2006 Pontiac Torrent code p0301 and u0100

Question

So  I brought my car into mechanics yesterday had misfire code which I already knew and vent valve code now I have only misfire code and u0100 code

Answer 1

U0100 Loss communication with ECM

P0301 Misfire number 1 cylinders

The misfire code needs to be taken care of first, These are type "A" codes which can suspend any other code that would appear, Most of your misfire are ignition related rather than a mechanical condition such as low compression dealing with the cylinder valves. The sparkplug wire leading into the number 1 cylinder should be checked and also its ignition coil. When you resolve the misfire code you now a clear indication of what is setting a U0100 code, Because the ECM is reporting codes there a possibility the TCM is the source

​ Faulty ignition wire that allow secondary ignition to seek ground are common cause for a misfire code condition

​ Failing ignition coil can also be the cause for a misfire condition