Yes, that's a good idea too!

A buddy of mine had a problem with a later model diesel F250 and the code given nailed the issue dead-on. I guess I was just being lazy. I've got a code reference manual laying around somewhere (I think it's at the bottom of a stack of 'Hustler' magazines) that I should dig out.

I also found on-line a guide for using a multimetre to verifying the serviceability of the TFI modules. I spent about a hundred and twenty bucks for a new module and a coil that the truck didn't need...