The check engine light is the single stupidest warning light in existence

We now live in an era when so many cars come with screens for the GPS/Entertainment/HVAC systems, there’s no good reason why the cars can’t display, in plain if somewhat technical language, what the hell’s wrong with them.

But we’re also at a point where nobody bothers learning how to fix their own cars anymore (and they’ve gotten complicated enough where there are fewer and fewer user-serviceable parts anyway), so the screens might as well say things like “I don’t feel in tip-top shape. Can we schedule a service appointment in the next week or two? Shouldn’t take more than a couple hours and cost $200” or possibly “It seems a fuel line has burst, and though I have cut power to the fuel pump, I have nevertheless caught fire. Please pull over and exit the vehicle immediately, and don’t forget those 50-pound passengers in the back seat, as I suspect you may value them. Emergency personnel have been summoned. It has been an honor and pleasure to transport you in safety up until now. Please consider purchasing a Toyota next time.”

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So get your own Bluetooth code reader for $10 on Amazon. Should be one in every glovebox.

On Hondas, when the CEL comes on, the engine goes into “safe mode” which means mileage gets worse.

In me experience the CEL has always meant I’m about to shell out several hundred dollars. Bad catalytic converter etc.

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I’m pretty sure most cars will do that… I did it with my old Insight (kept a calibrated paperclip in the glovebox)…
Insight OBDII blink codes

Some of these products don’t seem to be easily available in Canada (translation: not on Amazon). I am looking at this: http://www.amazon.ca/gp/aw/d/B00JQW9NCE/ref=mp_s_a_1_2?qid=1416940803&sr=8-2&pi=SY200_QL40#

Any red flags I should be aware of from other OBD scanner owners out there? I have a 2008 Versa.

If my car ever said this to me, I would assuredly be willing to scare up a Genesis Device in order to repair it :wink:

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The interesting thing is that it would be very easy and cheap to install an LED readout that would provide the same code that the shops check for $80… Then you could just look up the code yourself…B-u-u-u-t that would reduce service calls and the opportunity to sell other products and services while you’re at the shop, wouldn’t it. :wink:

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My Jeep* will flash the codes on the odometer if you turn the key on-off-on-off-on. No looking up light patterns, you just read the numbers. I haven’t needed an OBDII reader yet thanks to this feature.

[*] and many other Chrysler products; it’s definitely all the JTEC equipped vehicles, which includes most anything with the 5.2L and 5.9L V8s, 4.0L I6 and Dodge Viper from 1997 through around 2004-2006. There’s some fuzziness on the end of the MY range due to different models getting updated in different years. I’m not sure if they’ve kept this feature or if it’s included on any other Chrysler ECUs.

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The check engine light is the single stupidest warning light in existence.

Because anything I don’t understand is STOOOPID, amirite?

Sheesh. If people were this aggresively ignorant about their computers or their cell phones, they’d be mocked and derided in these pages, wouldn’t they?

Personally, I’m having an anxiety attack right now because a light labeled “DRIVE” keeps flickering on and off on my computer. Am I supposed to go drive somewhere? But where? What does it MEEEEAAAAAAAN?

Stupid light.

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I think in that situation the oil pressure light is going to tell you something a lot quicker.

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The check engine light is simply an indication that something, somewhere on your car isn’t functioning exactly as it should. It might be something big, it might be something small. If you take it to a dealer it will cost money to check it out, but most auto parts stores (Auto Zone, O’Reilley, etc.) will check it for you for free. That way you can judge for yourself whether it’s an actual problem or not.

Don’t do this right before an emissions test. Clearing the trouble codes turns off the light but puts the car into a “Not Ready to Test” mode. Until some time has passed (about 24 hours, and that must include some periods of 55+ MPH and idling in traffic, among other things) there is a stored code that will not turn on the CEL, but it will let the emissions test station know there is insufficient data to pass the test. If you really do have an emissions related problem, it will turn the CEL back on by the time the car is ready to be tested.

