I was running errands on a Mercedes S-Class tester on Sunday and suddenly I saw the "Check Engine" light turned on.

"Well, it's weird," I thought to myself. Especially because the car is running and driving well.

Sure enough, the light went out the next morning.

I checked the news fleet and was told that the dealer had performed a remote scan (I didn't even know it was the same thing) and found that the car needed to update its software. So, it's no big deal.

But I have to wonder-if the Check Engine Light (CEL) doesn’t tell me, the driver, what’s the problem, and what’s the point of it. I don’t know if there is a problem with the emission components or on-board diagnostics, or if the previous driver did not tighten the fuel tank cap (I did not fill the car with fuel or otherwise touch the fuel tank cap). All I know is that there is either a problem or the computer thinks There is a problem, but the car has not encountered obvious driving performance problems.

We need a better system. I'm just not sure what it is.

Of course, pop-up error messages with specific problems can confuse the public. Most drivers don't know the spark plug of the plug cord. You can't expect ordinary drivers to read the error message on the dashboard and know when to go to the dealership and when not to go.

But on the other hand, many drivers do rush to the dealer at the moment they check that the engine light is on, even if they eventually find that they just didn't tighten the fuel tank cap. Other people, usually those who drive old cars that are out of warranty, will ignore CEL because either they can’t afford the overhaul and/or they have driven the car before, but find that the problem is small and it’s not worth the money. .

The current system setting is that if your CEL is turned on, you usually need someone with a scanning tool to insert and find the error (or, I guess, you can get a software update). Of course, the scanning tool is not the exclusive domain of professional and technical personnel, but whoever is using it needs to figure out why the light is on.

I have never accepted such non-specific ideas from CEL, because OEMs want you to spend money on diagnostics instead of solving the problem yourself. That's because if the customer pays for the work, the money spent on labor will go to the dealer, not the OEM. If it is the warranty work, it will cost the OEM's money. What's more, consumers sometimes choose independent stores.

But I do find it annoying that CEL pops up, and I, the driver, don’t know why. Not knowing how much I need to worry about is something that makes me anxious.

Yes, I know, we all hate people who point out obvious problems without suggesting a solution. Sorry, I didn't get anything. All I know is that there must be a better way.

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You should be able to get the code without a scanning tool.

But at least you can, and through the code, it will usually tell you what went wrong, Google will link you to the part you need, and guide you step by step how to replace it through a YouTube video.

Yes, I know some cars don’t need tools. I know an old car, you can use a paperclip to make it shine. My point is more general-what is the use of such a vague error message light, which can cover faults as small as a loose fuel tank cap and as large as "stop immediately and call the trailer"?

right. Those are cars before the OBD 2 system. You use a paper clip to jump some contacts, and then count the flashing lights to get the fault code. However, the system is still cumbersome, especially in a world where *every car* has a pixel-based screen somewhere inside—very unnecessary.

Mopars you just cycle the ignition 3 times without starting and leave it in the running position.

If the ECU detects a fire, it will flash MIL. Some cars can distinguish the fuel tank cap and flash the message.

It would be great if you have access to some kind of in-vehicle system that can at least provide you with the code and "simple English" explanation, and then allow you to reset the content without the need for scanning tools. Perhaps after doing so, the code data can be stored somewhere until the scanning tool performs a "complete reset" of the system (or if the battery is unplugged).

The bigger problem is that when the battery voltage drops enough to make all the nanny systems lose communication, the dashboard will turn into a Times Square with warnings. Just flash a low voltage message, or "possible charging problem," and provide the driver with a way to reset without visiting the dealer.

Yes, I should be able to change the battery in the parking lot of my auto parts store without having to use some kind of electronic device to make the car happy! (Looking at you, BMW!) Take out the old battery, connect the new battery, reset the radio preset, and you are done! All babysitters should work immediately, and after driving a few miles, emissions should be ready for testing.

Now, our cars are equipped with on-board computers that can do anything, including parallel parking and driving vehicles, but these magical computers cannot show in simple English why the check engine lights are on. This can be very inconvenient, especially if you are driving in a remote area of ​​the country, away from car dealers, car service centers, or auto parts stores. I purchased an OBD reader just in case I checked the engine lights when I was traveling through the remote areas of North Dakota and Montana on a recent off-road trip. The information I can get from an OBD reader should be easy to display without having to carry a portable scanner.

