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I got a 2010 Chevy Silverado 1500 lt 4.8 it will readily at lowest temp on dash and say engine hot ac turned off but I reset the codes by disconnecting battery then reconnect and it’s gone for a day or two and comes back what could it be that is making it pop up note that when I drive and warm it up and it stills reads minimum I reset the battery and it reads 210 instead of cold I have a block heater and coolant is topped up on cold