venchka

I have noticed several posts from folks with new vehicles and their Check Engine Light coming on. The general response seems to be: I'll have it checked when I go in for Service A. This could be several thousand miles in the future. I was skeptical of these responses. Granted, the CEL is a very vague indication of real or not so real problems. Fortunately for us, Lisa views the CEL as a warning of impending DOOM!
Case in point:
Sunday before last we left the house headed for Houston, 250 miles away. The CEL came on. We got to the highway. Accelerated to speed and nothing awful happened. Drove to Houston. No problems. CEL still on. Monday I phoned Star Motors and made an appointment for Tuesday afternoon. CEL still on. Tuesday when I started the GLK to drive to the dealer, CEL was not on. Naturally. I tell the SA (recommended by a friend) about the CEL and also ask for the 5,000 mile tire Balance & Rotation. The CEL was in fact indicating a real problem: Intake manifold pressure sensing hose. They replaced the hose. R&B the tires-my nickel. Wash. Out the door 3 hours later right at closing time. They practically forced me to take a loaner. I declined as I had no place to go.
Kudos to my wife for insisting that I have the car checked out.
Moral of the story: Don't ignore the check engine light.

Wayne

dgiturbo

That sucks.. CEL under 5000 miles. I guess things happen. Hope it's the last and a one off experience.
Personally I never ignore the light either, and get the code repaired right away.

venchka

There are posts throughout this Forum where folks talk about CEL coming and going for weeks and/or "I will get it checked at Srvice A." Strange.
Could have been worse. Sudden Coil Death or even worse. The main point: There was no indication of anything wrong other than the CEL.

Wayne

PHML

Have it checked out...don't ignore it.

MBNA109

Good job Wayne.

venchka

Thanks.

Wayne

jonnyrt

Good call Wayne, any warning light is there for a reason and should not be ignored....unless you have an old hoopty with 400,000++ km and the dash lights up like a Christmas tree!

My folks purchased a brand new 2012 Mercedes R-Class 350 Bluetech. Literally within 2 weeks, the CEL light came. Similarily, they took it in and turns out was a faulty sensor on the exhaust manifold, easy warranty claim.

venchka

The Check Engine Light comes on for a reason.
Confession: We had to look in the book to know that it was the Check Engine Light.

Wayne

MBRedux

Check engine lights detect everything from the slightest hiccup to a major failure and everything in between. But they usually serve two purposes... to make those who are not in the know so paranoid they run it over to their dealer or nearest repair shop, and two, to tell you it's time to open your wallet once again, your car may need repair.

That said there are times the ECU will detect the smallest error and throw a code, like a small PO442 EVAP leak. (removing gas cap while engine running usually) This happens often and we just tell our clients that if the car appears to be operating normally fine the code will reset itself in a few days and go off, if it doesn't stop on in. But if the code is something serious like a PO0021 (crank position sensor failure), the engine would not run very well if at all.

So it's up to the owner who usually knows ho their car feels. It if feels wrong, take it in. If it feels great and everything is running normally, chances are the fault was minor and the code will probably reset and go away.

Just get one of these inexpensive code readers and find out how serious it is before you head over to the dealer.

venchka

While under warranty, there is but one answer.

Wayne

MBNA109

Speaketh Wayne. Amen!

NVGLK

My CEL also lighted last month on my 2011 GLK. The car is running fine but I took in right away and they found the thermostat got stuck. Repair is under warranty.

venchka

MBRedux,
We all appreciate your vast knowledge of all things auto related. However, the truth is that most of us would be lost with one of those fancy code readers. Nor would we have the parts handy to correct the malfunction. The truth is, for most of us, it is far easier and more efficient to let the dealers handle any glitches. My only nit pick is why aren't there messages on the dash to tell us why the CEL came on in the first place.

Wayne

MBRedux

Well that's where I disagree. By suggesting that everyone lacks the know-how is a little naive in my opinion. Please speak for yourself if that's the case. The mere fact that you are on this forum means you are at least interested in expanding your knowledge, if not, please sign off and refer to YOUR DEALER for everything FROM NOW ON!

However, for those who are interested in expanding their knowledge base, there is NO law that prevents you or anyone else from diagnosing and even repairing your own vehicle. The only things that may prevent this is the lack of time, or the will, and of course money.

As a rule of thumb for those like me, we always like to know what's exactly wrong with our cars BEFORE we hand them over to those whose only incentive is to take money, either from the manufacturer when its under warranty or from us when its not.

As far as this reader is concerned....


...it is simpler to use than the keyboard you are now typing on. There is a little plug under the left side of your dash, above the hood release that accepts the male end of the reader. Simply plug it in, start your engine and viola... the codes are scrolled automatically along with their explanations and definitions. Jot them down, stop the engine, and unplug the reader. Now if in doubt, at least you'll know if your dealer is honest or not when your car is in their hands. ... cost of the reader... under $100 bucks... peace of mind... PRICELESS!

venchka

OK. Clarification. Most is not everyone. We all have a certain amount of expertise when it comes to vehicles.
However, vehicles are becoming so complex that not even the manufacturer can explain everything that happens in one of their vehicles. The 2012 ML is a perfect example of M-B taking months to sort out teething problems with the new M-Class vehicles, both gas & diesel. Suffice to say that there are enough clueless service folks to make one wonder why we abandoned points & condensers & distributors.
This forum is full of threads that start off something like, "My CEL came on. Took the vehicle to the dealer. They are stumped." But that's a different story.

Wayne

hanli0315

I totally agree your philosophy there. I absolutely hate when there is, what's called in economics, "Information asymmetry" and the other party just uses that to rip you off. While one can't be an expert in everything, we can still choose to learn a little bit more in certain area (in this case, we are on a car forum, so go figures).

By the way, do you have a scanner to recommend? I know none of these scanners are going to be as comprehensive as DAS, but any better ones, say in the $100 range?

MBRedux

Link: http://www.amazon.com/gp/product/B00...ZAE709FZ4J3C6B

ble2716

Great scanner but still more than $100.

hanli0315

Thanks, will check it out.

n5160u

The sister in law called me one night to tell me her car quit on the way home. When I got to where she was stuck the smell of very hot engine parts could not be ignored. The engine had seized and the dip stick did not show any oil present.
I asked her if there was any warning light on before the engine quit running.
She pointed to the spot where the CEL was on the instrument panel.
I asked her when it turned on, and she told me it had been on for several days.
When I asked her why she had not checked with me when the light first came on, she said " But it was only a tiny little light"
This is the same sister in law who ran over a tire in the middle of the road in daylight destroying the alloy oil pan on the wife's car because the tire rim was higher up that the oil pan. My wife who was with her at the time said she would have gone around it but her sister froze and did not appear to know what to do and then proceeded to drive straight into it.