This is the correct idea.

Of course, one of the 4 screens in the car can display the problem. When the door is opened, the parking brake is turned on, the key is left in the ignition switch/car, the brake needs to be pressed to move out of the parking gear, and the trunk is opened, the car can tell you to change the oil, and the windshield wiper fluid is low, below 37. The road may be icy, one of your tires needs air, and the coolant temperature is too high. When the stability control is activated, it will not tell you that the MAF sensor is not getting enough current or the cylinder 2 is too thin? Well, the data is there. The car knows what went wrong, why can't it tell you?

The reason is that most people simply don't know how to use their vehicle screen to pull fault codes. A $10 dongle and a free app are the only things needed for basic diagnosis.

This is the correct answer. A little knowledge can be dangerous. Most people don't know how their car works. If an error code that is more complicated than "Door Ajar" suddenly appears, ordinary drivers will not know what to do. These people need to find someone who can diagnose the problem.

For the rest of us who have a little car knowledge, a $20 scanner and a quick Google search will tell us whether our car has a serious problem or just a small fart.

Some people will insist that the door is actually a door! Not a jar! (At least the people from the Chrysler voice alarm system did this! :-D)

Yes, the average car price is close to 40,000 USD. They can’t use the 30.00 USD technology you can find on PepBoys?

On the other hand, if the code pops up a mysterious description such as "PC Load Letter", it may cause more damage.

I am not a coder, engineer or mechanic... but it seems that all the elements are there, cheap and can be easily integrated into the vehicle. It will be better than a vague CEL.

Yes! If you can't simply check the engine, code number and short description, what is the meaning of the central instrument oled display? This seems to be easy to accomplish, and now there is a lot of screen space.

According to my limited understanding, the blinking CEL is worse than the stable one.

[@Tim, with my 1995 GMT400 (one model year missed OBD-II), in order to read the (more limited) code, you use a bent paperclip to short between the two terminals, and the truck flashes the code to you, Morse code style. Would you like that better? I do not. ]

OBD-II is wobbly, you don't need to wait to check the engine light to get very useful information from the vehicle. I have started the engine scanner "registration" of my child's vehicle (check fuel adjustment, check oxygen sensor "switch" mode, check misfire count, evaluate engine vacuum, etc.)-because they now live 100 miles away [and I I really like to follow my own schedule and carry out any repairs in my own driveway].

Scanners are also useful when looking at second-hand vehicles (did you know that the engine computer will record the time since the fault code is reset?).

I have completed the cip thing on paper on Sierra in the 90s.

Yes. Generally, a flashing CEL indicates active misfire, which means that one or more of your cylinders are not burning completely or not burning at all.

Yes, a flashing CEL is worse, because it usually indicates an active fire. Unattended active misfires can cause even bigger problems-unburned fuel from unfired cylinders ends up in the catalytic converter, which can overheat and destroy it, eventually triggering P0420 (catalyst efficiency error). Big money.

The biggest problem with checking engine lights is that many drivers don't know what it should be. Replace it with the $$ icon, it will make more sense.

Lol i can see it now. Customers enter the service department thinking they will receive money! !

You can let it tell you what went wrong, but ordinary people don't know what to do anyway. The inspection engine seems to be working fine for the public. If you don’t need a scanner to view the transaction content, that’s great. The indicator light comes on and you tap the screen, it tells you that you forgot to fill the turn signal or the kanuter valve is malfunctioning. Ignore or frighten and go to the mechanic, your privilege :)

CEL only applies to emissions-related failures. Low cleaning fluid, low tire air, etc. have their own indicators.

But be clear that "emissions-related" will include things such as a damaged spark plug or ignition wire causing a misfire and dumping unburned fuel into the catalytic converter. This is something that needs to be dealt with as soon as possible.

I bought my e91 BMW with CEL two years ago. "Small evaporation leak" codes are very common. It took me two and a half hours to restore the car to specifications—all sellers agreed—but my mechanic would not even bother with the code. I have a Bluetooth code reader and Torque Pro just to make sure that no other code is also triggered, and the stupid CEL stays on known (non-)issues.

Torque Pro used to be able to erase code, but it is no longer the case. Does anyone know what else can be done?

I don't know what Torque Pro is, but if it can no longer clear the code, maybe your mechanic's code reader can't either?

