2006 1 ton dually was told the ecm was no good that is why no air conditioning can that be true

 

Its possible, but not probable.

 

Well it is probable and possible. I just had mine replaced(under warranty) because the tech center said that was what was causing the compressor clutch not to enage. Have had cold air since. Been 4 weeks now. They even paid for a rental the 2 weeks they had it.