AEG Washer Error Code E66

E66 indicates a tachogenerator interruption, meaning the washer's control board received no speed signal from the motor-mounted tachogenerator for 15 minutes. The tachogenerator is responsible for reporting drum rotation speed to the control board. Without this signal, the washer cannot regulate the cycle and shuts down to prevent damage. The fault points to the tachogenerator, its wiring, or related connections.

No, you should not attempt to run the washer with E66 active. The machine has stopped the cycle because it cannot monitor motor speed, and continuing to operate it in this condition could cause further damage to the motor or other components. Stop use until the fault is diagnosed and repaired.

A reset may temporarily clear the displayed error code, but it will not resolve the underlying fault. If the tachogenerator or its wiring is faulty, the signal interruption will persist and E66 will return once the machine attempts to run. A proper repair to the tachogenerator or wiring is required to permanently clear the fault.

A knowledgeable DIYer can start by checking the wiring harness and connectors between the tachogenerator and the control board for loose or damaged terminals, which requires no parts. If the wiring is intact, replacing the tachogenerator is the next step, and this involves accessing the motor assembly inside the machine. Comfort with disassembling the washer and working near electrical components is necessary, so professional service is recommended if you are not confident in those tasks.

If only a wiring repair or connector reseating is needed, costs are typically low, mainly covering a technician's diagnostic time. Replacing the tachogenerator itself generally falls in the range of $80 to $200 including parts and labor, depending on your location and the service provider. If the underlying motor is also damaged, repair costs can be considerably higher, ranging from $200 to $400 or more.