The E51 error on your Frigidaire washing machine means the motor control unit (MCU) has detected a relay problem on the main control board. Most owners can clear it by power-cycling the machine, but a repeat error usually points to a wiring or board fault that needs closer inspection.

Error code E51
Meaning Motor control unit (MCU) relay error — the control board can’t confirm the drive motor relay is switching correctly
Severity Medium — the washer usually won’t spin or drain properly until this is fixed
Time to fix 15–45 minutes
Tools needed Multimeter, Phillips screwdriver, work light

What the E51 error means

Frigidaire front-load and some top-load washers use a motor control unit to manage the drive motor’s speed and direction during wash, spin, and drain cycles. The E51 code appears when the main control board sends a signal to the MCU relay but doesn’t get the expected confirmation back, so it assumes the relay has failed or the connection has been broken.

This isn’t always a dead board — loose wiring, a tripped connector, or a temporary power glitch can trigger the same code as a genuine relay failure.

Common causes

  • Loose or corroded wiring harness connector between the main control board and the motor control unit
  • Failed relay on the motor control board itself
  • A power surge or brief outage that confused the control board’s logic
  • Damaged or pinched wiring near the drive motor caused by vibration over time
  • Faulty main control board that can’t properly read relay feedback
  • Water or moisture intrusion around the control board area

How to fix the E51 error

  1. Power cycle the washer: Unplug the machine for 60 seconds, or switch off the breaker, then restart it. This clears many temporary relay communication faults without any parts needed.
  2. Check the door and drain first: Make sure the door is fully latched and the drain hose isn’t kinked, since some E51 triggers are secondary to a stuck cycle rather than a true relay fault.
  3. Inspect the wiring harness: Unplug the washer, remove the rear or control panel, and check the connectors running from the main control board to the motor control unit for looseness, corrosion, or burn marks.
  4. Test the motor control unit relay: With power off, use a multimeter to check continuity across the relay contacts on the MCU board. No continuity when it should be closed points to a bad relay.
  5. Reseat all connectors: Firmly disconnect and reconnect each plug between the main board and MCU, since a partially seated connector is a common and cheap-to-fix cause.
  6. Replace the motor control unit or main board: If testing confirms a dead relay or the board fails to reset after a clean power cycle, the MCU or main control board will need replacing — this is best done by a technician if you’re not comfortable working with boards.

FAQ

Can I keep using the washer if E51 clears after a restart?
Yes, for now. If the code doesn’t come back within a few wash cycles, it was likely a one-off glitch. If it returns, treat it as a wiring or board issue that needs checking.

Is E51 dangerous or does it damage the washer?
No, it’s a protective code that stops the motor from running with an unconfirmed relay state. It prevents damage rather than causes it, but leaving it unresolved means the washer won’t complete cycles.

Do I need a technician for this repair?
Not always. Power cycling and checking connectors is safe for most homeowners. Testing or replacing the motor control unit board involves handling live electrical components, so call a technician if you’re unsure.