Rotor Position Sensor, Hall Sensor, Motor Sensor, RPS Sensor

6501KW2002A, 6501KW2002C, PS4221436, AP5328540, 3921ER1003B, 3921ER1003C

LG, Kenmore, select GE (verify by model)

T1024ADF, T1227AGP, T1309ADFH, T1309ADFH6, T1309ADFN, T1327AGP, T1327AGP5, T1327AGP5, T1335ADF, T1423ADFH5, T1423ADFS5, T1428ADF, T1428ADFH, T1428ADFH5, T1435ADF, WM8000HWA, WM2050CW, WM2055CW, WM2455HW, WM2455CW, WM3050CW, WM3055CW, WM3455HW, WM3455CW, WM3555HW, WM3555CW, WM3700HW, WM3700CW, WM4000CW, WM4050CW, WM4055CW, WM4500CW, WM5000CW, WM5050CW, WM5055CW, WM5500CW, WM8000CW, WM8050CW, WM8100CW, WM9000HW, WM9000CW, WM9050CW, WM9100CW, WM9500CW, WM9600CW, WM9650CW, 41262, 41272, 41282, 41292, 41302, 41312, 41322, 41332, 41342, 41352, 41362, 41372, 41382, 41392, 41402, 41412, 41422, 41432, 41442, 41452

Note: This is a partial list. This rotor position sensor is used in many LG-manufactured front-load washers built between 2010-2024. Verify your specific model number for compatibility before ordering. This is an updated version (B) that replaces the earlier version (A).

Required Tools:

• Phillips screwdriver
• Flathead screwdriver
• 1/4" or 5/16" nut driver
• Needle-nose pliers
• Work gloves
• Flashlight
• Towel (to protect washer surfaces)
• Camera or smartphone (for reference photos)

Step-by-Step Installation:

1. Disconnect Power: Unplug the washer from the electrical outlet or turn off the circuit breaker. Never work on the washer with power connected.
2. Shut Off Water Supply: Turn off both hot and cold water supply valves behind the washer. Turn the valves clockwise until fully closed.
3. Move Washer: Pull the washer away from the wall to provide access to the rear panel. You'll need at least 3 feet of clearance.
4. Remove Rear Panel: Remove screws securing the rear panel (typically 4-8 screws around the perimeter). Lift the rear panel off and set it aside.
5. Locate Motor Assembly: Look at the bottom rear of the washer. You'll see the motor assembly—a cylindrical component with the rotor (drum motor shaft) at its center.
6. Locate Rotor Position Sensor: The rotor position sensor is mounted on the motor assembly near the rotor shaft. It's a small plastic component (approximately 2-3 inches long) with a connector terminal and mounting bracket. Look for a component with a wire harness connector.
7. Take Reference Photos: Before disconnecting anything, take clear photos of the sensor showing its position on the motor, the wire harness connector, and mounting hardware.
8. Disconnect Wire Harness: Locate the wire harness connector on the rotor position sensor. Press the release tab and carefully pull the connector straight off the sensor terminals. Do not pull on the wires themselves, only on the connector housing.
9. Remove Mounting Hardware: The sensor is secured to the motor assembly with mounting screws or clips (typically 1-2 fasteners). Remove all mounting hardware using a Phillips screwdriver or nut driver. Keep these screws—you'll need them for reinstallation.
10. Remove Old Sensor: Once the wire harness and mounting hardware are disconnected, carefully lift the old sensor away from the motor assembly.
11. Inspect Old Sensor: Examine the old sensor for visible damage: cracks in the plastic housing, corrosion on the connector terminals, or moisture inside the housing. This helps confirm the diagnosis and identify the cause of failure.
12. Inspect Motor Assembly: Look at the motor assembly where the sensor was mounted. Check for:Rotor magnet (should be visible on the rotor shaft)Mounting surface (should be clean and undamaged)Connector area (should be clean and dry) If the rotor magnet is missing, damaged, or loose, the new sensor won't work properly.
13. Clean Mounting Area: Wipe down the motor assembly mounting surface where the sensor was located. Remove any dirt, debris, or corrosion. A clean mounting surface ensures proper sensor alignment and operation.
14. Prepare New Sensor: Remove the new rotor position sensor from its packaging. Inspect it for any shipping damage. The sensor housing should be intact with no cracks or damage.
15. Compare Old and New Sensors: Verify the new sensor matches the old sensor:Same overall size and shapeSame connector type and terminal configurationSame mounting bracket designSame part number or compatible version
16. Position New Sensor: Carefully position the new rotor position sensor on the motor assembly, aligning it with the mounting holes. The sensor should be positioned so the Hall effect element is close to the rotor magnet (typically 1-3mm gap).
17. Verify Sensor Alignment: Ensure the sensor is properly aligned with the rotor magnet. The sensor should face the rotor shaft with the magnetic sensing element pointing toward the rotor magnet. Misalignment causes the sensor to fail or provide incorrect signals.
18. Install Mounting Hardware: Secure the sensor with mounting screws or clips. Tighten screws firmly but do not overtighten—excessive force can crack the sensor housing or damage the mounting bracket.
19. Reconnect Wire Harness: Plug the wire harness connector back onto the sensor terminals. Push the connector straight on until you hear or feel a click. Verify the connection is fully seated and locked.
20. Verify Installation: Ensure the sensor is securely mounted, the wire harness is connected, and the sensor is properly aligned with the rotor magnet.
21. Reinstall Rear Panel: Position the rear panel back onto the washer and secure with all mounting screws.
22. Move Washer Back: Push the washer back into position, leaving a small gap from the wall for hose clearance.
23. Restore Water Supply: Turn on both hot and cold water supply valves by turning them counterclockwise until fully open.
24. Restore Power: Plug the washer back into the electrical outlet or turn on the circuit breaker.
25. Test Sensor Operation: Run a NORMAL wash cycle without clothes. Listen and watch for:Washer filling with water normallyDrum beginning to rotate when wash cycle startsDrum rotating smoothly and consistentlyWasher advancing through all cycle phases (wash, rinse, spin)Spin cycle operating normally with drum spinning at high speed
26. Verify Drum Rotation: During the wash cycle, verify the drum rotates smoothly and continuously. The drum should not hesitate, stall, or rotate intermittently.
27. Monitor for Error Codes: Watch the display panel for any error codes. If error codes appear (especially UE, UB, or motor-related codes), the sensor may not be working properly or may be misaligned.
28. Check Spin Cycle: During the spin cycle, listen for the motor running at high speed and feel the washer vibrating slightly (normal vibration). The spin cycle should complete normally without stalling or stopping.
29. Verify Cycle Completion: The washer should complete the entire wash cycle without stopping or displaying error codes. The cycle should end normally with the drum stopped.
30. Full Load Test: Run a complete wash cycle with a normal load of laundry to verify the sensor operates properly under normal conditions without error codes or operational issues.
31. Monitor for 24 Hours: Run 2-3 additional cycles over the next 24 hours and monitor for any issues: error codes, drum not rotating, or cycle stalling.

