Miele Washer Error Code F4264

Error code F4264 on a Miele washer indicates an EFU fault overrun, specifically a communication fault between the EFU 235 (electronic frequency converter unit) and the ELP 235 (electronic power module). The EFU 235 controls the variable frequency drive for the motor, regulating drum speed and spin performance. The ELP 235 serves as the power electronics board that delivers the high-voltage drive signal to the motor. These two modules must exchange continuous, synchronized data during operation, and when that communication exceeds its timing tolerance or fails to complete within the expected window, the machine logs this overrun fault and halts the cycle.

Overrun faults of this type typically point to one of three root causes: corrupted or interrupted data transmission on the bus line between the two modules, a hardware failure within one of the two boards causing it to respond outside its timing window, or electrical interference disrupting the signal integrity between the units. Wiring harness damage, loose connector pins, or corrosion at the interconnect points between the EFU 235 and ELP 235 are frequent physical contributors. Because this fault is logged as a communication timing error rather than a simple open or short circuit, intermittent connection issues can trigger it even when the wiring appears intact under static inspection.

Diagnosing this fault requires inspecting the wiring and connectors between the EFU 235 and ELP 235 for damage, corrosion, or loose seating. If the harness and connectors are sound, the fault may reside within one of the two electronic modules themselves. Board-level repair is generally not practical in the field, so replacement of the faulty module is the standard corrective action. A qualified technician with access to Miele diagnostic software can often identify which of the two modules is generating the fault before committing to a part replacement.