Check Engine Lights


What does this mean? Possibly nothing; maybe something serious. That in a nutshell is the real problem with Check Engine lights.

First a little background. Originally, Check Engine lights were a great idea. Mechanics and engineers worked together to predict component failures by monitoring voltage surges and erratic readings to provide a warning of a possible breakdown BEFORE it occurred. In the beginning this worked well and false alarms from the lights were rare. Then the engineers got together with the computer guys and the accountants and decided that not only could they monitor virtually every component and sensor on the car, but they could also make tons of money on the deal. So they created a marketplace where there wasn‘t one.

We now have hundreds of situations that can trigger the light, (including software glitches) while we still only have a few that can actually cause a breakdown. Not only that, but through creative use of the emission laws, the owner is required to “fix” the car in order to pass the annual emission inspections in most states. The car manufacturer claims credit for looking out for the consumer as the money rolls in replacing parts that an unreliable computer says are bad.

So how do we tell the difference? The first thing that you need to do when you see the light come on is to look at your gauges to see if they are normal. Assuming they are, next evaluate the drivability of the car. Is the engine still smooth? Is it driving normally? Is the transmission shifting as usual? You be the judge. If you feel something noticeably different get to your mechanic right away. If everything feels normal, continue on your way while staying aware of any changes. When you have an opportunity, make an appointment to have the codes read and evaluated.

Who you have analyze your codes is the most important step of the process. When it comes to Check Engine lights you absolutely need a repair shop that treats the patient and not the laboratory. There are those who will use the code readouts as justification to replace components that are not faulty. Often parts are condemned because of a minor erratic reading or because of the domino effect that occurs when the computer can’t decide what the real culprit is and condemns all in one category.

An honest shop will interpret the codes as POSSIBLE problems and make well thought-out decisions about each component and its likelihood of actually being defective. Most honest shops will print out the codes, clear them and road test to see how many return. Quite often this will lead to one specific component that caused the system to overreact. Sometimes the light doesn’t come back on right away. In this case the shop might ask you to take the car, but bring it back as soon as the light returns so that it can be diagnosed before the domino effect kicks in.

One of the most frustrating parts for a shop is how to bill for the diagnosis. The software is very expensive and must be updated at least annually, and the technician’s time isn’t inexpensive either. That having been said, it surely isn’t fair to be hit with a $100 diagnosis every time the computers codes are read. You could easily spend $500 and still not have an accurate diagnosis. One solution many honest shops use is to have an initial diagnosis fee, usually $50-$100, but subsequent readings for a period of 60-90 days are free. This seems to be the fairest way out of a bad situation that was created by the manufacturer, who has made both the shop and consumer victims of its irresponsible behavior.

One last piece of advice: Recognize that while it is frustrating to deal with a recurring light for you, it is equally frustrating for an honest repair shop that is trying to look out for you. The easiest thing for the shop would be to print the list of supposed defects and give you an estimate for their repair. The honest thing is to work together to solve the problems to only fix what is actually wrong with the car. When it comes to check engine lights, don’t shoot the messenger, but make sure you find one who speaks your language.

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