The short version
In plain terms, 3d31 means the control raised a reading the documentation answers by pointing at a technician instead of naming a part. You can take the power away once to see whether it was a one-off latch, and if it returns the answer is a technician. A one-off latch after a supply event, which a single power-down rules out explains more of these than any component failure does.
The documented code reading
Reference| Code | Documented meaning |
|---|---|
| 3d31 | The manufacturer publishes this code for this appliance without an owner-level meaning; it is documented for service diagnosis on the model lines that use it. |
The behaviour that comes with this code
- The cycle stops and the display holds the code — It stays until the power is taken away.
- It returns immediately after a power-down — Which is what separates a real fault from a latch.
- NEAR MISS - the code clears and never comes back — Then it was a latch, and there is nothing to repair.
What triggers this code, most likely first
- A one-off latch from a supply event — Ranked first because it is the only cause an owner can do anything about, and one power-down settles it.
- A connection inside the machine rather than a failed part — Second: connectors and harnesses account for a large share of codes that look like component failures from the outside.
What to check first, second and third
- Note exactly what the machine was doing when it appeared — Which cycle, how far in, and what else was running - all of it shortens the visit.
- Resist the urge to keep restarting — Repeated attempts on an unknown fault add wear and tell you nothing new.
Steps you can take yourself
- Power the machine down at the breaker, then bring it back — If the code clears and stays clear, it was a latch.
About 5 min
- Leave the machine unused if it involves heat or water — An unknown fault on a heating or filling appliance is not one to leave running unattended.
- STOP HERE - do not open the machine — Unplug the appliance or switch off its breaker before any panel comes off; a capacitor can hold a charge after the power is off.
Safety first, and it is not optional
Safety
Unplug the appliance or switch off its breaker before any panel comes off; a capacitor can hold a charge after the power is off. Everything in the procedure above stays outside the cabinet for that reason. Leave the door switch and the other interlocks exactly as they were fitted - they exist to stop the appliance running when it should not.
When to call a technician
Where an owner stops: this is a call rather than a repair: the manufacturer publishes no owner-level meaning for this code, and the diagnosis needs the service documentation for the model line and a meter. And where nobody should wait at all: call immediately, and leave the appliance switched off at the breaker, if there is a burning smell, visible scorching, or a breaker that will not hold.
Codes read alongside this one
The scope of this reading
The reading on this page applies to the model lines for which the manufacturer publishes this code without an owner-level meaning. Two things are deliberately absent: anything that varies by model line, such as part numbers and wiring detail, and anything the manufacturer publishes only to technicians. Where a page exists for your specific family or model, that page takes precedence over this one, and the index linked below points to it.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