This is exactly why they won't tell you the problem. More people will ignore things like small evap leaks if they are new.

Obviously, EVAP codes are difficult to diagnose. If you study "Mode 6" and get an application that can read these values ​​for you, then you can better understand what is happening in the EVAP system. Between this and the smoke test on the line, you may be able to find the bottom of it.

Nick_515, if the EVAP leak is indeed repaired, I believe the code should clear itself after a certain number of driving and parking cycles without failure. The EVAP code may take a while to clear because the car must be parked and cooled to test the evaporative part. But what about two years later? This means that there may still be faults there.

Although the EVAP code points you in the right direction, finding the exact location of the fault may be something you must use critical thinking and simple tools to diagnose old-school style things. Take a bicycle pump and a plug and see if you can build and maintain a few PSI in the fuel system through the fuel filler port. If not, there must be a leak in the EVAP system.

CEL only applies to emissions-related failures. Low cleaning fluid, low tire air, etc. have their own indicators.

It was originally used to ignore components worshipped by the almighty ManBearPig. Any actual driving performance or safety issues are irrelevant, it really should be a "$" sign, because this is what it really means: you will pay for it or solve it yourself.

There is an option. There are new car models without CEL lights on sale.

No, but they will receive a "5% battery life, pull over now" alert!

But this is not surprising.

@28-Cars-Later: "No, but they will receive a "5% battery life, pull over now" alert!"

In fact, they do exactly that, but you will be directed to the charging station. However, ICE cars have the same thing. Low fuel oil lamp.

You may have access to data that I don’t have, but the battery will lose power over time. Although gasoline can also degrade, it takes months to burn. I can park one of my cars for two weeks with the same amount of gasoline. If I park my hypothetical Leaf for the same amount of time, how much power will decrease during that time? How about winter and summer? I don't want to fart on the nuances of these things and continuous charging like a computer. HSD hybrids will do well as a DD.

In fact, I have parked Bolt for two weeks several times, once in mild weather and once in cold weather. During that time, it lost one percent or two percent of its electricity.

You can completely avoid any loss by plugging it into a power source. If plugged in, it will stop charging when fully charged, and then start charging again when it loses a few percent.

Thanks, I imagine it works like a laptop or a mobile phone. Given that my driveway is steep, I usually don’t park my car in winter, so I run 120 or 240 lines on one side of the driveway to the top, and then in January/February at -5 degrees to 30 degrees throughout the winter Plugging in the power doesn't appeal to me at all. I bought IM because I read that it performs well in the snow and the Prius does not, but I believe that the latest model has some AWD as an option. If it is available in 2018, I will be satisfied with the Prius of DD. I don't want to be bound by anything, let alone every night.

Vampire loss in the battery seems to be Tesla's domain-for example, the sentinel mode (recorded by a security camera) is very power hungry.

But my previous 12 Leaf and current 19 Ioniq won't lose much even if they are parked for a few days in a cold environment.

Whether it is parking or driving, the additional electronic equipment of the car is an additional drainage problem, which is a good point. I'm sure it will be tracked somewhere, but if the design/battery series has a similar product cycle to the current model's software, and O/S changes may consume more energy than the original hardware specifications. Similar to an old laptop with a new factory battery, the way it consumes is different in the updated operating system/updated software version.

Since Tesla is the leader, I think other brands will eventually adopt some of its technologies or similar technologies, and at some point they will have slight power resistance.

I want BEV to have a "true range" display option. Tesla in particular has done too much in terms of safety margins. When my IP shows 0%, I want it to die.

They are getting better and better. My Ioniq has a very accurate battery fuel gauge. I ran it to turtle mode twice, and when it happened, the display was blank. That is distressing.

From what I've read, turtle mode means you only have about a mile or two left, and I just drove about 3/4 mile like this.

Due to various technical reasons, it is very difficult to monitor lithium-ion battery fuel. Surprisingly, it is so good.

"When my IP is 0%, I want it to die"

Isn't the reason they don't do this because it is often close to 0%, which is harmful to the battery? When the battery pack has 10% left, it makes people think that their juice is running out, rather than educating them to charge them properly to extend their life.

@jack4x: It depends on the battery chemistry and manufacturer. There are no hard percentage numbers. In some next-generation chemicals, such as CATL's sodium ion, they don't even need battery management, and you can reduce the power to 0% as you like. However, with current lithium-ion batteries, if you have multiple cars with different optimal low charging points, then trying to remember the appropriate low percentage for a particular battery will be a pain.

