Silly. When I owned my own repair shop, I had the arrogance to think that inexpensive hand held automotive code readers were a hoax. It is easy to get cocky after owning a very reputable and competent repair shop for 25 years and having an array of the most technologically advanced and expensive automotive scanner-code readers at my disposal. Since I sold my shop a little over 3 years ago, it is evident why some auto enthusiasts or home repair artists absolutely need at least a code reader to effectively repair a modern car.

Without at least a code reader you’re just spitting in the wind. Recently I answered a question that was asked by one of our subscriber/readers at GotEngines.com Blog about a problem with his Caravan. I assume someone had scanned it with some sort of reputable scan tool and told him it was a TCC code P0740. Should he have had the desire, simple tools and skills to replace the bad part (VSS)(vehicle speed sensor) than it would have saved him a bunch of doe having a small hand held code reader, especially in the long run(in his case). Most likely, since I never actually diagnosed the car myself, it could have been that simple.

For the wise ‘back yard mechanic’ it is important to have an affordable scan tool in order to see if you find a code/ problem that may suggest something external from the engine caused the failure. Code readers come with code books, therefore allowing you to see what the code means. A lot of times you can fix it yourself. The real reason it saves money for the handy homeowner is there are no wasted parts. You do not need to use the ‘buy parts ’till it works‘ method anymore. That is certainly worth the $45 to $100 a hand held home scan tool costs. Especially in frustration!

External sources could be the automobiles (ECM) electronic control module. This is somewhat hypothetical, but, what if the ECM sent a signal to the fuel injectors so the engine ran super lean all the time, which would make the engine run very nice. At the same time it would run very hot internally. Possibly causing an aluminum piston(all automotive pistons are aluminum) to melt a hole in it from running to lean. This is highly unlikely to happen, but it is possible.

Anyway, you need an effective way to clear the codes after replacement of engine or the repair has been made. In many cases just unhooking the battery for 15 minutes will clear codes, the best way is to clear the codes with a code reader tool and unhook the battery.

It is a good idea to road test the car after the repair and check it for codes again. Insuring the problem is gone. Tune in to our next post on March 11th at GotEngines.con Blog for the rest of the hand held and professional discussion….