Questions and Answers
Secret Codes & Shade Tree Mechanics
Q. I would like your comments on the code readers that are now available for various makes of cars. Being a "shade tree mechanic", I sometimes feel lost under the hood of the newer cars, but do enjoy working on my own car. Thanks for your time.
A. For the rest of our readers; Code Readers are a simple device that, when plugged into the diagnostic connector of the car's computer, cause the computer to flash its Malfunction Indicator Lamp (MIL). The MIL is trade talk for the Service Engine Soon, Check Engine, Power Loss, ECU etc.. light that is seen on the dash of most all cars made today. Once the MIL starts flashing, one counts the number and sequence of the flashes. This provides a numerical count of one, two or three digits which are referred to as fault codes. These codes are used as a guide to identify computer related problems.
Here's the problem: once you have this information what do you do with it? The most common and dangerously seen approach is replacing a part, based on the code alone. A great example is the oxygen sensor code. There are several factors other than a faulty oxygen sensor that will cause the computer to display a code for an O2 sensor problem. But a new O2 sensor will not be the fix.
The only way to know for sure is to follow a diagnostic path that is found in factory type repair manuals. Once you buy the manual you will quickly find that there are special tools required to perform proper diagnostics. So a code reader is a neat gadget, but will it be of any help to you? Not unless you're ready to buy more tools and do a lot of reading. Don't lose heart; your car still needs maintenance that is no different than that of vehicles 20 years ago. There's still plenty to enjoy.