According to my own experience, in 7 years of EV driving, I have only 3 times with less than 10% indicated battery level. Now I mainly work remotely, and I only use a few kilowatts each time I travel.

"Vampire loss in batteries seems to be Tesla's domain"

That must be all the espionage activities that Tesla did for the US government with those "peripheral" cameras.

"Report: The Chinese military prohibits Tesla vehicles from entering the factory, by Matt Posky on March 19, 2021"

As the former owner of the B5 Passat, I had a long, warm and fuzzy relationship with the project before.

I miss it a bit.

Without spare ignition coils and old laptops and VAG-COM cables in the trunk, no suitable B5 owner can go further than a grocery store.

I recommend an annual subscription to allow the manufacturer to monitor your vehicle and notify you of problems. If you take your vehicle to an authorized dealer for repairs, you will get a 10% discount. :p

My CEL is very smart. It can emit yellow or red light. Yellow means you are messed up. Red means you were screwed up 100 miles ago.

Mine alternates between yellow and not bright at all. I heard that either the fuel tank cap is broken, the weather (probably!), the sensor in the fuel tank or the sensor in the engine.

No one can explain why it glows sometimes and sometimes it doesn't. It's so funny.

Putting a little tape on the lamp will fix it.

If it is a few weeks and then closed, I am not worried.

"That's because if the customer pays for the work, the money spent on labor will go to the dealer, not the OEM. If it is the warranty work, it will cost the OEM's money."

The warranty repair costs paid by the manufacturer are much lower than the retail price. They joined hands with the dealer to deny the warranty claim, attribute the blame to the customer and refuse to repair. Although online car owners forums are flooded with similar complaints, the dealer may say that the problem is normal, he can't replicate it, no one else has complained, or band-aid before the warranty expires, and then magically find a solution and ask for payment.

Dealers are the biggest criminals in the industry, followed by car manufacturers. I will buy it without a warranty and remove enough from the top. They had to invest zero dollars in the last five new cars I bought due to my normal maintenance, correct purchase, self-repair or ignorance of minor issues, or rejection of warranty claims. I would rather they never do it after the sale.

"The warranty repair costs paid by the manufacturer are much lower than the retail price. They joined hands with the distributor to deny the warranty claim, blame the customer on the customer and refuse to repair"

I hear this all the time, especially about Hyundai, but I own Sonata and Genesis, and have not *one time* encountered a delay in warranty repairs, or even vague repairs. Now I’m renting it for free, while Hyundai Motor is waiting to be able to make an ECU for my Genesis. They pay 90% of the multi-K bill, even if the car is out of warranty when the problem occurs.

Maybe I'm just very charming.

Someone told me that a flickering CEL is more serious than a stable CEL. My 1998 Subaru CEL is often opened. Each time, the fault was the low efficiency of the first-row catalytic converter. This is not surprising, because the car is old.

The independent store I visited read and cleared several errors for me, and then suggested that I let my readers do it myself. This will work for the rest of Subaru's life. I still have a reader, and now using it on my 14-year-old Infiniti, it started to throw the same code.

Great article. The true story was obscured...the dealer accessed the vehicle remotely. This should cause fear in people's hearts. Is this limited to news vehicles or can they do this on any vehicle?

As for checking the engine lights, I read them as not checking the engine. Unless the car rattles, shakes, or emits black smoke, I don't care. Usually nonsense related to emissions. If you are unwilling to let me know what the problem is, please don't expect me to waste time or money on the idiot lamp.

Reading the code does not necessarily tell you the problem, but you can start troubleshooting. Some obvious problems will not throw out the code, such as speed stagnation (which actually helps emissions), so it may involve some guesswork, starting with the simplest and cheapest potential fix, unless it’s the dealer (guessing) and you It is a cash customer.

A few years ago in central Nevada, my 2000 Toyota Corolla engine inspection light turned on. To make sure this is not a serious problem, I stopped in Winnemucca and found an auto mechanic. He told me that they have no way to diagnose it, but as long as they stop at any parts store, they can run the diagnostic program for free. I went to an O'Reilly's. They told me that it was an intake sensor and asked me if I wanted to clear the code. I chose to clear the code. During my next journey, the lights came on intermittently. When I got home, I changed the sensor.

