I have an '03 and my check engine light came on. I got the code P0380 and have been searching for answers and am getting confused why it matters about California of Federal emissions

 

If you're still there, California trucks have a controller that controls each glow plug individually while the rest of the trucks have a controller that controls each bank together. Supposedly the California controllers are more robust but are harder on glow plugs; the rest are easier on glow plugs but eat controllers.

 

Thank you. Is the controller the same thing as the relay? I am hoping its the relay cause that would be easier to replace, but is there just one or 8?