Here’s Why The Check Engine Light Is A Horrible, Terrible Thing

Jalopnik ^ | 24 Nov 2014 | Doug DeMuro

[Eric Pode of Croydon]

It happened on Thursday night. I went out to my car. I climbed inside. I turned the key in the ignition. And

[Kackikat]

Yep

[SoCal Pubbie]

It takes a bit to get the hang of it but it works on my cars. Do a web search and you’ll find videos showing how to do it.

[right way right]

That is because the computer has the ability to learn parameters to deal with small changes in what it sees and makes adjustments so that engind still runs and improves over a bit of time. (I can't remember the term but a computer guy would know it)
All an engine light is, is and indicator of a parameter change.
Engine lights are properly called MIL or Malfunction Indicator Light.
Most cars today have a computer that operates the engine as well as the trans and often has sensors in other drive components too PCM all in one unit. (powertrain control module)
All these systems have been more and more consolidated through the years and the systems more reliable and easier to troubleshoot for mechanics.
Any good shop has thousands of dollars in scanner tools and software to
read what a cars computer sees.
Typical 20k plus for the average shop. Last shop I worked had about 90k
in.several scanners because they worked on all things, Yugos to semi trucks.

Key word “for mechanics”.

[right way right]

A scanner is not a code reader but it can read codes and a lot more.
A scanner can read and display parameters visually and can capture abnormalties in parameters and even take “snap shots”.
A scanner can also overide the computer to do tests.

[Polynikes]

“My Highlander did the loose gascap thing to me once! My mechanic plugged in his tester and told me to tighten the cap.”

My son got worried and called me when his Honda did the same thing. I asked him if had gotten gas recently. Sure did. Had him just take off the gas cap and put back on firmly. Voila no more light.

I also had a Nissan 4x4 have an O2 sensor light come on. Couldn't get it smogged with that light on. Would have to have taken it into a dealership for XXX 100’s of dollars to be diagnosed/fixed. What made me suspicious that this was a engineered scam for the dealers was the light came on exactly as I registered 30K on the odometer.

I pulled a wiring diagram for the truck and found an access port that could be popped out giving me access to the O2 sensor wiring. Found a small tag on a connector that said “reset alarm at 30K disconnect at 60”. I opened the connector and no more light and the truck smogged and ran A-ok. Just was a design scam built into the truck.

[WhirlwindAttack]

Pull the bulb for the light.

[wally_bert]

I have a 1965 Willys Jeep that I am off and on working with. Every rattle or problem I fix or patch results in a couple more it seems.

I put a new one barrel on it at that helped a lot but it’s got very audible valve problems with #1 cylinder. The others compress test OK. It smokes some and I’m sure annoys the commies next door so it isn’t a total loss.

If anyone wants some laughs, watch and listen.

http://tysonneil.smugmug.com/Cars/1968-Project-Willys-CJ5/i-7DQZ96V

Mine is some kind of oddball in some respects. I think it has some M38 in it. One thing I don’t ever recall seeing on an old model vehicle is a distributor with out a vacuum advance. It simply isn’t there.

I have an aftermarket distributor around that I bought for another long gone Willys. Maybe IF I can be left alone, dig it out and see if it will work.

The killer on the other one was someone had been in that engine before and the distributor and oil pump shaft were keyed one way but I couldn’t see the difference. It was 180 out. I have a feeling I may run into the same thing here.

I am going to have to farm out a rebuild sometime. It’s been decades and where I live and my home and work, not practical at all.

Maybe what time I get around Christmas I can tackle the worn steering box. There is a lot of death wobble. Tires are borderline junk too.

There is the CJ7 that I am finally getting more into and the old raggedy 79 K5 blazer that runs OK.

[wally_bert]

I don’t know myself. My old Blazer doesn’t have that problem since it predates ABS but it has plenty of others.

http://tysonneil.smugmug.com/Cars/Assorted-Cars-Trucks/i-SLBQcS3/A

I liked those years, got it for nothing, use it as a tractor and test bed for stuff and probably couldn’t get much for it.

[wally_bert]

The transfer case on my old blazer is stuck in low range and I haven’t gotten around to it. Just as well since it is a back building tractor. If someone bothered to steal it, a good jogger can keep up with it.

http://tysonneil.smugmug.com/Cars/Assorted-Cars-Trucks/i-SLBQcS3/A

[PLMerite]

My Hyundai sends me emails.

[cyclotic]

Sounds like my first car. Odometer and gas gauge both broke. Only ran out twice in two years. Headlight switch caught fire on the freeway. That was kind of exciting. Quick fix too.

My last car had black tape on some light or another for a couple years. Still ran.

I’ve never sold a car for more than $1,000. My son is driving my old car. 2001 Sable. He’ll hit 200K next week. I bought it seven years ago for $1500. Biggest repair was a transmission adjustment when my daughter drove it up Pikes Peak. She was so proud of herself as a newer driver. I wish she would have called me first so I could try to explain better gear usage. Oh well.

[M Kehoe]

Good evening.

It took me one week (with dealer help and reading the manual), to drive my vehicle. Damn thing communicates with me through various electronic/voice/touch methods. Reminds me of Christine.

Bad ass vehicle though...

5.56mm

[Protect the Bill of Rights]

Not rocket science. i can manually pull the codes from my xterra, get problem fixed & manually rest the codes. :). Can do it with son’s honda, too.
I know it works because i have not had any issue with passing emissions.

[sheana]

It really is a racket. Hubby says never again. No more Mercedes.

[Chickensoup]

OR...you can be like me. I have a 1969 VW beetle. I spent two years restoring this car. She and I are one. I can hear, feel, smell, and sense anything wrong with the car. No need for the idiot lights.

And unlike my ex-wife, she won’t leave me for another guy.
_____________

Unless he has a better key..... ba da boom!

[central_va]

You can probably go to Mexico City and buy a 12 year old VW bug, not the "new" one the original they made them in Mexico until just recently, for very few pesos...

"By 2002, over 21 million Type 1s had been produced, but by 2003, annual production had dropped to 30,000 from a peak of 1.3 million in 1971. VW announced the end of production in June 2003, citing decreasing demand, and the final original Type 1 VW Beetle (No. 21,529,464) rolled off the production line at Puebla, Mexico, on 30 July 2003,[46] 65 years after its original launch."

[NY.SS-Bar9]

Well then, if you have a laptop and a VW

Ross Tech Vag-Com

[Nateman]

I think you can OWN an OBD . If you are a business you can’t lend it. I can’t point you to the statue but I have experienced the problem first hand. The extreme example I can relate happened in Laughlin Nevada.It’s on the border with California. On the California side the Auto Zone could not lend me their OBD. So I drove to an Auto zone on the Nevada side where I was able to borrow it and then fix the problem myself. Try getting rid of used Anti-freeze in most states. That sucks too. I wonder how many people have dumped the stuff illegally because it is so difficult to do so legally.