A friend of mine chose to ignore the inspection engine lights on his Ranger in the early 90s. The problem with its signal eventually blocked his catalytic converter. In rural Colorado, where there is no emission inspection, he just took down the catalytic converter. You really don't want to be by his side when his car is driving, and I don't want to follow him on the highway on a sunny day. The exhaust is incredibly spicy and foul.

I like CEL best. This is a notification to insert a barcode reader and check the health of the engine. Mine is in V due to evaporation system problem (charcoal filter). I don't like it because, in addition to the flashing pattern of misfire, it can hide subsequent problems that have appeared since they were first triggered by the original problem.

tl;dr Buy a barcode reader.

I changed the oil for my son's car a few days ago (2006 Malibu 3.5L V6, it burns some oil, so it needs to be refueled regularly). I was talking with my spouse and discussing dry start (after oil change) and unique noise (which of course will disappear) as well as oil pressure lamp and inspection engine light. The following problems occurred:

If you keep driving this car and never refuel: A) When does the oil pressure light come on? (Remember that its pressure is not level) [How much damage has been caused at this point? ] B) Check when does the engine light come on? (Assuming there are no other problems with the vehicle.) [Will it be "too late" then? ]

This is a fairly old design and low compression engine. As long as there is enough oil to generate pressure, it can operate almost without oil. During the oil change, there is still an oil film on all relevant parts, so as long as there is enough oil in the oil pan to allow the suction pipe to reach and pump the tappet. Obviously, the oil pressure sensor is in the most important place. When the oil pressure lamp is on, it will not cause damage-this is a preventive warning. The imminent seizure may trigger CEL, but it did not happen on my wife's 2013 Equinox: power failure; shaking; then blowing out all the oil on the timing side. I don't know that 2.4L POS is an interference engine. This is a cancellation, just a few months after the warranty expires.

If we Americans just ask us to go back to the carburetor on the pickup truck, we will have a better life. Give me a good American pickup truck, without all plastic, 4 barrels of carbohydrates, no catalytic converter, capable of running leaded fuel, and you can drive back 0.10 or better but 0.15 under its legal restrictions

In addition, Jesus wants us to have 1.00 petrol

If God doesn't want us Americans to drive under the influence of alcohol, he won't give us pickup beds and let us throw the empty ones in.

Carburettor, manual choke door, mechanical ignition point, crank window, manual door lock, ability to start the vehicle in gear, fuel tank behind the seat, 4-speed manual gear, long gear shifting during gear shifting will allow you to enter different Time zone, 2-speed and 3-speed automatic transmissions, three on the tree, manual heater control...

It's easy. Republicans should be blamed for this. They just want people to be ignorant and/or misled. Well, seriously, how can you expect car companies to let customers know what happened to their cars? Less information == fewer lawsuits. Imagine that a customer knows the error code and tries to repair the car and is injured, and then file a lawsuit against the car manufacturer.

If Republicans’ vehicles still had 4 barrels of carburetors, no catalytic converters, and no airbags, they wouldn’t even have padded dashboards or seat belts.

Because I am a supporter of xxxxx, it is best not to wear a seat belt so that when you drive a pickup truck home from the bar, you can get rid of the wreckage.

But the reason for your crash is never because of drunk driving, but because it would be better to drive like that. The accident was caused by the slippery road surface, which caused the Democratic Party's tree protectors not to use enough road salt.

Mercedes provided fuel injection and ABS in the 1970s, and airbags since 1980. Regardless of political affiliation, the industry is moving in this direction. Not to mention that Nixon signed NEPA in 1970, but who needs the facts?

https://media.daimler.com/marsMediaSite/en/instance/ko/40-years-ago-Mercedes-Benz-launched-the-drivers-airbag-and-seat-belt-tensioner-in-series-production. xhtml?oid=48190741

Speaking of airbags, Ronnie made an interesting article about their history at my request a few years ago:

https://www.thetruthaboutcars.com/2014/06/automotive-archaeology-where-eaton-crash-tested-the-first-practical-airbags/

Mercedes is moving in this direction, and many others are also moving in this direction. General Motors had airbags in 1973. In fact, dinosaur automakers were still producing carburetor cars in the early 1990s.

Automakers struggle with airbags. Remember their ridiculous seat belt iterations as passive restraints before the advent of airbags?

