I know this thread is old, but I would like to toss a log on this fire as to why the modules test bad. When I retired, I got a job at AutoZone to keep from going crazy and killing people.. lol
Anyway, I liked working there because as a kid and up to my adult life, I really enjoyed cars, working on cars, and the auto parts business. I even worked in auto parts as a side job and enjoyed every minute of it..
Back to the issue presented. The reason they test bad is that the TFI module evolved over the years, in the mid 80's, there wasn't much in the way of surface mount components, most of the components were bigger transistors, resistors, capacitors, etc inside those TFI housings. As time progressed, so did the size of electronic components.. They got smaller, and engineers modified the inputs and outputs of the devices to pair well with the original pip, coil, etc..
Surface mount components (SMT for short) sometimes present a different load or simply. interface with the components well, but they won't test well with original type testers or testers made to the "white book" specs ford gave them. Basically the left hand not knowing what the right hand is doing.
So the tools used to test are looking for an original spec module based on original ford specs and since the modules have changed several or more times over the years, the surface mount components will work, but they won't test like original parts.
I hope this helps..
Regards Richy04