1) What are possible (known) causes for the dimmed display on the radio unit? Unknown. Either not gettting proper current to the right palces or internal problem (as most have been) 2) What is diagnostic procedure (how is it done)? For the tech as the dealer to check for power & continuity. 3) What are possible (known) results of the diagnostic? Not correct continuity, not correct power or bad unit. 4) How is the cause of the problem determined based on the results of the diagnostic (how are diagnostic results mapped into possible causes of the problem)? They check for power & continuity in a specified order & nothing is wrong there, then the unit is deemed as "bad" & sent back to the engineers. 5) What is action required for fixing the probem for each possible cause of the problem? Replacing the unit.
