Why does my garage door keep reversing with a liftmaster error code 4-6?

[jamerober]

My garage door opener started acting up this morning. It opens fine, but when I try to close it, it travels about a foot and then reverses back to the top while the lights flash. The diagnostic arrow is showing a liftmaster error code 4-6. According to some things I've read online, this might be related to a sensor misalignment or a wire short, but my sensors have a solid green and amber light. I’ve checked the tracks for obstructions and everything looks clear. Does this code specifically point to a motor issue or the travel module? I’d like to try and fix it myself before calling a technician.

 

[jameswill8520]

That 4-6 code specifically points to a sensor or wiring issue. Even if the lights look solid, there might be an intermittent short in the white/grey wires. Check the staples along the wall; if one is too tight, it can pinch the wire and cause that reversal mid-travel .

 

[AnnisHayma]

Had this exact thing happen last month. Turns out the sun was hitting the receiving sensor at just the right angle, blinding it. Try swapping the sensors to the opposite sides or building a little "cardboard sunshade" to see if it stops reversing. Cheap fix if that's it!

 

[Olivier]

Honestly, if the sensors are solid, it’s usually the travel module or the logic board acting up. Liftmaster boards are notorious for failing after a power surge. If you’ve checked the wires and they’re clean, you might be looking at a board replacement.

 

[Lugwig]

Check the tension on your garage door springs. If the door is out of balance, the motor thinks it hit an object because of the resistance. Pull the emergency release cord and see if you can lift the door easily by hand. If it’s heavy, the code is just a symptom of a bad spring .

 

[captainghost]

Check the "eyes" for cobwebs or dust. I spent two hours troubleshooting a "short" once only to realize a spider had built a tiny web right over the lens. A quick wipe with a microfiber cloth and I was back in business!

 

[ethanwalker]

If it moves exactly one foot and stops, your travel limits might need to be reset. Hold the black button until the up arrow flashes, set the open position, then do the same for the down position. Sometimes the memory just gets "lost" after a minor glitch.

 

[jimmy]

Don't ignore the 4-6 code it’s specifically for the "Safety Sensors." If you have the wires twisted together at the motor head, make sure they aren't frayed or touching each other. A tiny strand of copper touching the wrong terminal will trigger that error every time .

 

[Lisa]

I’d bet money it’s the wire tucked behind the rail. Those vibrates a lot when the door moves, which causes a loose connection to break contact for a split second. Tighten the wing nuts on the sensors too while you're at it!