air condition stop working it control button blinks for 5 seconds then shut down on 2006 Mercedes-Benz E350

i took it to repair shop to check freon it will only take 12oz of freon and the clutch stays on but it do not click it runs all the time

Asked by for the 2006 Mercedes-Benz E350
1 answer
have codes scanned its trying to tell you there is a problem