So stop talking, you are talking about a company like Mercedes, you can buy some American cars (truck) without headrests in the 90s.

Although lobbyists hired by a certain political party and the Big Three exerted certain pressure, the government still enforced these things.

What does this have to do with my comment? anything?

This is related to your comment because you mentioned Republicans jokingly. I use this as a basis.

This is a joke. I love the Republican Party.

It's time to take out the user manual, any user manual and read about the subject. Many cars will indeed tell you if this is a fuel cap problem and are equipped with separate lights for this. Otherwise, as you will find in every manual, I have checked whether the light on the drive is on, so no immediate attention is needed. If it is flashing, pull over as soon as possible, because if you continue to operate the vehicle in the current state, it may cause damage.

Stability and flicker are part of the OBD-II specification, but 99% of people don’t know it because they are not automotive professionals and they never bother to read that part of the user manual.

There is no need to do anything beyond the CEL, and it is useless for 99% of drivers, except for the upper limit of inspection warnings purely to save manufacturers and dealers money. They really don't want to educate people that they need to put on the hat again and tighten it up. Of course, for this reason, some manufacturers have used capless fillers, mainly not for the convenience of customers, they tout it as.

If people really care why it’s turned on, they might be able to use Google and find out how cheap the Bluetooth dongle and basic applications are, and decide whether they have the ability to know why it’s worth $20.

In fact, if you really think that you are a car lover, then you should at least have the most basic dongle and applications.

I personally have a few choices. Several cheap Bluetooth Amazon specials, a more expensive Bluetooth unit, it can also automatically perform a medium-speed CAN bus and a hard-wired version, it can also use HS and MS CAN when changing settings, for example to illustrate changes in tires Diameter and tire pressure caused by changes in the rated load of the tire or adjustment of the temperature setting of the heated steering wheel.

Hello Gang, I will comment every day, but only in rare cases, but I hope to do more soon. You all overlooked the elephant in the room-the dealer hall is not interested in making it easy for DIY or local oil monkeys to do this. OBDII's code reader, even with advanced features, is less than $100. This computing power is present in every new car or recently manufactured car. Repairs, whether real or imagined, are a cash cow.

One reason why CEL didn't tell you what went wrong is that even the computer and its code may not know it.

The only CEL I got in the 05 Scion xB is equipped with traction control lights and anti-skid control lights. CEL code is used for something obscure. This happens intermittently within a few months.

Applying some of my work experience and the data from the scanner, it turns out that the *trailing* O2 sensor is broken. The $75 parts repaired everything.

