Just a little heads up for you 3rd Gen owners I know I had the simple error coe list at the top of the page. I'm currently working on the explained version of the error codes for the site you might want to take a look over here. It's incomplete but about half of them are there now. http://articles.mopar1973man.com/3rd-generation-dodge-cummins/60-obdii-error-codes Enjoy...

Very close to completion of the error code listing but most of the engine codes are present I'm only short a few of the transmission codes.