What did you replace? The cylinder head? How much did it cost? Any help from Mazda? At 53k they should offer some assistance. Why would you sell the car after having it fixed?
You can go in and reset the light. I don't go by the light. Track it myself. They probably set it for
3,000 miles so it's giving you advance warning. You're good for 5,000, maybe even 7,500 depending on how you drive. Just make sure it gets changed once a year at least.
2016 with the original battery - must be a record.
99% sure your problems are the battery.
Go buy one, make sure you can return if it doesn't fix the problem.
And yes, bad battery can cause all kinds of dash problems.
Replacing my 19, keeping my 16. Dealer looked like they had a decent supply on the lot.
A lot more than the last time I was there (about 5 months ago).
I talked to a sales guy, got some literature, no sales pressure.
Powertrain warranty runs out in 4 months.
Sounds like a bad battery.
Did the car start OK after you removed the battery for 1 hour?
What year is vehicle, how old is battery, etc.
It's helps diagnosis if this info is offered.
Search this forum. Posts about ghost infotainment or something similar.
I think there was a TSB for the problem but probably won't help you since you're out of warranty.