Counterpoint. The OBD-II diagnostic system is very useful, and it is very useful for anyone who wants to know about it. If not, take it to the garage; you may not be interested in cars, or have no talent for maintenance or repair. First, the terminology. The industry abbreviation for this lamp is MIL, *not* CEL. That represents a fault indicator. The data port usually located under the lower edge of the driver's side instrument panel is ALDL: Assembly Line Diagnostic Link. In OBD-I cars, the data port of some cars (for example, Ford or Toyota) is located in the engine compartment. As a teenager in the 1980s, I regularly check whether my parents' cars have fault codes. In GM, you insert a customized key, paper clip, or jumper between the A and B terminals of the rectangular data port, then turn on the power of the car and count the number of flashes and pauses. 1-2, 1-2, 1-2 indicate the end of the sequence, if no other numbers are specified, all will be cleared. In Chrysler, you quickly turn the car on and off 3 times, then turn it on, and the "Power Off" light will flash with a number. Toyota, find the data plug under the hood, short the terminal E1 to TE1, turn on the car, and the number flashes. Other manufacturers are similar. When transitioning to OBD-II in 1996, the rounded trapezoid ALDL was standardized globally, even though the software and some code definitions differed by manufacturer and continent. The code of P0### is universal, while the code of P1### is manufacturer-specific. Note: If you are buying a 1994 or 1995 GM product, please check if it has an older rectangular ALDL and avoid using them. They are missing a contact on the B pin. General Motors began to equip some of its high-end models with OBD-II in 1994. For this reason, the EPA exempted them from providing user/owner-readable interfaces on other models. In the OBD-I era, I worked in the field of auto parts for several years. In the early 00s, in the current OBD-II era, I worked in the field of auto parts for several years. Early Ford codes almost always blocked the EGR valve due to carbon. GM usually throws out codes for O2 sensor failure. There are only dozens of possible codes in OBD-I cars, while there are thousands in OBD-II systems. The OBD-II fault code provides a good start for you to solve the problem. It may not be as simple as replacing the sensor or component that reports abnormal parameters. I remember a Grand Am with a MAP code (Absolute Manifold Pressure). So I ordered a MAP sensor for my child. A few days later, when he came to pick it up, I went to the car with him to show its location and how to change it. It turns out that there is a hole in the tube that powers the sensor. I went in and cut a few inches of pipe, gave it to him for free, and returned the parts. Another time, a man driving a new Buick LeSabre had an EVAP code. We checked the fuel tank cap, erased the password, and I told him to return the car to me if the MIL returned. He was there the next day and said that the lights were on and the car had a breakdown, which is incredible on the 3800 which was only a few years old! The code showed 2 cylinders, front and middle, but he didn't know how to remove the hood for visual inspection. Twist the oil pipe and lift the lid to reveal a large insulating ball. The mouse nest is there. The mouse has eaten the injector wire of the No. 2 cylinder. The man brushed off all the debris, screwed the bare end of the wire back together, and was soon on the road. Never saw him again. A local banker brought me her Chrysler van, and she was driving hard on her way home from a nearby town, with a *flashing* MIL. The two cylinders reporting misfires are clearly consistent with the numbers on the central coil of the coil assembly. She was reluctant to buy a $51 product, but I showed her how her husband removed the plug wire in a few minutes and replaced the entire coil assembly with 4 bolts. The problem is solved, she may save hundreds of dollars. I used to carry an expensive barcode reader for my own car and a friend's car, but it may have been 10 to 12 years since I gave up on it. I plugged a $12 ELM-327 Bluetooth dongle (Google it, they are cheap and ubiquitous) into the ALDL of my GMC, and I can access it at any time using the Torque Pro app for $4.99, whether it’s a fault code or Real-time data. I can easily take out the ELM-327 and extract the code from other cars. I often do this for my friends. It is difficult to know if there is something as simple as a thermostat stuck on a pre-computerized car, but a fault code indicating that the engine temperature is lower than expected will tell you exactly where it started. A friend recently replaced the battery in her Lotus Elise. Because she didn't know to back up the power supply, each computer module lost communication, causing the MIL to light up and fail the inspection. She searched the Lotus forums, but only found the owner of the new computer shipped across the country. Others claim that only Lotus dealers, not Toyota dealers, can refresh their computers. I did an in-depth research and found an owner with the correct 2-digit code sequence. I found an application that can write to the car through ELM-327 (can't remember the name of the application at hand). A few weeks later, she entered the sequence through her mobile phone, and the problem was solved. There was no charge except to spend a little time finding the correct information. So I disagree with the usefulness of MIL. I can associate hundreds of cases to illustrate the lighting of the warning light and the generated code to lead me directly to the solution. I do understand that simple lights cannot provide good information to the driver. I will support displaying messages in simple language to summarize the problem. In my opinion, the industry has pulled a fast in MIL’s popular "Check Engine" tab, because most of the fault codes are related to auxiliary systems, rather than actual reciprocating engine components. The warning light should simply or graphically convey "fault detected".

In detail, the 1994/1995 GM system you mentioned is called OBD 1.5. And, you are right-although it uses an OBD 2-style data port, it is not OBD 2, and you need a completely different code reader to use it. A member of my family has a 1995 Buick Riviera. Oops.

Thank you for your detailed explanation, I forgot the name (number) of the transition!

@80凯迪拉克; thank you very much for posting. It may be more information than I deal with at one time, but I will copy, print and keep it for future reference.

In general, anything that is complicated enough to be diagnosed at the same time has fundamental errors, and lacks a simple and reliable way to connect to a general-purpose terminal and get shell prompts.

For the author-buy the scanning tool for $40. The problem is solved

That is simple and cheap.

The OBD agreement was prepared by the committee and enshrined in federal law. In this case, all complaints are verified and understood. As long as the current behavior of the system remains the same as required by law, automakers are free to independently make existing agreements more useful, more accessible, and beyond their current behavior.

One of the stupidest reasons to check engine lights is to forget to tighten the fuel tank cap. I once encountered this problem on my Infiniti G35, and a friend of mine recently encountered the same problem on his Toyota Camry. For all onboard computers and monitors, how complicated it is to flash a message saying "Please try to tighten the fuel tank cap".

