Chamberlain · Garage Door Opener Serious

4-3 — Chamberlain 4-3 — Loss of RPM While Closing

4-3 means a loss of power/RPM in the motor while closing (loss of RPM during DOWN travel). It is not an unprogrammed-travel-limits 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?
Limited use only
DIY difficulty
Moderate
Verified against
chamberlain.com ↗

How to fix it

  1. Check for binding by moving the door by hand with the opener released.
  2. Inspect the motor and RPM sensor; service if it persists.

Why it happens

Typical signs: Door stops while closing · Flash code 4-3

  • Loss of motor RPM during down (close) travel The motor lost speed/feedback while closing — binding or a motor/RPM issue.

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 →

Frequently asked questions

What does the 4-3 code mean on a Chamberlain garage door opener?

4-3 means a loss of power/RPM in the motor while closing (loss of RPM during DOWN travel). It is not an unprogrammed-travel-limits 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.)

What causes the 4-3 code on a Chamberlain garage door opener?

Loss of motor RPM during down (close) travel: The motor lost speed/feedback while closing — binding or a motor/RPM issue.

Is it safe to keep using a Chamberlain garage door opener with a 4-3 error?

Limited use only. This is rated a serious-severity fault.

How do I fix 4-3 on a Chamberlain garage door opener?

Check for binding by moving the door by hand with the opener released. Inspect the motor and RPM sensor; service if it persists.

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.