LG · Washing Machine
LG Washing Machine SE Error Code
Motor speed sensor mismatch
What this error means
SE is a Sensor Error on the motor circuit. The hall sensor reported drum speed that did not match what the inverter board commanded—often appearing after repeated LE events or following a power surge.
How SE is detected
When SE appears on a LG washing machine, the control board has confirmed that water did not leave the machine within the programmed drain window. On LG WM3700HWA, LG WM3900HWA, and similar variants, the drain pump runs for a fixed interval—often three to seven minutes on washers and dishwashers—while a pressure switch or turbidity sensor verifies the tub or sump is empty. If water remains, the cycle stops to prevent spin with a full tub or overflow on the next fill.
Most SE calls are resolved without parts: unplug for 15 minutes and retry with a small test load. Restricted drain paths mimic pump failure because the impeller spins against a blocked hose or filter. Document whether the pump hums audibly during the drain step; a humming pump with no water movement points to a clogged filter or kinked hose, while silence may indicate a failed pump motor or loose wiring at the harness.
After clearing blockages, run a short cycle and listen at the drain hose for steady water flow. If SE returns on the next load with a clean filter and straight hose, measure resistance at the pump motor connector per the service manual for your model before ordering a replacement pump assembly.
Common causes
- Failed hall sensor on the stator assembly
- Loose motor harness connector at the inverter board
- Damaged stator wiring from vibration
- Inverter board unable to drive the motor correctly
Step-by-step fixes
- 1Unplug for 15 minutes and retry with a small test load
- 2Ensure the drum spins freely by hand with the door open
- 3Avoid back-to-back heavy cycles that overheat the motor
- 4Note whether SE appears with LE—both together strongly indicate motor circuit service
When to call a technician
SE that persists after reset typically requires hall sensor or stator replacement on LG direct-drive platforms.
Affected models
- LG WM3700HWA
- LG WM3900HWA
- LG WM4000HWA
Prevention & maintenance
- Clean drain filters and hose terminations monthly on high-use washing machines to prevent SE from lint and food debris buildup.
- Record when SE appears in the cycle and whether it clears after a 60-second power reset on your LG washing machine—that detail speeds diagnosis if you call service.
- Keep the model and serial number from the rating plate when ordering parts for SE; LG uses multiple revisions with different harness lengths and board firmware.
- Photograph wiring connector orientation before disconnecting any component while troubleshooting SE; reversed plugs on pumps and valves cause immediate repeat faults.