Chamberlain · Garage Door Opener Moderate

4-1 — Chamberlain 4-1 — Unexpected Force/RPM Change While Closing

4-1 means an unforeseen change in RPM or DC motor current was detected while the door was traveling DOWN (an obstruction or resistance on closing), so the opener reversed. It is not a low-down-force condition. (Diagnostic meaning corrected against the official Chamberlain Group / LiftMaster Security+ 2.0 chart; flash-code meanings can vary by opener family — confirm for your exact model.)

Keep using it?
Yes, with caution
DIY difficulty
Easy
Verified against
chamberlain.com ↗

How to fix it

  1. Clear the door path and check for obstructions on the track.
  2. Clean and lubricate the rollers and track.
  3. Re-run the force/travel learn after clearing the cause.

Why it happens

Typical signs: Door reverses while closing · Flash code 4-1

  • Obstruction or unexpected force/RPM change while closing Something in the path, or increased resistance (dry rollers, binding track), on the down stroke.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

  • Garage door bottom seal Common replacement
    Amazon →
  • Garage door lubricant Common replacement
    Amazon →

More Chamberlain garage door opener codes

1-1 1-1 — Safety Sensors Obstructed/Misaligned/Disconnected 1-2 1-2 — Safety Sensor Wires Shorted or Reversed 1-3 1-3 — Door control wire issue / lock button stuck 1-4 1-4 — Safety sensors misaligned or obstructed 1-5 1-5 — Motor Drive / No RPM at Start of Movement 1-6 1-6 — Unexpected RPM After Stop at Open Position

All Chamberlain codes → All garage door opener codes →

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: chamberlain.com.