# Blinking Check engine light **URL:** \ **Category:** Factual Questions\ **Created:** [June 4, 2012, 12:39pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022 "2012-06-04T12:39:37Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [June 4, 2012, 3:48pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/21 "2012-06-04T15:48:54Z")
> [@kanicbird](#): > > The one hour charge for plugging in the meter and reading the code is borderline unethical IMHO -though perhaps they don’t want to be in the business of car code readers so overprice it to discourage it. If all you want done us the code read then take it to a auto parts store, call first to see if they do it for free - many do. If possible don’t heat up your car that much - take a direct route to the closest one that will do it, or buy/borrow a code reader taking another car. This, along with the internet, will give you some concept of what’s wrong and may allow you to fix it yourself. > > Then if it’s beyond you you can put the shop’s expertise to work. Unethical? How? Sure it only took a few minutes to pull the code(s) And now you have codes that read like this: Misfire on more than one cylinder Miss fire on more than one cylinder with converter damage Misfire cylinder #2 Misfire cylinder #3 O2 sensor out of range Catalyst efficiency Short term fuel trim out of range Long term fuel trim out of range So do you know what part to change? Oh you don’t? I do, and guess what knowledge costs money. You can pay me or you can throw parts at it yourself either way it costs money. ---
**Author:** ![dauerbach](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@dauerbach](https://boards.straightdope.com/u/dauerbach)\ **Post date:** [June 4, 2012, 3:50pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/22 "2012-06-04T15:50:38Z")
First, I definitely can decide if the charge is too much. I drive over 200 miles a day, and having my mileage cut by 1/3 is just too expensive to leave. If it was just the light, I would have told them to forget it, and found a place that would diagnose for free. I don’t have any problem with them charging $100 for a diagnosis IF I do not let them perform the repair. However, since they are doing the work I find the charge unreasonable. In the future, I will try to avoid going to this shop if I can. The problem is that it is right across the street from where I work, so the convenience is worth quite a bit to me. “you seem to lack the knowledge necessary to come to that sort of conclusion” Yes, jz78817 I do. But it seems that you do not. With what I have told you how long to you think it would take to confidently diagnose the problem? my 10 minute estimate or their one hour charge? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 4, 2012, 3:50pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/23 "2012-06-04T15:50:46Z")
> [@bucketybuck](#): > > I don’t know about auto-parts stores in the US, but in the dealership I currently work for you can be looking at about €14000 for the full diagnostic kit and it is mandatory to have it to remain a main dealer. > > I know there are cheapy cheap code readers floating about that give you a code and fuck all else, but if you want a proper diagnostic done, with injector tests or pressure tests etc etc, then you need the dealer, and they need to reclaim their costs. Nothing unethical about that whatsoever. > > Thats the other problem though. Many people still think we have magic diagnostic computers that tell you within five minutes whats wrong and how to fix it. Sometimes yes, but very often this is not the case. What you are talking about is quite different then the shop using a code scanner and I would expect you to know the difference - we are not talking about the same thing here. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 4, 2012, 4:10pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/24 "2012-06-04T16:10:02Z")
> [@Rick](#): > > Unethical? > How? > Sure it only took a few minutes to pull the code(s) > And now you have codes that read like this: > Misfire on more than one cylinder > Miss fire on more than one cylinder with converter damage > Misfire cylinder #2 > Misfire cylinder #3 > O2 sensor out of range > Catalyst efficiency > Short term fuel trim out of range > Long term fuel trim out of range > > So do you know what part to change? Oh you don’t? I do, and guess what knowledge costs money. You can pay me or you can throw parts at it yourself either way it costs money. You make a good point **Rick** but you are going into more then just code reading and still does not address the ethical issue of multibilling the same tech for the same time. ---
**Author:** ![Morgenstern](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@Morgenstern](https://boards.straightdope.com/u/Morgenstern)\ **Post date:** [June 4, 2012, 4:18pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/25 "2012-06-04T16:18:33Z")
> [@kanicbird](#): > > The one hour charge for plugging in the meter and reading the code is borderline unethical IMHO -though perhaps they don’t want to be in the business of car code readers so overprice it to discourage it. If all you want done us the code read then take it to a auto parts store, call first to see if they do it for free - many do. If possible don’t heat up your car that much - take a direct route to the closest one that will do it, or buy/borrow a code reader taking another car. This, along with the internet, will give you some concept of what’s wrong and may allow you to fix it yourself. > > Then if it’s beyond you you can put the shop’s expertise to work. It’s not so easy. Unless you have access to the TSB’s from the factory, you will likely miss many things. It’s not unheard of for one system malfunction to cause a failure in another system. You can change parts, but fixing the problem may be another matter entirely. It all comes down to a simple rule; you get what you pay for most of the time. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [June 4, 2012, 4:29pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/26 "2012-06-04T16:29:00Z")
