check engine light / no a/c

first ive had a few problems with this car, sunroof isnt workin properly, windows are sometimes erratic, power seats arent tilting up and down in the front, and now the a/c went out and a check engine light came on, i went to auto zone to have the code checked and the scan tool said there was an error and wouldnt connect to my ecm.. does anyone have any ideas as to what could be wrong with my car, if i dont figure out anything soon im just gonna tell the dealer to take it back and give me something different

Did you get a Carfax report on this car before you bought it? Seems like a lot of electrical problems for a clean car. Was it ever in water or wrecked?

How does your battery look. Many X-type batteries crack near the negative cable and corrode the cable. This causes all sorts of problems.

ive never heard of the battery doin that, but ill definately check that, and i didnt get a carfax report, i should have, but i didnt think of it when i bought the car, life lesson i guess