I recently went through package car driver training. I was trained on the DIAD at the center where I work. The center put me on the DIAD 3 session, and mid way through I was informed that I would be using the DIAD 4 on the job. What is the big difference in the boards and the way they function. I know that the DIAD 4 has been updated with the EDD program, and I have seen the print out for it. What I don't know is how to use it, or the difference in functions between the two boards. I start on car training and qualifying in a couple weeks. I wish I knew what I was doing, because driving for the company has been my dream and goal for 5 years now. Here's my opportunity and I don't want to blow it.