Possible causes – Faulty Engine Control Module (ECM)– ECM harness is open or shorted– ECM circuit poor electrical connection– Shorted sensor on 5 volt circuit Tech description There is a factory service bulletin for the P0642 code for the following models: 2005-2007 Audi A32005-2007 Audi A42007 Audi A4 Cabriolet2008 Audi TTAudi Factory Service Bulletin OBDII…