LiftMaster 8160W / 8165W and Chamberlain C2102 / C2405 chain-drive openers (Security+ 2.0, myQ): quick sheet

A command from the wall control, a remote, a keypad or myQ reaches the logic board. On the DC models the motor ramps up and down (soft start/stop); the 8165W uses a 1/2 HP AC motor. The motor turns a drive sprocket on top of the unit, the chain moves the trolley, and the door arm pushes or pulls the door.

Limits are not mechanical screws. A travel module (encoder) reports motor rotation to the logic board, and the open and close positions are taught with the programming (adjustment) button and the UP/DOWN buttons on the motor unit. Force is learned automatically during the first cycles; if the measured effort rises above what was learned, the opener stops and reverses and flashes a 4-x code.

Closing is only allowed when the safety reversing sensors see each other with steady LEDs. Missing, shorted or misaligned sensors block the close and flash the lights (codes 1-1, 1-2, 1-4, 4-6). The wall control talks to the board over a two-wire data line, so a shorted or reversed wire there gives code 1-3.

Radio is Security+ 2.0 (rolling code). Only myQ and Security+ 2.0 accessories pair with these units. Older HomeLink vehicle systems may need a compatibility bridge. Wi-Fi models need one complete open/close cycle after setup or a power outage to relearn.