3096: Check Engine

Check Engine

|< < Prev #3096 (May 30, 2025) Next > >|

Title text: They say it's probably safe to keep orbiting for a while, but if it stays on or starts flashing we might have to call someone.

|< < Prev Random Explanation Next > >|

Explanation

This explanation is incomplete: This page was created by THE SOLAR PIT CREW. Don't remove this notice too soon. If you can fix this issue, edit the page!

Sunspots are temporary, relatively small, darker (because cooler) regions on the surface of Earth's Sun. The number of sunspots that can be observed varies over an approximately 11-year cycle. The current cycle is the 25th since reckoning began in 1755. Solar Cycle 25, which began in December 2019 and is expected to peak around mid-2025, has been more active than anticipated, raising some concerns about the impacts of recent solar flares and associated space weather events.

The joke in this comic is that the sunspot array shown has taken the form of a "Check engine light", found on the instrument panel of most automobiles. The illumination of this light means that the automobile's onboard computer has detected an engine malfunction, which should be checked out by an experienced mechanic. For such a signal to appear among the nuclear fires and plasma of the sun would most certainly be of concern to astronomers.

Many drivers will barely notice a Check Engine light, and may hope that they never have cause to see it appear except maybe briefly during the turning of the ignition key as one of the bulb-checks. If it lights persistently before or during driving, it could mean a costly problem, or at least the inconvenience of paying someone to investigate the problem. Frequently, such investigations reveal no identifiable issue with the engine itself, resulting rather from some kind of sensor fault. In this case, the advice may be that it's probably OK to keep driving unless the behaviour of the light changes, and fixing the sensor issue may cause more expense than the small risk of a genuine engine issue arising would warrant.

As we don't appear to be cycling the Sun's ignition process (i.e., it hasn't recently stalled, which would be a worry in itself) the showing of the light/dark-patch would probably be very concerning, and hopefully someone at least has the owner's manual in order to run through any initial troubleshooting, before perhaps a more extensive check is made at the local solar-repair shop to clear the error. Given the rotating nature of the star and Earth's orbit, one might also wonder how long this, or any other warnings, might be shown before becoming visible to suitably equipped viewers of the Sun.

The title text says that "they" (presumably the astronomers) advise that it's probably safe for Earth to continue to orbit the Sun unless and until there is a change in the nature of the "check engine light" sunspot array. Such a change, on an instrument panel, signals that the matter needs immediate attention, lest something dramatic and expensive occur, such as an engine seizure, which can be spectacular and is irreparable. The solar equivalent of an engine seizure would be a nova, which would definitely be of concern to astronomers (and everyone else), and for which the prospect of "calling someone" that can do anything useful (a cosmic tow truck to pull Earth to a safe distance?) seems remote.

Transcript

[In a black panel a large orange Sun-type sun is shown, depicted as it might look when viewed through solar eclipse glasses. A pattern in the form of a "check engine" light (as displayed on a car's instrument panel) is shown on the surface of the Sun, in the bottom right quarter. The pattern has a pictogram of a motor on the top with text below it, both in orange inside a black square, matching the orange shading of the rest of the Sun.]

Check Engine

[Caption below the panel:]

This new sunspot cluster has raised concern among astronomers

  Add comment        Create topic (use sparingly)       Refresh 

Discussion

Cosmic tow truck? I've seen that in the youtube vids where a guy makes the sun grow increasingly larger in minecraft and the villagers built a "tow truck" to tow the sun. --me, hi (talk) 18:26, 31 May 2025 (UTC)

"The Check Engine light is one that drivers will rarely see". Well, in most cars, you'll see the "check engine" light every time you put the car in "accessories" mode, just temporarily, as a test to make sure the light works. So car owners will know that the light is there and exists, and to not ignore it if it comes on outside of being in "accessories" mode. Dogman15 (talk) 19:39, 31 May 2025 (UTC)

Reading up on "Accessories Mode", I'm confused as to which level of key-turning that is. May be different in different models of car, but I'm going by the various makes of car I m used to.

Key position 0: Key inserted (or not), no twist. Minimal 'accessories' available - no wipers, indicators (except full hazards), radio, air, "lighter socket". Nothing lit on dashboard (except both indicators, in synch with hazards).

Key position 1 (maybe, if not straight from '0' to '2', deending upon vehicle make): Unpowered as 0, but key is 'locked' in so it can't be pulled straight out

Key position 2: Power to (practically) everything internal, and (?)individual indicators if either difection active, with engine off. Minimal dashboard lghts on, as necessary for (side-)lights, and 'glow light' illuminating the physical dials (dimmed, if head-/dipped-lights are on, as a less obtrusive 'night mode). I'd call this "accessories mode", would need to check my current car manual to find out what it calls it, but it doesn't show all lights (engine check, battery fault, seat-belt-unused warning for seats with sufficient weight on them but not clipped in as required).

