Why The ‘Check Engine’ Light Must Be Banned

From Jalopnik:

It’s pretty easy to dismiss the “check engine” light as just stupid, because, well, it is. I suppose if you thought that the cause of smoke coming from under your hood had something to do with the floor mats, then, sure, the “check engine” light is handy, but beyond that, it’s useless. But that’s not the real problem. The real problem is that the “check engine” light is a tool for the propagation of consumer ignorance about their cars. Which is why it needs to die. Now.

If it sounds like I’m making a big deal out of this, it’s because I am. The continued use of a generic, uninformative “check engine” light in cars keeps car owners in the dark about the condition of their vehicle, and ensures they stay dependent and subordinate to car dealers and mechanics. The frustrating thing is it doesn’t have to be that way.


  1. Oh, that’s a load off my mind! Praise the Flying Spaghetti Monster! And here I thought those flames spilling out from the hood of my Honda we of some major/minor concern! PHEW! Dodged a bullet there. 😉

  2. First, you’d have to reinstate the teaching of auto shop and other shop classes in our schools. Even if the warning light told you what was wrong and how to fix it, nobody knows how too turn a wrench anymore.

    1. That is very true, but speaking as someone who keeps old cars running preposterously long I know how useful that info could be. Some of us old farts still know one end of a screwdriver from another. (Thank you, high school shop class! )

    2. Yes, it was a sad day when I found out my high school dropped shop classes. We’re it not for auto shop I don’t know how I would have survived high school, it was the only thing that kept me going. We fixed teacher’s cars for the cost of parts, got a ton of experience on many types of cars.

      Had I not gone in the USCG I had a scholarship offer for UTI in Arizona, still wonder how that would have turned out. 20+ years later the auto shop teacher is still there but teaches computers.

  3. Amen. There’s a wealth of valuable information available just under the hood of modern cars (that we OWN), and it’s deliberately kept as cryptic as possible. How about a wireless device that plugs into the OBD slot and communicates with an app on a smartphone? I would gladly pay for that.

  4. The check engine light came on while my wife was driving. She panicked & pulled into the nearest garage. They charged her $80 to plug the test in and determine that the gas cap was not on tight. Fuck the check engine light!

  5. I’m really not curmudgeonly, but all of today’s cars are so computerized that NOTHING can be fixed without big bucks. My husband took my car into the garage for a routine check and mentioned that the clock no longer works right, either doesn’t show up or keeps displaying the incorrect time. After learning that the whole front end had to be pulled out/rummaged through for $$$$, we decided a stickup clock would work just fine.

  6. Christ, for an extra $50 per unit on the production side your car could be made to text you what the problem is.

    “Check engine light? There’s an app for that.”

  7. Stick a seven-segment display where the check engine light is and just show the error code. Piece of cake, and would add 50 cents to the cost of the car!

  8. Whenever my check engine light comes on I always fix the problem with duct tape. Just cut off a 1-inch square piece and stick it right over the light.
    One time I did that and the car broke down anyway, so obviously the light is useless.

  9. The engine light on my 1995 Maxima has been on for the past 4 years. I put the car in at the Nissan dealer when it first came on, but they said that they all the sensors were fine, “so it must be the computer.” That would have been $600. I said no. Somehow, my local mechanic makes the light go away long enough for the yearly inspection. And the car still runs great (165,000 miles)!

  10. My husband’s car has an engine light on for a catalytic converter sensor. The car is still getting him to work (knock on wood) but because the light is on, jiffy lube won’t do an oil change.

    1. Just take it to one of the oil change places where you drive it into the bay yourself and turn the engine off. That way they will never know. And I live an an area with pretty harsh pollution inspections. We even have to buy E10 or MBTE gas to cut down on emissions.

  11. Who keeps giving the “thumbs down” to every comment? Is it another religious wacko putting us in our place because the Flying Spaghetti Monster was mentioned in the first post or some clever enthusiast from the National Engine-Light Manufacturers Association?

    1. They’ve been doing that to my comments for months. I rather enjoy it, actually. They say there’s no such thing as bad publicity.

  12. The whole point of having specialists is to ensure the person doing repairs knows what they’re doing based on training, experience, and having the correct tools. The same rant could be said about any profession, but who has the time or dedication to learn (much less, master) new skills to simply save some money when the occasion presents itself?

  13. I read comments elsewhere to the effect of “it would cost hundreds of dollars to actually display failures in plaice of the light.”

    Well, considering you can buy a cheapie OBD scanner tool for $25, it seems trivial to simply build that into the car. Since they’d be physically installed, it would be equally trivial to hard-code the actual diagnoses into the device, so that when your engine spits out a P0052 code, you know it’s a Right Side O2 Sensor failure. (well actually that’s a generic code, but vehicle specific codes could also be hard-coded)

    I’ve got a Diablosport Predator for my truck, which will read codes in addition to performance tuning. Carry it in the truck for diagnosis purposes.

    1. Even on my 1989 Escort and my brother’s 1988 Reliant K car you could turn the key on/off/on in a sequence and get the diag code. Of course in pre-internet days you needed the Chilton or Haynes manual to figure it out, but not sure that today’s check engine lights do that, gotta have the ODB plug-in

  14. Buy a scanner. They plug in under the dash. You can get a varierty of them for $100 give or take. They also allow you to reset the light which can be very useful when going to get a sticker. I live in Mass and you can’t get a sticker if the light is on. However it does take an hour or two for the car to completely cycle through all it’s tests and you won’t be able to pass inspection until all the tests are finished. So if the light comes back on in this time period you’re SOL. Worse case if you can’t buy a reader go to any autozone and they can read it for you. However they won’t reset the code. It’s illegal or something.

    I’ve had a P172 code on my golf for years. It’s in reference to the catalytic not running at full capacity and points the MAF (mass air flow sensor) and the O2 sensors. There are two O2 sensors, one before and one after the catalytic. The MAF is part of the air intake system. There is nothing wrong with the MAF or O2 sensors on my car since I’ve replaced all of them over time, yet I still get the 172 code. Come to find out my vacuum lines had a small leak in them. I got them replaced and the light is now off!

    This is the trouble with the check engine light system. It can be damn difficult to get to turn off as the codes often only point to the symptom of the problem and not the source. Often times mechanics will guess and throw something in, reset the light and hope for the best. Multiple times I’ve had work done to correct a check engine light problem only to have it come back in a few days or couple of weeks.

    I highly recommend checking around to see if there is an online message forum for you car. I have learned a lot from helpful guides on vwvortex and vwforum.

  15. A side-comment semi-related. Recently I pushed the envelope in my 2005 Chevy Cavalier and let the gas gauge get low enough to elicit the dash-panel warning, “CHECK GAGES” (sic!).

    Check the spell-checker, GM! 😉

  16. My service engine light is always on. Thankfully I have an honest mechanic who checked it for free and figured out it was a very minor emissions thing and nothing to worry about.

  17. Agreed. My “Check Engine” light is on and it just came out of the shop. From what I hear, there’s of course a sensor that needs to be reset (for extra money of course) when you get it fixed.

  18. The Apollo landing craft displayed the proper codes. 1201 and 1204 as I remember ( no I’m not going to google it to make sure ), someone looked them up in a few seconds and found out it was low fuel. If they’d had a check engine light they may never have got to the moon, cos they would have had to abort it, not knowing what the potential error was.

    Check engine light bad, diagnostic code display good. I rest my case.

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