dishwasher powered on (briefly, then disconnect power again immediately).
5

Check the pressure sensor's resistance using a multimeter. Consult the service manual for the correct resistance range. Typically, you are looking for a changing resistance as the water level changes.
6

Inspect the wiring harness for any damage or loose connections.
7

If the pressure sensor and wiring are good, the main control board (MCU) may be faulty. Consider replacing the MCU.

Safety Warning:

Always disconnect power to the appliance at the breaker panel before performing any repairs. High voltage is present in the control panel and can cause serious injury or death. Follow Lock Out/Tag Out (LOTO) procedures.

Prevention:

• Regularly clean the dishwasher's filters to prevent clogs.
• Check the water supply line for kinks or obstructions.
• Use the correct amount of detergent to prevent excessive suds.

Expert Tip:

To enter service mode on some GE dishwashers, press and hold the Start and Select Cycle buttons simultaneously for 5 seconds. This allows you to run diagnostic tests and view error history. This can help isolate the problem.

Frequently Asked Questions

•What is the typical resistance range for the pressure sensor on my GE dishwasher?

The typical resistance range varies by model. Consult the service manual for your specific GE dishwasher model. The resistance will change as the water level changes. Usually you'll see a few hundred to a few thousand ohms.

•How do I test the water inlet valve to ensure it's functioning correctly?

First, disconnect power to the dishwasher. Then, disconnect the water supply line. Use a multimeter to check the solenoid valve for continuity. If there's no continuity, the valve is likely faulty. You can also apply 120V AC to the valve terminals briefly to see if it opens. Be careful! If the valve doesn't open with power applied, it needs replacing.

•Where can I find the service manual for my specific GE dishwasher model?

You can often find service manuals online by searching for the model number followed by 'service manual' or 'technical sheet.' Websites like AppliancePartsPros or RepairClinic may have them available for download. You can also check the GE Appliances website.

GE Dishwasher Error Code 999: Pressure Sensor Leak Inspection Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical resistance range for the pressure sensor on my GE dishwasher?

•How do I test the water inlet valve to ensure it's functioning correctly?

•Where can I find the service manual for my specific GE dishwasher model?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: