Hi I have a 1996 Ram 1500 5.2L the original PCM had crapped out and I had pulled one from a salvage yard from a 98 1500 5.2L and installed it as I read somewhere online that it wouldn't need reprogramming and they didn't have a 96 available.. now the issue(s) I'm having: the obd port is not communicating with any tool but the 12v pin is supplying power. May or may not be related issues: rpm/tach gauge not working, "O/D off" light is on constantly.. I don't have a CEL on but the bulb might be bad I will have to check it but I will like some idea of what to check/do. Thanks in advance

 

98 PCM won't work on your truck. Too much changed. You need a 96 or 97 PCM. I don't think you will need to flash the VIN on those....... but, not 100% on that.