I bought my 2018 V60 about two months ago and I love it. When I bought it the Auto off/start was not working regardless of what position the lock-out button on the center console was in. I never looked into it very deeply because I didn't care for it anyway. The other day at the tail end of a 100 mile trip it just started working! as an electronics service tech I'm looking at what was the last thing i did before it started working. There were two things. I reset the trip computer and turned of the A/C. It's probably not the A/C because it continues to work with the A/C on. I'm not happy it started working because I have to disable it on every trip. Wondering if anyone has any ideas.

 

The stop/start function started working because the stop/start battery was recharged to a sufficient level after your long drive. When the stop/start battery is somewhat low, and in other conditions (such as very cold weather), the stop/start function will not work. Once/if you ever replace the stop/start battery with a new one, your car's stop/start function will resume. BTW, your car can run fine w/o a charged stop/start battery.