Your LiftMaster opener is flashing an odd pattern and won't close. On modern Security+ 2.0 LiftMaster and Chamberlain openers (2011 and newer), diagnostic feedback comes from two arrow LEDs on the motor head — an UP arrow and a DOWN arrow — that flash in a two-part code. Here's every published code and what it means, straight from Chamberlain Group's official diagnostic index.
How to Read the Code
Watch the motor head. You'll see a burst of UP-arrow flashes, a short pause, then a burst of DOWN-arrow flashes. Count both. The pair is the code — "1-1" means one UP flash then one DOWN flash. If your opener is a pre-2011 model with a single yellow LED (older Security+ or Billion Code openers), see the note at the bottom.
1-Series Codes (Safety-Sensor and Wiring)
- 1-1: Safety-sensor beam is obstructed, misaligned, disconnected, or has broken wires. Most common code on any no-close call. Clean both lenses; make sure both sensor brackets face each other and both LEDs stay steady.
- 1-2: Safety-sensor wires are shorted or reversed at the terminals (white/black).
- 1-3: Door control panel wires are shorted — usually a nick in the wall-button cable or a stuck wall button.
- 1-4: Sensors were temporarily obstructed or misaligned for less than 4 seconds during the last cycle.
- 1-5: No motor RPM detected in the first second of movement — motor coupler, motor, or logic-board issue.
- 1-6: Motor RPM detected after the opener was supposed to stop at the open position.
Source: Chamberlain Group — Diagnostic Code 1-1.
2-Series Codes (Logic Board)
2-1 through 2-5: Logic-board component failures. Not user-serviceable — either replace the board or (if the opener is 10+ years old and discontinued) replace the whole unit.
3-Series Codes (Power and Cable)
- 3-2: Power outage detected. The opener needs to re-learn its travel positions (open and close it fully once from the wall button).
- 3-5: Cable Tension Monitor is tripped or not detected — the door's lift cable is loose, broken, or off the drum. Do not run the opener until the cable is fixed.
4-Series Codes (Motor and Travel)
- 4-1 / 4-2: Unexpected motor-RPM or current change during down or up travel — something changed how hard the motor is working. Check for a spring balance issue or a door binding in the track.
- 4-3 / 4-4: Loss of RPM during down or up travel — motor is stalling.
- 4-5: Unrecognized travel module (a hardware ID problem inside the head).
- 4-6: A 1-1 or 1-2 sensor condition was present when a close was commanded — go back and fix the safety-eye issue first.
5-Series Codes
5-5: An unattended open or close command was received (from myQ or a smart-home integration) but the required myQ Work Light or accessory isn't installed to allow unattended operation.
Photo-Eye Sensor Behavior (Because 1-1 Is the #1 Code You'll See)
Two sensors sit near the floor on each side of the door opening. The sending sensor emits an invisible infrared beam continuously when powered. The receiving sensor's LED is steady only when the beam reaches it unobstructed and the brackets are aligned. If the receiver LED is off, flickering, or dim: realign the brackets, wipe both lenses (spider webs and Texas dust are the top culprits), and inspect the low-voltage wire from the sensor up to the motor for cuts, staples, or lawnmower damage.
What About Older Openers?
If your opener is pre-2011 (purple, red/orange, or green LEARN button) it doesn't use the two-arrow code system — it just blinks the courtesy light or LEARN LED in patterns to signal safety-eye or wiring faults. The most common failure is still the same: safety sensors. Fix those first before assuming a deeper problem.
Federal Regulation Note
Photo-eye safety reversal on residential garage door openers is required by U.S. federal regulation — the 1993 CPSC rule (16 CFR Part 1211), which requires opener compliance with the UL 325 standard. Never bypass or disable your safety sensors, even temporarily.