A little logic based in knowledge and a couple simple instruments covers a lot of territory with this sysetm. Parts used with logic can be efficient testing as long as the customer isn't keeping the parts.

I usually only go to the point of logic testing and basic test confirmation before I hang a part. I own many parts this way but there is a point of deminishing returns to total complete testing with labor as costly as it is. By working only on a couple types of automobile parts replacement testing can be used to great benefit. Once I own a control unit testing of such just became a piece of cake. I usually, when faced with a large diagnostic labor charge to prove a guess (some peoples guesses are better than others - and maybe not a true guess), try to find the unit used. This is particularly in the case of expensive control units. If I am right the customer is miles ahead; less diagnostics and a cheap part. If I am wrong I add to the list of easy to diagnose control units.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician