I have a 2019 Outback as well. I just went through some battery dying issues. Took it to the dealership, they said that the Onstar module (after 2-3 years) will start to malfunction and create a parasitic drain.
The only fixes they have (as of a couple weeks ago) was to
a) buy a new module (which are on back order because a number of peeps are having this problem) -- which will eventually break because they haven't reengineered it.
b) disconnect the Onstar module via a circuit (my tweeters are on the same circuit, so I'd lose them)
c) Open up the center console and only disconnect the Onstar module.
I opted for C (which I was charged an hour of labor for).
The tech there said to check back in every few months to see if Subaru puts out a new module that fixes the issue.
Edit: The tech told me the Onstar module was a specific issue with 2019 Outback/Legacy, and that 2018 and back doesn't have that problem and in 2020 they redesigned the whole model, so the newer ones don't have that issue.
The only fixes they have (as of a couple weeks ago) was to a) buy a new module (which are on back order because a number of peeps are having this problem) -- which will eventually break because they haven't reengineered it. b) disconnect the Onstar module via a circuit (my tweeters are on the same circuit, so I'd lose them) c) Open up the center console and only disconnect the Onstar module.
I opted for C (which I was charged an hour of labor for). The tech there said to check back in every few months to see if Subaru puts out a new module that fixes the issue.
Edit: The tech told me the Onstar module was a specific issue with 2019 Outback/Legacy, and that 2018 and back doesn't have that problem and in 2020 they redesigned the whole model, so the newer ones don't have that issue.