How Much Should A Check Engine Light Repair Cost?

Is the mere thought of what your check engine light repair cost might be, keeping you from having it looked at? It seems that there is a question as to value, and serious concerns about price gouging when it comes to diagnosing check engine light concerns. We get this question a lot in one form or another, so we are goning to give you our feelings on what it should cost to have your engine light concerns diagnosed. To a competent and properly qualified technician, diagnosing a check engine light concern is no more complicated or mysterious than performing a tune up. Don't get me wrong, there are the occasional difficult ones, those jobs that require a clever tech to put the book away and rely on his own experience, and an ability to think outside the box, but for the majority of concerns, general system knowledge and the ability to read and follow written instructions is mostly all that is required. This is not to undermine the skill sets needed for these repairs. I mean a technician must be intimately familiar with EGR systems, evaporative emissions systems, a number of different electronic engine control systems, secondary air injection systems, intake and exhaust systems, electronic throttle control systems, fuel trim theory and operation, many different fuel injection systems, multiple ignition systems and on and on.

Not only must you know what each system does by itself, you must know how all systems work together and share information and responsibilities. And as if that's not enough you must be current on all these systems as they change almost yearly. So when we say competent and properly qualified when figuring for check engine light repair cost, we are taking all these things into consideration but they should definaltely not be taken for granted.

The biggest misconception with today's check engine light diagnosis is that a technician plugs a computer into the car and it tells him or her what part to replace. If this were the case then the average check engine light repair cost would be next to nothing. Unfortunately, this could not be farther from the truth. The scan tool simply retrieves a code from the vehicle's computer memory that tells the tech why it decided to set the check engine light. For example it may give the technician a P0174 code telling him that the vehicle was running lean on bank 2. It knows this because the oxygen sensor readings told it so, but it has no idea what caused it to run lean. Determining this is the technicians job, and the amount of time it takes the technician to do this directly affects the check engine light repair cost. The tech can use the scan tool to monitor sensors that his knowledge tells him could cause the problem, or at least help him isolate the cause. He can also perform certain tests with the scan tool to check component functions, but ultimaltely it comes down to performing some hands on circuit and component tests as outlined in the diagnostic pinpoint test. So how much should a check engine light repair cost?

That is a loaded question but I will tell you my feelings and experience with this. There is no such thing as free diagnosis. If someone is making such an offer then you should really take a closer look. You are either going to pay as part of the repair cost once diagnosis is complete, or you're going to pay when the "free diagnosis" was incorrect and you have to return to the shop for follow up repairs that may be claimed to be "unrelated" or "additional" problems. All of this adds to the total check engine light repair cost. Sometimes a shop's idea of free diagnosis is simply code retrieval, which is essentially useless without performing the appropriate pinpoint tests. Having a code number is only marginally closer to knowing what's wrong with your car than simply seeing the check engine light on!

Most pinpoint tests will require removal of certain parts for component tests or access to connectors and wiring that must be checked. Again, adding to the check engine light repair cost. The technician will also likely need to perform multiple road tests while monitoring sensor activity and getting a "feel" for the driveability concern. Again, this will add to your immediate check engine light repair cost, but it will save you in the long run because a 10 minute road test before the repair can help speed overall diagnosis time and a brief road test following the repair will ensure the repair has been successful. There are some problems that are very common with certain vehicles and some technicians will quickly assume a specific part is needed as soon as they retrieve that "familiar" code. This is poor practice that will eventually spill over into other work areas and should always be avoided. This type of unneeded work also adds drastically and unnecessarily to your total check engine light repair cost. Even the most common of concerns should be diagnosed with a fresh perspective so that repeat repairs can be avoided. So if you bring your car in for inspection of the check engine light and you're approached within a very short period of time with a completed diagnosis you may want to be concerned! Ask what tests had to be done, and what the results were. At a bare minimum make certain they guarantee the results. There are a handful of concerns that can be found relatively quickly, such as an obvious vacuum leak or a spark plug wire that's misfiring, but most common check engine light pinpoint tests take between 30 minutes and an hour. Many shops charge a set fee for check engine light testing. This is good if you have the right technician working on your vehicle and checking things out completely, but not so good if you've got a tech playing part darts with your check book while he collects on his diagnosis time without doing the real work. You may want to take a moment to read our article on "Over Repairing" to get a handle on typical expectations of what may be needed to fix that check engine light. At least with a set fee the consumer is not going to get shocked with an outrageous bill for diagnosis and the shop will likely work more diligently to get the testing done in a reasonable amount of time. I can't imagine much worse than getting a bill for $100 only to be told more testing needs to be done! Always make sure that the results you paid for are guaranteed to correct the problem, and if not definately ask why.

So on to the bottom line. How much should that check engine light repair cost you? I would expect to be charged an average of 1 hour diagnosis time for most check engine light concerns. If you have a particularly difficult concern maybe as high as 2 hours, but no more. Anytime longer than this and perhaps the dealer should consider having another technician more qualified take a look at it. About once a year we have one come in that will take considerably longer, because it goes against some basic rule but we as a dealer absorb the additional cost of diagnosis. After all why should the consumer pay because the manufacturer didn't take something into consideration when writing out their pinpoint tests or sometimes the printed test procedures are simply wrong to start. Yes, this actually happens! So before dropping your car off, check out how much your servicing facility charges per hour for checking out these types of issues, or if there is a set fee, or cost cap on diagnosing check engine light concerns. If your not satisfied with their pricing, look around as there are many fair and competitive qualified shops. More importantly, remember, there's no such thing as "free" diagnosis and if you ever have a question about what your being told is wrong, or don't understand how something has been explained to you, ask us, we can help. So how much should that check engine light repair cost? Now you know! Have a great one!

The Team

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