You should be able to find coverage details in the contract you signed when purchasing the CPO. For my recent purchase, the CPO extended the 4-year factory warranty by 12 months. E.g.,
Note all the things that are NOT covered such as batteries, brakes, clutch, tires, hoses/belts, paint, lights, etc. I took my CPO 340 in a couple weeks after purchasing to address an
apparently common squeaking from the door jams. Even though it's listed in the items not covered, they fixed it due to a creaking door SIB. I wasn't as lucky ~9 years ago when I took my CPO 535 in to the dealer for weird electrical issues. It ended it being a bad battery and they tried charging a large diagnostic fee + battery replacement. I pushed back and reduced the diagnostic fee by half. Still wasn't too pleased but lesson learned!