The 31E error on your Samsung Washer means the main control board has lost communication with another key component, usually the motor control board or sub-PCB. Most cases are fixed by checking wiring connections and power resets before any parts need replacing.

Error code 31E
Meaning Communication failure between the main PCB and motor control board (sub-PCB)
Severity Medium — washer will usually stop mid-cycle and won’t restart until resolved
Time to fix 10–40 minutes
Tools needed Phillips screwdriver, multimeter (optional)

What the 31E error means

Samsung washers use several circuit boards that constantly send signals to each other so the machine can coordinate the motor, water valves, and drum movement. The 31E code appears when the main control board doesn’t receive an expected response from the motor control board, often due to a loose connector, damaged wiring, or a firmware glitch. It’s similar in nature to other communication-based faults, like the errors covered in our Samsung Washer SE Error Code: Causes and Fixes guide, where a board simply stops “hearing” from another part of the system.

Common causes

  • Loose or partially disconnected wiring harness between the main PCB and motor control board
  • A power surge or brief outage that confused the control boards mid-cycle
  • Corroded or damaged connector pins from moisture exposure
  • A faulty motor control board (sub-PCB) that has stopped responding
  • Failing main control board unable to send or receive signals correctly
  • Loose ground wire causing electrical interference between boards

How to fix the 31E error

  1. Power cycle the washer: Unplug the machine for 2–3 minutes, or switch off the breaker, then restart it. This clears many temporary communication faults, much like the reset steps used for the Samsung Washer TE Error Code: Causes and Fixes.
  2. Check the wiring harness: Unplug the washer, remove the back or control panel, and inspect the wiring between the main PCB and motor control board for loose plugs or frayed wires.
  3. Reseat all connectors: Firmly press each connector back into place. A connector that isn’t fully seated is one of the most common causes of this error.
  4. Inspect for corrosion or moisture damage: Look for green or white residue on connector pins, which signals corrosion. Clean gently with a dry cloth or contact cleaner if needed.
  5. Test continuity with a multimeter: If comfortable doing so, check the wiring harness for continuity to rule out an internal wire break.
  6. Replace the faulty board: If the error persists after checking wiring, the motor control board or main PCB may need professional replacement.

FAQ

Can I reset the 31E error myself?
Yes. Unplugging the washer for a few minutes often resolves it if the cause was a temporary communication glitch rather than a hardware fault.

Is the 31E error dangerous to ignore?
It won’t damage your home, but the washer typically won’t complete a cycle until the fault is cleared, so laundry may be left mid-wash with water inside the drum.

Do I need a technician for this error?
Not always. Many 31E errors are resolved by checking and reseating wiring connections. If the error returns immediately after a reset, a technician can test the boards directly.