Frigidaire Dishwasher Spray Arm Diverter Motor Failure:... | appliancefaults.com

Technical Background:

The Main Control Unit (MCU) controls the diverter motor, which directs water flow between the upper and lower spray arms. The MCU sends a 120V AC signal to the motor based on the wash cycle stage. If the motor fails, water distribution is compromised. Voltage is sent from the MCU to the motor on a specified pin within the wiring harness.

Symptoms:

Homeowners often report dishes not being cleaned properly, particularly on one rack versus the other. They might also hear strange noises or notice the wash cycle is unusually long. The spray arm might not appear to be moving, or it might move erratically.

Possible Causes:

Faulty diverter motor.
Wiring harness issue (loose connection or damaged wire).
Failed MCU relay.
Debris obstructing the diverter valve.
Clogged spray arms reducing water pressure.
Low water pressure to the dishwasher.

Solution:

1

Disconnect power to the dishwasher at the breaker panel. Verify no voltage is present using a non-contact voltage tester.
2

Locate the diverter motor, usually near the sump. Consult the dishwasher’s service manual for exact location.
3

Remove the diverter motor cover using a 1/4-inch nut driver or a Torx bit (size may vary). Disconnect the wiring harness.
4

Using a multimeter set to AC voltage, check for 120V AC at the diverter motor connector during the portion of the cycle when it should be active. Activate the wash cycle and verify the voltage. Use caution when measuring live voltage.
5

If voltage is present but the motor isn't running, the motor is likely faulty. Replace the diverter motor.
6

If no voltage is present, check the wiring harness for continuity and shorts to ground. Inspect the MCU for damage or failed relays.
7

Reassemble the dishwasher and test its operation through a full wash cycle.

Safety Warning:

Always disconnect power to the dishwasher before performing any repairs. Lock Out/Tag Out (LOTO) procedures must be followed. Be aware of high voltage (120V AC) when testing electrical components.

Prevention:

Regularly clean the dishwasher filter to prevent debris from entering the diverter valve. Avoid overloading the dishwasher, which can reduce water pressure and cleaning effectiveness. Use a dishwasher cleaner monthly to remove buildup. Periodically check the spray arms for clogs and clean them as needed.

Expert Tip:

Some Frigidaire dishwashers have a service mode that allows you to manually activate the diverter motor for testing. Consult the service manual for the specific sequence to enter service mode and activate the motor. You may need to press a combination of buttons (e.g. High Temp Wash + Start/Cancel) to enter the service mode.

Frequently Asked Questions

•How do I access the diagnostic mode on my Frigidaire dishwasher?

The diagnostic mode varies by model. Consult your service manual, but a common method is pressing a sequence of buttons like 'High Temp Wash' and 'Start/Cancel' within a few seconds. The control panel lights will usually indicate entry into diagnostic mode.

•What is the correct replacement part number for my Frigidaire dishwasher diverter motor?

The part number depends on your specific model number. Locate the model number on the dishwasher (usually inside the door or on the side panel). Then, use that model number to search for the correct diverter motor on a parts website like AppliancePartsPros.com or RepairClinic.com. Alternatively, call a local appliance parts distributor.

•What voltage should I expect to see at the diverter motor connector when it's supposed to be running?

You should typically measure 120V AC at the diverter motor connector when the MCU is signaling the motor to activate. If you measure significantly less voltage, suspect a wiring issue or a problem with the MCU.

Frigidaire Dishwasher Spray Arm Diverter Motor Failure: Symptoms and Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the diagnostic mode on my Frigidaire dishwasher?

•What is the correct replacement part number for my Frigidaire dishwasher diverter motor?

•What voltage should I expect to see at the diverter motor connector when it's supposed to be running?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: