Hi! Did you ever get this resolved? Having the exact same issue. For years the VSC lights and CEL would go on after a hard rain for a day (or less), but they've been on since last week.. Today my "P" light began staying lit while in drive/reverse/etc.. Getting the codes read this weekend but any insight would be appreciated! I got my sunroof drain lines cleared a few months ago so I don't believe it's water leaking in? Ugh.
Leaking water around the sunroof seal was causing my issue. Cleared the drains and still was experiencing it. Remove the black plastic sunroof trim pieces and you'll see some drips of water if the seal is leaking. Replaced it and no issues since!