Frigidaire · Washer Serious

E5B — Low DC bus voltage at motor control

MCU is detecting low DC bus voltage. Usually a power supply or capacitor issue on the motor control board.

Keep using it?
Limited use only
DIY difficulty
Hard
Verified against
frigidaire.com ↗

How to fix it

  1. Measure outlet voltage during cycle start — should hold 115 VAC or better.
  2. Plug washer directly into a known-good 15 A circuit, not a shared one.
  3. Inspect MCU for bulged caps.
  4. Replace MCU if caps are bad.

Why it happens

Typical signs: Won't enter spin · Resets mid-cycle · Display dims when motor tries to run

  • Low household line voltage Brownout or shared circuit dipping below 108 VAC.
  • Failed bulk caps on MCU Dried electrolytics can't hold the DC bus.
  • Bad noise filter or line fuse Reduces voltage reaching the MCU.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

  • Frigidaire motor control board Common replacement
    Amazon →

More Frigidaire washer codes

E10 E10 — Water fill problem E11 E11 — Fill time too long E13 E13 — Water leak or air leak in pressure system E20 E20 — Drain pump won't pump out E21 E21 — Slow drain / water remains in tub E23 E23 — Drain pump relay fault on control board

All Frigidaire codes → All washer codes →

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: frigidaire.com.