Chosen Solution

MacBook Air A1466 Touchpad working in diagnostics but not working in MacOS. What will be the issue? SMC done, OS reinstalled but no change.

Please try starting up in Safe Mode by holding down the Shift key on start up. This will tell us if it is a software issue or possible virus.

Diagnostics only goes so far… Your Touchpad needs replacing. Here’s the guide to get it out MacBook Air 13" Early 2015 Trackpad Replacement and here’s the needed part MacBook Air 13" (Mid 2013-2017) Trackpad