As others have mentioned, if that light flashes, you really do need to get your car serviced soon. Flashing usually indicates a persistant misfire. This means raw fuel is being dumped into your catalytic converter, which can actually get hot enough to melt down when trying to burn the fuel off.

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Absolutely concur on all these points.

I live in NJ, which means I can’t pump my gas. We had a perpetual CEL issue that always came up as a result of the attendants not tightening the cap enough. These days I know that code by heart and when it happens every few months it’s the only code that comes up and I reset the thing.

Beats taking a day out of my life to run it into the mechanic for him to tighten the gas cap for me and reset the code.

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If it’s just the EVAP system code you get when the gas cap is loose, driving around after tightening the cap will allow the code to clear and turn the CEL off. You shouldn’t need to reset it for that.

Nope, ours stays on until that code is cleared.

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I recall an episode of CarTalk, http://www.cartalk.com/, they suggested having three lights, indicating $100, $1,000 or $10,000 of damage if you ignore it.

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We’re not the right crowd. I was talking to a mechanic the other day who works for Ford, and he told me that the heat gauge for most cars was “basically an idiot light” because its normal working range is compressed so that you don’t see the needle move. Because a moving needle was freaking too many people out. But for us here, yep, just get an OBD2 reader and something like Torque. And I have to add this: if you’re buying a Land Rover or, god help me, a Ford, you don’t need a light to tell you that you’re an idiot.

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Yup, the 1988 Fiero SE. The one and only year they got the suspension right. The car runs perfectly and it’s more fun to drive (IMO) than anything on the road today.
I think the problem people have with the car stemmed from the engine using under square (long stroke) cylinders. Over revving the engine does considerable damage and people just aren’t used to low RPM motors so they invariably over do it. Also, most Fiero’s have had the water pump replaced by someone who doesn’t know how to expel the air from the coolant lines.
It’s my ‘secondary’ car and not my daily driver. I plan to drive that little toy till the day I die or a better mid engine, long stroke, light weight car replaces it.

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I ran into a frustrating version of this issue with that 1997 Volvo 960 I mentioned in some other thread the other day. I had a leaking intake manifold gasket, so I went ahead and replaced my gasketry and buttoned it all up. Upon reattaching the battery cable, I figured I’d have to drive a few miles to get the car ready for a smog test, since, as you say, disconnecting the battery or erasing MIL codes puts the ECM into a default not-ready-for-testing state, and it needs to be driven for a while at different speeds in order for the fuel trim settings and ignition timing to calibrate themselves properly. But after a few days of driving and my code reader still showed that the calibrations weren’t complete, I got suspicious and headed to Ye Olde Internette for insight.

Come to find out, Volvo did something really dumb and shortsighted to certain year/models of their cars, including mine. After the battery is reconnected or the codes erased, one is required to drive in a demonically specific fashion for a stupidly precise number of miles in a fairly impossible-to-replicate sequence in order to reset the calibration. Something like idling for ten minutes, then driving at exactly 2,000 RPM for two miles, then idling for 10 minutes, then driving at 1,500 RPM for twenty minutes, etc. If you had a handy unoccupied racetrack or long and empty stretch of airstrip in which to drive, with no pesky stop signs, traffic lights, intersections, No Parking zones, or any other cars to worry about, you could do it in an hour. But any deviation from the prescribed routine means you’ve failed the sequence. How many freeways let you stop and idle at a precise moment when your odometer says you need to?

When someone pointed this out to CARB (the California Air Resources Board in charge of smog checks), they issued an order exempting these models of Volvo from needing to have that calibration sequence reset before smogging, otherwise none of those late-90s Volvos would ever pass their smog tests, no matter how cleanly they run.

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Automatic makes one that does the basic “check engine light” code reporting, and also monitors driving habits (kinda like a fitbit for your car), remembers where you park, and has a crash notification system similar to what OnStar does. Well reviewed recently by the New York Times. It’s $100, but at least there’s no monthly fee.

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