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Error code reference

AEG Washer Error Code E91

Reading error of program selector

AEG codesAEG washer codes

Reading error of program selector - incorrect configuration data.

First step from the service manual

Replace electronics.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What E91 means on a AEG washer

Error code E91 on an AEG washer indicates a reading error from the program selector, specifically tied to incorrect or unrecognizable configuration data. The main control board is responsible for continuously communicating with the program selector (the rotary dial or selector switch assembly) to determine which wash cycle has been chosen. When the control board cannot correctly interpret the data being sent from the selector, or when the configuration data stored on the board does not match the expected parameters for that selector input, the E91 fault is triggered.

The root cause is typically an internal mismatch or failure within the electronic control system. This can occur due to corrupted firmware or configuration data on the main control board, a faulty program selector that is transmitting incorrect signals, or a communication breakdown between the two components. In some cases, a loose or damaged wiring harness connecting the selector to the control board can cause intermittent or corrupted signal transmission, producing this fault.

Because the error specifically points to configuration data being incorrect, a simple power reset rarely resolves E91 on a permanent basis. The diagnostic approach centers on replacing the electronics, as the control board is the component responsible for storing and interpreting the configuration data. In some situations, the program selector assembly itself may be the failed component generating the bad data, so both parts should be considered during diagnosis.

Source: manufacturer service documentation.

Common causes of E91

  1. 01

    Faulty main control board

    Part replacement

    The control board may contain corrupted configuration data or a hardware failure that prevents it from correctly reading selector input signals. This is the primary suspect and the first component recommended for replacement.

  2. 02

    Defective program selector assembly

    Part replacement

    The rotary program selector can fail internally, sending incorrect or garbled data signals to the control board. If the board tests correctly, the selector assembly itself should be inspected and replaced.

  3. 03

    Loose or damaged wiring harness

    Wiring / connection

    A wiring harness that connects the program selector to the control board may have a loose connector, broken pin, or damaged wire causing intermittent or corrupted communication. Inspect all connectors between the selector and board for secure seating and visible damage.

  4. 04

    Firmware or configuration data mismatch

    Part replacement

    If a control board was replaced previously with an incompatible unit, the stored configuration data may not match the selector assembly installed in the machine. Confirming part compatibility between the board and selector is an important diagnostic step.

See the test procedure for each cause

Frequently asked questions about E91

What does E91 mean on a AEG washer?
E91 indicates a reading error from the program selector caused by incorrect configuration data. The main control board is unable to correctly interpret the signals coming from the selector dial. This prevents the washer from identifying which cycle has been chosen, so the machine halts operation and displays the fault code.
Can I fix E91 myself, or do I need a technician?
Resolving E91 typically requires replacing electronic components, which is a moderately advanced repair. A knowledgeable DIYer comfortable with appliance disassembly and component swapping may be able to replace the control board or program selector. However, correctly diagnosing which component is at fault can be difficult without experience, so a qualified technician is recommended if you are unsure.
Will resetting my AEG washer clear the E91 error?
A power reset is unlikely to permanently resolve E91 because the fault is tied to incorrect configuration data or a hardware failure in the electronics. The error may temporarily clear after a reset, but it will return if the underlying component fault is not addressed. Replacement of the faulty electronics is the correct repair path.
Is it safe to use my AEG washer while E91 is displayed?
When E91 is active, the washer cannot reliably determine which program has been selected, so running a cycle is not advisable. The machine may not operate as expected, and continuing to use it before the fault is resolved could complicate diagnosis. It is best to leave the washer unplugged until the repair is completed.
How much does it cost to repair an AEG washer E91 error?
Repair costs depend on which component has failed. A replacement main control board typically ranges from $80 to $250 for the part alone, while a program selector assembly generally costs between $20 and $80. Adding professional labor, total repair costs can range from $150 to $400 or more depending on your location and the specific parts required.

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