The E91 error on your Samsung Washer means there is a communication error between the main control board and the inverter control board. This error typically requires inspection of internal electrical connections and circuit boards.

Error code E91
Meaning Communication failure between main control board and inverter board
Severity High — Washer will not operate until resolved
Time to fix 20–60 minutes
Tools needed Screwdriver, multimeter, flashlight

What the E91 error means

The E91 error code indicates a breakdown in communication between the main control board (PCB) and the inverter control board in your Samsung washer. These two critical components must constantly exchange signals to regulate motor speed and washing functions. When this communication fails due to loose connections, damaged wiring, or faulty boards, the washer displays E91 and stops operating to prevent further damage.

Common causes

  • Loose or disconnected wire harness between control boards
  • Corroded or damaged connectors on the main control board or inverter board
  • Failed inverter control board (VFD board)
  • Defective main control board (PCB assembly)
  • Damaged wiring harness due to vibration or wear
  • Power surge or electrical interference affecting board communication

How to fix the E91 error

  1. Power cycle the washer — Unplug the washer from the electrical outlet or turn off the circuit breaker for 5 minutes. This resets both control boards and may clear temporary communication glitches. Restore power and run a test cycle to see if the error returns.
  2. Inspect wire harness connections — Unplug the washer and remove the rear access panel. Locate the wire harness connecting the main control board (usually at the top front) to the inverter board (typically at the bottom). Check that all connectors are firmly seated and not loose, corroded, or damaged. Disconnect and reconnect each connector to ensure proper contact.
  3. Check for visible damage — Examine the wiring harness for signs of fraying, melting, or damage from rubbing against moving parts. Inspect both control boards for burn marks, swollen capacitors, or other visible damage. If you find damaged wires, they must be repaired or replaced. Use a flashlight to thoroughly inspect all connections.
  4. Test with a multimeter — If connections appear intact, use a multimeter to test continuity through the wire harness. With the washer unplugged, disconnect the harness at both ends and test each wire for proper continuity. Any broken wires indicate the harness needs replacement.
  5. Replace the inverter control board — If all connections are good but the error persists, the inverter board is the most common failure point. Order the correct replacement board using your washer’s model number. Disconnect all wires (take photos first), remove mounting screws, install the new board, and reconnect all harnesses.
  6. Replace the main control board — If replacing the inverter board doesn’t resolve the issue, the main control board may be faulty. This is less common but possible. Follow the same procedure: document connections with photos, disconnect all wires, replace the board, and carefully reconnect everything. Consider professional service if you’re uncomfortable with this repair.

FAQ

Can I continue using my Samsung washer with the E91 error?
No, you cannot use the washer when the E91 error appears. The washer will not start or complete cycles because the main control board cannot communicate with the inverter board to control the motor. Attempting to force operation may cause additional damage to electrical components.

How much does it cost to fix an E91 error on a Samsung washer?
If you repair it yourself, a replacement inverter board costs $80–$150, while a main control board costs $100–$200. Professional repair typically ranges from $200–$400 including parts and labor. The wire harness, if needed, costs $30–$60. Always verify your exact model number before ordering parts.

Is the E91 error covered under Samsung warranty?
If your Samsung washer is still within the manufacturer’s warranty period (typically 1 year for parts and labor, 3–10 years for specific components), the E91 error repair may be covered. Check your purchase documentation and contact Samsung customer service at 1-800-726-7864 to verify coverage. Control board failures are often covered under extended warranties.