> [@dauerbach](#): > > First, I definitely can decide if the charge is too much. I drive over 200 miles a day, and having my mileage cut by 1/3 is just too expensive to leave. If it was just the light, I would have told them to forget it, and found a place that would diagnose for free. There isn’t a shop who wants to stay in business that’ll _diagnose_ for free. Reading codes is not a diagnosis. Reading the diagnostic code is equivalent to telling your doctor “my shoulder hurts.” You need the doctor to figure out _why_ your shoulder hurts. > [@](#): > > In the future, I will try to avoid going to this shop if I can. I have a feeling that might make them happy. > [@](#): > > Yes, jz78817 I do. But it seems that you do not. With what I have told you how long to you think it would take to confidently diagnose the problem? my 10 minute estimate or their one hour charge? Look at **Rick’s** post above. Your car was saying “my shoulder hurts.” It was not saying “I have a torn rotator cuff.” ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [June 4, 2012, 4:44pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/27 "2012-06-04T16:44:17Z")
I find it amusing that people who lack the expertise and equipment to properly test and evaluate modern automotive performance problems seem to believe they know what the fees ought to be for such service. When I use my $3000 scan tool (with ~$1500/year software updates), $2000 lab scope, various other tools, ~$2000/year professional information service, 40 years of experience and knowledge – not to mention general overhead to maintain the repair facility – in order to efficiently and accurately diagnose a problem, you’re darn tootin’ I’m not going to charge just a few dollars to do it, even in those few cases where it can be done in several minutes. Of course, if you don’t like my prices, you’re welcome to go elsewhere – or better yet open your own shop, charge what you think it should be, and put me and those other “unethical” shops right out of business. Be warned, however, that over the years I’ve seen scads of low-priced auto service providers come and go – with the emphasis on “go.” They never last. Apparently it costs more to acquire the resources to do auto repair than a lot of people realize. One would do well to keep in mind the old adage, “You get what you pay for, and you pay for what you get.” ETA: One would also do well to let go of the notion that time spent is the criterion for diagnostic fees. Those fees are based on many factors (some of which I listed above). That $100 being discussed is not simply for a given amount of time. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 4, 2012, 4:52pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/28 "2012-06-04T16:52:57Z")
> [@Gary\_T](#): > > ETA: One would also do well to let go of the notion that time spent is the criterion for diagnostic fees. Those fees are based on many factors (some of which I listed above). That $100 being discussed is not simply for a given amount of time. Yes, I do see that in Rick’s post also and agree it is a good point. Diagnosis only is a bit different then having the repair done. ---
**Author:** ![dauerbach](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@dauerbach](https://boards.straightdope.com/u/dauerbach)\ **Post date:** [June 4, 2012, 5:32pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/29 "2012-06-04T17:32:23Z")
So is the take home message here that a reasonable charge is whatever the mechanic feels like charging? Has anyone ever received a dentist or physician bill that they felt was unreasonable? ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [June 4, 2012, 5:42pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/30 "2012-06-04T17:42:33Z")
Goofed up duplicate. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [June 4, 2012, 5:43pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/31 "2012-06-04T17:43:34Z")
> [@dauerbach](#): > > So is the take home message here that a reasonable charge is whatever the mechanic feels like charging? No. It’s generally not that capricious. There are standards and conventions, as well as marketplace forces involved. The message is that a reasonable charge is not necessarily what the consumer feels like paying. > [@](#): > > Has anyone ever received a dentist or physician bill that they felt was unreasonable? Sure, and many similar factors come to bear. Just because it doesn’t seem reasonable to the layman doesn’t mean it’s unreasonable when one considers education, experience, equipment, overhead, and all the other things that make it possible for the dentist or physician to provide the needed service. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [June 4, 2012, 5:43pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/32 "2012-06-04T17:43:52Z")
> [@dauerbach](#): > > Has anyone ever received a dentist or physician bill that they felt was unreasonable? ask anyone without insurance. ---
**Author:** ![dauerbach](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@dauerbach](https://boards.straightdope.com/u/dauerbach)\ **Post date:** [June 4, 2012, 5:47pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/33 "2012-06-04T17:47:21Z")
I will take that as a yes. It seems that, in general, people tend to think that the price charged by professionals they need to consult are too high. And you are correct, I do not have auto repair insurance. ---
