Modern cars are technical marvels that use multiple complex computer systems and modules to run everything from your engine to your seat heater. When something breaks many people tend to think that diagnosing a car is simple, quick, and as easy as hooking up a code scanner. Due to the popularity of YouTube Auto repair videos videos, the general public has the misconception that the car is capable of telling you exactly what is wrong. Then all the mechanic has to do is change the part and reset the computer. Rarely is the solution that simple.
Why diagnosing a car can get complicated
Check engine lights are triggered by a component in your car that is out of tolerance which makes the computer turn the service engine soon light on your dash. Generic scanners can interpret codes simply as “P0300” Multiple Cylinder Misfire, which can help narrow down to where the component is failing. A technician will know that the code is ignition related, so what is next? Does the technician change everything that is ignition system related? How does a technician know exactly what part of the ignition system is causing the misfires? Replacing everything related to the ignition system can cost thousands of dollars in a modern car. And what if after changing everything the light comes back on for “Multiple Cylinder Misfires”?
A reputable and experienced mechanic shop will then proceed to testing each individual ignition component to see which component exactly is failing. This step is very important because a Multiple Cylinder Misfire code can be set by something completely unrelated to the ignition system. It could be easily caused by a bad air meter also known as a Mass Air Flow sensor. It can also be caused by a bad crank sensor, inadequate fuel pressure, or simply a broken wire somewhere in the wiring harness. Nine out of ten times having a check engine light code read will not tell you what repair needs to be performed.
Why a good mechanic shop will save you money
An experienced technician from a reputable mechanic shop will pull codes and use their knowledge as well as their experience to methodically troubleshoot the problem. This might require checking voltages, continuity, or fuel pressure. Checking these components also requires thousands of dollars in specialized equipment, knowledge, and time. A bad mechanic shop will pull codes and simply start changing parts on their customer’s dime whether it fixes the problem or not, but will happily stick you with a large bill. This is why diagnostics from a reputable shop take time and will save you money in the long run.