Chevy Somic 2014. Can a bad thermostat affect air conditioning? I changed the thermostat in my Chevy Sonic at the end of January in the middle of winter. But, the repair shop who did it didn't put the right thermostat. We were told that if it's not a GM part, the car's computer will read something wrong and send a Check engine code.         

Summer is here now, we tried our AC today and it's blowing hot air.           

Is it related?