**Author:** ![Hbns](https://avatars.discourse-cdn.com/v4/letter/h/8edcca/32.png) [@Hbns](https://boards.straightdope.com/u/Hbns)\ **Post date:** [June 4, 2012, 5:53pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/34 "2012-06-04T17:53:36Z")
The $100 dollar flat rate for diagnosis is pretty common from what I have seen. More akin to a cover charge in my opinion than a direct rate charge. I know of a few shops that “rebate” the diagnostic fee if they do the repair. Funny thing is, the total service charge just ends up being the same as the other shop that leaves the fee in. I don’t see a lot of difference in price in my area. I tend to believe that computers and estimating software services have pretty much made charges consistent across the big shops in any given area. Maybe one of you guys in the industry can speak to the validity of this belief? ---
**Author:** ![Morgenstern](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@Morgenstern](https://boards.straightdope.com/u/Morgenstern)\ **Post date:** [June 4, 2012, 5:53pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/35 "2012-06-04T17:53:39Z")
You can buy hay, or you can save money and buy hay that has been run through the horse once. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [June 4, 2012, 5:55pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/36 "2012-06-04T17:55:33Z")
again, what someone “feels” is unreasonable and what _is_ unreasonable aren’t exactly the same thing. When I wrenched, I actually had this conversation with a “customer:” Customer: “How much is it to change the plugs and wires on a 1994 Furd Mongoose?” Me: “$Texas.” Customer: “Can you do it right now?” Me: “Not 'til this afternoon, I’m working on two appointments this morning.” Customer: “Well, I guess you don’t want to make any money.” :rolleyes: I’m sure he “felt” I was being unreasonable for not dropping everything I was doing to accomodate him. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [June 4, 2012, 6:12pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/37 "2012-06-04T18:12:44Z")
> [@Hbns](#): > > I don’t see a lot of difference in price in my area. I tend to believe that computers and estimating software services have pretty much made charges consistent across the big shops in any given area. Maybe one of you guys in the industry can speak to the validity of this belief? There’s something to that, but there can still be a fair amount of variation. Shops have several estimator services to choose from. Those estimators tend to be fairly close to each other on most things; however there are a few significant differences here and there, and while most shops rely on them quite a bit they have no obligation to follow them. Market pressure is a big factor toward the consistency you’ve observed, but still some shops charge noticeably less than average and some charge noticeably more, at least in some (mostly urban, I suspect) areas. A lot of shops set their prices largely by what’s common in their market. Some make more complex calculations of their costs and profit goals that sometimes result in noticeable deviation from the majority. There are limits, on the one hand prices too low to sustain the business, and on the other hand prices so high they drive customers away. One can’t vary too much from the norm without running up against that. ---
**Author:** ![bucketybuck](https://avatars.discourse-cdn.com/v4/letter/b/898d66/32.png) [@bucketybuck](https://boards.straightdope.com/u/bucketybuck)\ **Post date:** [June 4, 2012, 6:22pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/38 "2012-06-04T18:22:14Z")
> [@kanicbird](#): > > Diagnosis only is a bit different then having the repair done. Again, you seem to be one of those who believes diagnostic computers and fault codes are magic wands that fix cars like clicking your fingers. Fact is, its not like that, not for real mechanics. Five minutes in and you have the fault code MID 136, PSID 28, FMI 1. What then Kanicbird? What you going to do with that code? A parts store will tell you that it is the code for a part, and then laugh all the way to the bank while you throw parts at the problem. A garage, whom nobody wants to pay for apparently, will spend time and expertise checking the wiring to the ECU’s, saving you hundreds in the long run. Those bastards. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [June 4, 2012, 6:33pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/39 "2012-06-04T18:33:00Z")
I thought that the “Check engine” light was an attempt to warn the driver that a mechanic may have used knockoff Eastern European parts to repair the car. ---
**Author:** ![Gary\_T](https://avatars.discourse-cdn.com/v4/letter/g/3ec8ea/32.png) [@Gary\_T](https://boards.straightdope.com/u/Gary_T)\ **Post date:** [June 4, 2012, 6:46pm UTC](https://boards.straightdope.com/t/blinking-check-engine-light/624022/40 "2012-06-04T18:46:01Z")
> [@kanicbird](#): > > Diagnosis only is a bit different then having the repair done. True. It typically requires a higher skill level and the use of more expensive equipment. It also typically involves no parts sales, thus meaning that for the time involved all the necessary profit must be generated from the labor fee. [Previous page](https://boards.straightdope.com/t/blinking-check-engine-light/624022.md?page=1) [Next page](https://boards.straightdope.com/t/blinking-check-engine-light/624022.md?page=3)