I am very happy to see that times of “free diagnostics” are slowly but surely going away.

Few years ago when I was posting on the same issue on another website it was super easy to find a header picture for illustration. Today I struggled to do the same, wow! 🙂

Instead I found perfect illustration of true value of “free diagnostics” on the picture above

“Free Diagnostics” was one of the worst marketing ideas in this business.It derived from false preposition that computer can replace mechanic’s brains. Not sure about every mechanic out there, some of them are not very bright alternatively smart not quite cut for the job, but so far there is no computer that would go near the brain power of good diagnostic technician. I have a high hopes regarding artificial intelligence but it is not out there just yet. Actually, asking AI to fix a car would be not bad of a test to find if that artificial intelligence is, indeed, intelligent…

When on-board self-diagnostic systems were deployed first it was so unusual and revolutionary that it made an impression as if computer, indeed, can tell what part went bad. This idea then plagued industry for the next couple of decades.

Yes, there is a good chance if you have Check Engine light on and some code like P0228 Throttle Position Sensor C Circuit High Input  shows up on a scan tool screen – you can replace throttle position sensor, clear code and get problem fixed. The problem is that it is not always the case.

There is almost always more than one possible cause to have certain code set by self-diagnostic system. The better you get as diagnostic technician the more possible reasons you can imagine that would cause certain code or symptom. It is a bad technician who can only think about one cause for every code and rush into replacing some part “that always goes bad on them”. Good technician would know all or most of the possible reasons and will do diagnostics as a process of elimination of all possible causes except one – the right one.

It took years for shop managers to realize that technicians does not have magic crystal ball or not-less-magic computer or some psychic powers, extrasensory perception or clairvoyance abilities to know right away every time what part exactly failed in customer’s car, what has caused that and what needs to be done. Process of figuring out correct answers (as opposed to more or less educated guesses) to those questions called diagnostics. It takes time and someone has to pay for that time or eventually there would be only rare volunteers willing to do this work.

If business is desperate to attract customers and doing something for free is the only marketing idea it can come up with than it should call this service “free scan for fault codes”. Because that’s what it is, actual diagnostics is a completely different animal.