Diagnostics?

Question

Why do people think a diagnostic of a vehicle with a running problem is nothing more than "pulling with a scanner" a "code"? Doing diagnostics for over 20 yrs now, just because a code is in the computer doesn't mean that part is bad. So why then does Autozone sell you a part just because it has for example a code for an O2 sensor? Does that mean than you are going to buy a transmission because it sets a trans code? Trained techs do more than pull a code, charge you 80 bucks and put a part in, because most are not the fault of a sensor. If you get your "free" scan from autozone and it doesn't fix your complaint, does autozone stand behind you and let you return a electrical part?

Answer 1

yes , good points both of you , also what a lot of people ( techs and tourists ) forget is that under all the wiring and sensors is an internal combustion engine , how many sensors and computers have been replaced when bent push rods or collapsed compression rings are the true culprit ? i took automotives in school ( while the earth was still cooling ) and saw that the industry was going to be in turmoil for many years until the electronic stuff was sorted out so i kept auto repair as a hobby , my hat is off to you guys that need a degree in computer science as well as knowing how to best beat apart a reluctant ball joint.

Answer 2

People are stupid and think the computer of a vehicle is advanced. Its really not. I get taht a lot at the shop, well my cars running bad, can you hook the computer up to it and tell me whats wrong? it doesn't work like that, you get a code and then you find a diagnosis procedure and follow the procedure eleminating all non possibilties. Getting a missfire code doesn't mean the car is nessicarly misfireing becaue of a fouled plug, there are many possibilties of why, and you have to figure it out why its misfiring, as an example.

The scanner is no more then an electronic wrench, if you don't diagnosis, its no more effective then using a 3/4 inch wrench on a 1/4 fastener, you can turn the wrench all day, but you'll get nowhere. Diagnosis is very important when it come to electrical. Yet people do not understand how hard it can actually be.

Simplest terms, a scanner is a tool, it doesn't tell you whats wrong. it tells you where to look, what system to look at.

I do not agree that autozone and who ever else that offers free scanning should have the right to. They are doing it thinking that everyone knows how to diagnose the problem, and if the most obvious fix, doesn't fix it, then they get mad at mechanics for having poor scanners, and think thier all alike. They arn't. I have a cheap scanner i paid about $300 for (the same one autozone and other parts stores uses). The only thing its good for is clearing codes and turnign the check engine light off. The scanner I have at work as a shop scanner, has cost $13 000 and it top of the line with all the updates up to date and all the packages, domestic, asian and european. This scanner gets into most cars diagnostic senters adn alous you to opperate some moduals, sensors, ect manually, and you have grafing ability so you can look at patterns of failures, and what not, they are two completly different things. but people thing that they are the same. they are far from. I could go into detail about the scanner we have, but no one (aside from technicians) would understand it. think of the scan tool as a PC computer, the scanners garages uses are top of the line running windows xp (my snap-on scanner does, just a basic form, with very different menus) and then put that up to an original "micro computer processor" what will do a better job in todays world?