Kenmore Dishwasher Error Code 8-4: Drain Pump Electrical... | appliancefaults.com

Technical Background:

error code 8-4 indicates that the main control unit (MCU) has detected an electrical fault in the drain pump circuit. The MCU monitors the current draw of the drain pump. If the current is too high or too low, it signals a fault. This can be due to a short circuit, open circuit, or a pump motor that is drawing excessive current. The voltage path typically runs from the breaker panel to the control board, then through a relay to the drain pump.

Symptoms:

The dishwasher displays error code 8-4. The dishwasher may not drain water. The drain pump may not run or may run intermittently. There might be a burning smell emanating from the unit.

Possible Causes:

Faulty drain pump.
Wiring harness issue between the drain pump and the control board.
Tripped high-limit thermostat.
Failed drain pump relay on the control board.
Clogged drain hose restricting pump operation causing electrical overload.
Loose wiring connection at the drain pump or control board.

Solution:

1

Disconnect power to the dishwasher at the breaker panel.
2

Locate the drain pump, typically at the bottom of the dishwasher tub. Access it by removing the lower access panel using a 1/4-inch nut driver.
3

Inspect the wiring harness connected to the drain pump for any signs of damage, corrosion, or loose connections.
4

Use a multimeter to check the drain pump's resistance. A typical drain pump should read between 10-20 ohms.
5

If the drain pump resistance is outside the specified range, replace the drain pump.
6

Check the voltage to the drain pump when the dishwasher is in the drain cycle. You should read approximately 120V AC.
7

If the voltage is not present, inspect the drain pump relay on the control board and the wiring between the control board and the drain pump. Replace the control board if the relay is faulty.

Safety Warning:

Disconnect power to the dishwasher at the breaker panel before performing any repairs. Lock Out/Tag Out (LOTO) procedures must be followed to prevent accidental energizing of the circuit. High voltage is present in the dishwasher, take caution to avoid electrical shock.

Prevention:

Periodically clean the drain filter to prevent clogs. Inspect the drain hose for kinks or obstructions. Run a dishwasher cleaner cycle monthly.

Expert Tip:

After replacing the drain pump, run the dishwasher through a complete cycle to ensure proper operation and to clear any remaining water. Some Kenmore dishwashers have a service mode that can be accessed by pressing specific button combinations. Check the tech sheet inside the unit for service mode entry instructions to clear error codes.

Frequently Asked Questions

•What is the resistance range I should expect to see on the drain pump?

You should expect to see a resistance between 10-20 ohms. Any reading outside of that indicates a faulty pump.

•How do I access the drain pump on my Kenmore dishwasher?

The drain pump is usually located at the bottom of the dishwasher. You'll need to remove the lower access panel, typically using a 1/4-inch nut driver. You may also need to remove a lower spray arm and some internal components to gain full access.

•Where is the control board located, and how can I check the drain pump relay?

The control board is usually located behind the front control panel of the dishwasher. You'll need to remove the outer door panel to access it. Visually inspect the relay for any signs of burning or damage. If possible, use a multimeter to test the relay's continuity according to the wiring diagram. Due to the complexity and risk of damaging the control board, relay replacement is usually not recommended; replace the entire board.

Kenmore Dishwasher Error Code 8-4: Drain Pump Electrical Circuit Fault Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the resistance range I should expect to see on the drain pump?

•How do I access the drain pump on my Kenmore dishwasher?

•Where is the control board located, and how can I check the drain pump relay?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: