## How to Fix Electrolux Error E91 (Communication Error)
If your Electrolux washing machine is displaying the error code **E91**, it can be frustrating, especially if the machine appears to be completely unresponsive. This guide will help you understand what this error means and provide a clear, step-by-step process for troubleshooting and resolving the issue.
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### 1. Explanation: What is Error E91?
The **E91** error code is a general **Communication Error**.
In simple terms, your washing machine’s main computer (the main control board or MCU) is unable to communicate properly with the front display and button panel (the User Interface Board or UI).
This issue is almost always electrical or component-related. The likely culprits are:
* A loose wire harness connecting the two boards.
* A failed **User Interface Board** (the most common cause).
* A failure on the Main Control Board (less common).
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### 2. Step-by-Step Fix: How to Diagnose and Troubleshoot E91
Before calling a professional or ordering parts, follow these steps in order to try and reset the system and isolate the problem.
#### Step 1: Perform a Hard Reset (The Power Cycle)
Electronic communication errors are often temporary glitches that can be cleared by fully draining the machine of power.
1. **Unplug the Machine:** Locate the power cord and unplug the washer completely from the wall socket.
2. **Wait:** Wait a minimum of **5 to 10 minutes**. This ensures that any residual electrical charge in the capacitors and circuit boards is fully discharged.
3. **Plug Back In:** Plug the machine back into the wall socket.
4. **Test:** Turn the washer on and try to start a cycle.
If the E91 error persists, proceed to the next step.
#### Step 2: Check the Wire Harness Connection
The most common point of failure, after the UI board itself, is the physical connection between the two main components.
***Safety Warning:** Always unplug the machine before removing panels or accessing internal components.*
1. **Locate the Boards:** The User Interface Board is located directly behind the front control panel/display. The Main Control Board is often located elsewhere, sometimes at the bottom or rear of the machine, or occasionally behind the dispenser drawer.
2. **Access the Control Panel:** On most Electrolux models, you will need to remove the top lid (usually held by two or three screws at the back) to access the UI board components from above.
3. **Inspect the Connection:** Identify the ribbon cable or wire harness that runs from the Main Control Board to the back of the User Interface Board.
4. **Reseat the Connector:** Gently but firmly unplug and then re-plug this wire harness connector at both ends (if accessible). Look for signs of corrosion, burned plastic, or wires that have slipped out of the plastic connector housing.
If the connection looks secure and clean, but the error remains, the hardware itself is likely faulty.
#### Step 3: Identify the Failing Component
Since the E91 error specifically indicates a failure to communicate, and the wiring has been checked, the fault lies with one of the two main circuit boards. The User Interface (UI) board is significantly more likely to fail than the Main Control Board (MCU) in this scenario.
**Why the UI Board is the Culprit:**
The UI board often handles complex signal processing from user input (buttons) and display output. It is more susceptible to small power spikes, humidity, or general wear and tear from constant use.
**Recommended Action:**
The most efficient troubleshooting step at this point is to replace the **User Interface Board**. If the communication error persists after replacing the UI board, the problem then must reside in the Main Control Board (MCU).
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### 3. Replacement Part Information
To ensure the fastest repair, have your washing machine’s **Model Number** handy (usually found on a sticker inside the door rim). This ensures you order the exact compatible User Interface Board.
Check the price for a replacement User Interface Board here: https://www.amazon.com/s?k=Electrolux+User Interface Board&tag=trivian-20