Key position 3: "Driving" position, once engine is started, only things that matter show.

• But if left in this position without going through Pos4, will show many (all?) lights in general "many things aren't actually working" mode, perhaps. Tend not to dwell on this state (if starter-motor isn't working, even, no point leaving it like this while working out what help is needed to jump-start/jumper-start/etc). Will have to check what lights do/don't illuminate, or flash on momentarily, but normally only an issue if there's a problem.
• If the engine stalls (awkward hill start at a junction when the lights suddenly change, and messed up with the clutch-pedal 'bite'..? We've all done it at least once, don't judge me!), I'm fairly sure the "many things not working" doesn't fully show, in the small amount of time it takes to clutch-and-brake and redo the engine starter (before pulling away, sheepishly, making a "sorry" hand-signal to the car behind who might or might not be wondering why you didn't quite move when you initially might have done).

Key position 4: "Starter" position, sprung so that (upon ignition, hopefully) twists back to 3 upon release. Couldn't tell you what lights light (without going to the current car and firing it up), except that the battery symbol might accompany the "click click click" of the starter motor failing due to... well, bad battery. Pretty sure only the 'necessary' pictographs show.

All pretty consistent in cars driven from early '80s to present day. Only real change is that the earliest cars used to have a physical "choke"-puller (at least for cold-day starting, less so at other times), whereas the very latest vehicle manual explicitly tells you not to press the accelerator pedal on starting (something I now have to resist, due to muscle-memory and that having been part of the process for... well, decades), obviously having progressed from auto-choke through to the box of fly-by-wire electronics now also being in charge of the precise amount of throttling necessary to kick the engine into life.

I do tend to read the manual whenever I get a new car (every 5-10 years, I think), but really don't bother much until something goes wrong (working out which fuse blew that means the lighter-socket isn't working, e.g., and whether that's in the hatch under the dashboard or in the box under the bonnet). It's so easy to forget that there is an ABS-warning light, if you don't ever cause its warning to happen, then read the manual and learn that it's one the (normally) unglimpsed 'gap in the lights' on the lower row of an array of glyphs that normally you only ever see the upper set being active.

So, yeah, maybe I can see the ECL, but I have to say that I'd probably never notice it (or its absence), as I'm probably doing things like a mirror-check during the moment of twisting the key from '2', past '3', temporarily into '4' then back and ready to get into gear and go when it's expedient and safe to do so. But don't know how universal this setup tends to be. Sounds like it matches the scenario you're questioning, but I don't think I can improve what's there by adding this longhand personal understanding. Could be shortened. Maybe the original author wouldn't mind something like "most people probably never notice the ECL until it comes on and stays on", if that's not too much against the spirit of your expectations. 172.71.241.166 22:17, 31 May 2025 (UTC)

My thought FWIW is that the "Check Engine Light" falls within the experience of most drivers (most of the audience for xkcd and explainxkcd) and hence shouldn't require explanation beyond what is in the cited Wikipedia article. Indeed, the humor arguably works because of the reader's immediate "Holy [deleted]!" recognition of, and reaction to, the light - however it may be produced. As for the "black patch" mode of producing the image, that is (I read, again via Wikipedia) precisely how sunspots are contrasted from the rest of the sun's surface, as they are cooler and have higher magnetic field strengths. I'm not sure how discussing the manner of producing alert signals on automobile dashboards and LCD screens, and contrasting that with the Sun, contributes positively to the explanation. One can perhaps contemplate the design challenges of producing an image, several Earth diameters across, that means something to humans in an environment of 28g gravity, 5700 degrees K temperature, and 4500 Gauss magnetic field strength, never mind one that accurately reports a fundamental problem with the Sun's "engine".108.162.245.161 23:28, 31 May 2025 (UTC)

"It "proves out" the dash warning lights. You turn the key to on, the dash lights for oil warning, brake warning, etc. come on for a couple of seconds and then go out. This is to show/test the bulbs work before starting the car. Bulbs don't prove out then you have burnt out bulbs or a dash wiring issue. This way you know the bulbs work BEFORE you have a problem with oil pressure, charging system, etc." VMF In many states the "smog check" is just to observe no Check Engine light. But what if the bulb burned or fell out (it has happened!)? The inspector is supposed to observe that key idiot lights DO light for a few seconds at turn-on. Another article states that only 21% of UK drivers can identify dash warning lights. --PRR (talk) 04:46, 1 June 2025 (UTC)

It's the one marked "Acc" – that's short for "Accessories". Lock, Acc, On, Start. Yorkshire Pudding (talk) 14:53, 2 June 2025 (UTC)

Checked my own vehicle. It's not 'marked' anything. Just four dots.

