p1605 code

P0325 Knock sensor, This code you will always get, just make sure its hook up, P0600 and P1605 both of these are related , ECM/TCM communication line, Under the dash along the steering column the harness to ECM and TCM continuity needs to be check

where is the a/t diagnostic communication line that indicates that the transmission is in park? is there an electrical sensor in the transmission that communicates with the starting sensor in the engine to tell the engine to start and how do I repair this p1605 code

The transmission range sensor is what used to be called the neutral safety switch and should be mounted on the transmission, right at the shift linkage. Please let us know if you need anything else to get the problem fixed.