Verify the rotor magnet is intact and properly positioned. The rotor position sensor relies on a magnet embedded in the rotor shaft to function. If the rotor magnet is missing, loose, or damaged, the sensor cannot detect rotor position and the washer won't operate properly. Before replacing the sensor, visually inspect the rotor shaft for the magnet (typically a small black or silver component). If the magnet is missing or loose, it must be replaced or repositioned before the new sensor will work. Installing a new sensor without a functioning rotor magnet is a waste—the sensor won't work.

Test the sensor with a multimeter before replacing. Before ordering a new sensor, verify it's actually faulty. With power disconnected, access the sensor and disconnect the wire harness. Use a multimeter to test the sensor for continuity—you should read approximately 100-500 ohms depending on the sensor type. An infinite reading (OL) means the sensor element is open (failed) and needs replacement. Also test the wire harness connectors for corrosion or loose connections—a corroded connector can cause the same symptoms as a failed sensor.

Check the wire harness and connector for corrosion. An estimated 30% of "sensor failures" are actually caused by corroded or loose wire harness connectors, not a failed sensor. Before ordering a new sensor, inspect the connector terminals for corrosion, oxidation, or loose connections. Clean corroded terminals with fine sandpaper or a contact cleaner. Tighten any loose connectors. A $5 connector cleaning often fixes the problem without needing a $60 sensor replacement.

Verify the control board is receiving sensor signals. If your new sensor doesn't fix the problem, the issue may be the main control board, not the sensor. The control board receives signals from the rotor position sensor and uses them to control motor operation. A failed relay or damaged circuit on the control board prevents proper motor operation even with a good sensor. Before assuming the new sensor is defective, consult your washer's service manual to test for proper sensor signals at the control board connector.

Sensor alignment is critical for proper operation. The rotor position sensor must be positioned at the correct distance (typically 1-3mm) from the rotor magnet. Too far away and the sensor won't detect the magnet. Too close and the sensor may be damaged by the rotor. Proper alignment ensures reliable sensor operation and prevents premature failure. During installation, verify the sensor is positioned correctly relative to the rotor magnet—consult your service manual for exact spacing specifications.

Replace the sensor connector if it's damaged. If the wire harness connector is corroded, cracked, or damaged, replace it along with the sensor. A damaged connector causes poor electrical contact, which stresses the sensor and causes premature failure. Many appliance parts suppliers sell replacement connectors separately ($5-10). Installing a new sensor with an old, damaged connector causes the new sensor to fail immediately.

Motor control board issues often mimic sensor failure. If your new sensor doesn't solve the problem, the motor control circuit on the main control board may be faulty. The control board sends power to the motor based on signals from the rotor position sensor. A failed relay, damaged transistor, or burned circuit on the control board prevents motor operation even with a good sensor. Before assuming the sensor is defective, have a professional technician test the motor control circuit on the control board.