Hi there. The code U0100 (https://www.obd-codes.com/u0100) means that the ECM (computer) has lost communication. Check the battery and the battery cables and make sure that they are in good condition. Check the ground wires to the chassis and to the...
P0604 is an internal memory error in the ECM. It will need to be replaced. It may be possible to get a pre-programmed ECM for you to put in, but this would be a question to pose to your local...