This is why the gas cap will click (my understanding). Example user manual wording: "Reinstall the cover by turning clockwise until it clicks."

TTAC survey: When properly tightened, how many licensed U.S. drivers are aware of their throttle clicking? (My guess is: 38%. I will listen next time I go to the gas station.)

(A friend in the family, when her car needs gasoline, she texts her husband. Very good system-for her. My family will not use this system.)

Get a Ford with Easy Fuel®: https://youtu.be/i2k1281Nb-I

(Wait 5 seconds before removing the nozzle. Ford says this will prevent dripping.)

My truck has a self-sealing cover. This summer, it is throwing out the message of "checking the fuel port" and then stopping on its own. This thing started again this week. I ignored the PIA. The truck is running well.

Not many manufacturers have check air cap lights or warnings in the message center. This is done because the dealer has too many cars under warranty, and they just didn't tighten the throttle before making a click.

The car is either new enough to be under warranty, or old enough to be documented.

> US$40 handheld scanner or US$7 OBDII Bluetooth/wifi dongle>Scan the code and search Google>If available, use the service manual for troubleshooting steps

If you are too lazy to follow this simple process, then you may not care about the car and should pay the dealer their due share.

It has been a few years, but if I remember correctly, "check engine light" "turn on" will cause the emissions test required by Ontario to automatically fail.

This has always been my general understanding. This is why I was shocked when my daughter's jeep passed the emission inspection with the lights on.

(When we purchased her vehicle, it had a problem and it took some time to track it up. The vehicle cannot be registered without an emission certificate. The county clerk's office told me to pass the test again to remain legal, and the clock is under repair. Drive through Checked the channel and explained that I was about to fail-MIL is solid. Passed the OBD-II interface emission "test" and obtained a cleaning certificate from the worker, he now thinks I may be a mentally unsound person. Confusing.)

I have a Mercedes GLC 300 that is less than 10K miles away. CEL appeared three weeks ago. Now that it is within the warranty period, it will be returned to the dealer. This is a malfunction of the evaporator, but you should see a checklist they must check to track down the problem. Obviously, there is also some kind of pump in the evaporative removal system. What I learned: I don't want another ICE car. Even with a code reader, there are still too many problems to be solved, and my old technology is just continuous replacement parts (still cheaper than the dealer) too many these days.

The thing you are talking about is now available on the plane. For an example, see Airbus ECAM. If the system on the aircraft fails, there are 2 indicator lights, one for lower priority and one for higher priority, respectively amber and red.

Once triggered, the aircraft will display text on the nature of the fault and how to deal with it on the multi-function display. It can even tell you which other systems are affected by the failure.

If Airbus has been able to do this since the 1980s, then I believe that today's automakers can also do it. Especially because almost all cars have built-in displays. Oops, it doesn't even have to appear on the screen in front of you with an alert. Keep CEL, when activated, a selectable notification point will appear in the on-screen menu. If a clueless driver gets the light and does not want to dig deeper, then nothing changes. If anyone with mechanical knowledge wants to learn more, then it is there.

It sounds like it's time to write an article about scanning tool recommendations. A few years ago, I connected a ScanGuage so that I could monitor fuel mileage (yes, I am the one who tracks the mileage of every car he drives). ScanGuage has typical error bars, so the numbers I calculate are usually different, but I think if they are within a reasonable percentage of the expected mileage, I am gold.

Later, the same ScanGuage was connected to another car-also mainly to monitor mileage and show the coolant temperature rise. My car does not have a thermometer, only a fake light. I think ScanGuage saved my back in the new car I had at the time... To make a long story short, someone rear-ends and knocks me down, loosening the sensor and causing the thermostat to not work properly. I don't know.

Fast forward to now, I have a cheap scanning tool, but I am scared to use it. When Scotty Kilmer had one of his many clickbait videos, I watched it everywhere on YouTube, YMMV. "Using a certain type of scanner will burn your engine" or some other similar explanation. Of course, the video will not enter the scanning tool that may cause the problem, and I don't know how it happened.

In any case, it seems that the recommended scanning tool posts may be in order.

To be honest, most of these cars have USB inputs.

These cars should be able to download the diagnostic log directly to a USB flash drive.

I remember when CEL was called "idiot lamp"

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