The manual does describe the as LOCK, ACC (Accessory), ON and START, but... well, I'd never have read it that closely except for this question.

Can confirm, though that you don't get bulb-test at "Acc" level. It's "On" where "The warning lights can be checked before the engine is started."

Regarding the warning lights, I have ...potentially 26 lights, according the manual (16 of them marked "if equipped", including the one with the 'engine' shape that is described as "Malfunction indicator")... But I don't think even half of them get a "bulb test" treatment. The engine one does, but goes away very quickly as I agree that one doesn't tend to dwell on "On, but not Started, I agree, and the manual actively discourages you from staying in the "On" position, like that. 172.70.58.20 21:19, 2 June 2025 (UTC)

My own information on this (tried yesterday, when the site was a bit broken, but when I could bothered to go and dummy-start the car) is that the On-but-not-Started position progressively illuminates various lights on the dashboard console. Initially, only the oil and something else (took a photo, turned out to be blurry!), then various other 'warnings' in several steps of maybe a third or half a second. Ended up with eight lights permanently lit ('engine' one after two such steps... as with the 'battery' symbol, I think), including seatbelt (which was a legit complaint, at the time of the test, as I hadn't donned it and wasn't intending to drive away anyway) and excluding headlights/dipped lights and indicators (probably because they can be tested through invocation). Some discernable unlit light-spots probably refered to uninstalled features, like tyre-pressure warnings, which would never rightfully have opportunity to light.

When I subsequently (yesterday evening) did start the car, to actually drive it, I saw that there wasn't time for the Engine light to show (the oil and whatever-it-was blinked on, then off again) before I got the lock over to the Starter position and back and subsequently just got all the 'real driving conditions' lighting configuration without seeing all possible 'bulb test' ones lit. At which point I was too busy to try a (further) photo or make extensive notes, but I can say, personally, that (in this vehicle, at least), I will probably have rarely seen the Engine light (and, if so, paid it no heed, as a blink-and-you'll-miss-it think). The most time it will have shown is when I've needed the ignition briefly On (not just for regular Accessories, which gives internal power to the radio, etc) to adjust the opening/closing of the electric windows, at a time when I'm stationary and not even expecting to need to look in the direction of the console for any reason.

I could not convince myself to invoke an engine-stall, to see what lit then, as it feels bad enough when it happens through driver error.

As a bulb-diagnostic, yes it exists. But I'll be glad enough never to deliberately invoke it. That near-universal 'engine shape' is a strange one, and why (in my vehicle) is it white? You'd have thought yellow/warning would be better, if not more red-hued if it truly intimates to bode potentially imminent ill fortune. White's too... neutral, semiotically.

And, unless I've missed it, I'm surprised that nobody's linked Sunshine (2007 film), yet. (Sun 'stalls', etc, the mission(s) to fix it relies on a dark spot...) 82.132.234.190 13:12, 5 June 2025 (UTC)

uh oh 172.69.134.55 01:11, 1 June 2025 (UTC)

Is there perhaps some joke related to it being a cluster of sunspots, and the place where the Check Engine light would be on a car is called an instrument cluster? 162.158.211.30 11:54, 2 June 2025 (UTC)

Don't think so. Maybe if more than one "warning light" had been shown, e.g. "high temperature" in addition to "check engine". (Pauses briefly to contemplate the implications of a "high temperature" alert becoming visible on the surface of the Sun ... weoweoweoweoweo.)172.71.146.215 14:12, 2 June 2025 (UTC)

Low fuel would be quite bad too.172.69.224.201 16:24, 2 June 2025 (UTC)

Possibly coincidence, but a strong (G3) geomagnetic storm was observed on or shortly before Thursday, May 29, 2025 03:09 UTC, the day before this comic was published. Severe (G4) conditions were observed in the following days. 172.70.94.35 18:33, 2 June 2025 (UTC)

Could this be connected to [1]? 162.158.62.166 (talk) 23:43, 2 June 2025 (please sign your comments with ~~~~)

Diagnosing this will probably require plugging in a comically oversized OBD2 reader to the port tucked away under the photosphere at the south pole. 172.70.110.143 12:55, 3 June 2025 (UTC)

This reminds me of a certain Andromeda episode: https://www.imdb.com/title/tt0789802/ 172.68.35.64 (talk) 15:52, 3 June 2025 (please sign your comments with ~~~~)
        Add comment