I had never heard of this despite owning the same Pacifica since 2018. So did some golfing. Shoot, googling, though I did play 18 yesterday. The suit is Moran et. al. vs. FCA US LLC. The class action resulted in extending the warranty for the crank position sensor (CPS) from 3/36k to the 5/60k power gain warranty, and/or vehicle repurchase assistance. Don’t find any information on the number of vehicles that had this problem or were bought back. Anecdotally I don’t recall any stalling complaints posted here for ages so it doesn’t feel like a chronic problem. There are a few threads about the class action when it came out and some stalling complaints and repairs.
Replacing the CPS is roughly a $300/1 hour of labor job. It’s not that big a deal from a repair perspective. It does appear that an updated part number was released at some point. A functioning CPS is, however, necessary for the engine to run, as it feeds necessary data to the engine computer. All cars have a CPS, it’s a basic component of a modern engine.
Anecdotally, my 2018 has never once stalled in the 8 years / 90k miles I’ve owned it. No engine repairs of any kind, just scheduled maintenance.
I‘ve had a good ownership experience so have survivorship bias, but wouldn’t let this concern steer me away from a Pacifica if it otherwise met the need.