Idiot light or check engine lights on modern cars

[zman]

I have never owned a car with these modern features but see some for sale that are priced cheap and have some code or light on and the price is half of the market value sometimes even less, usually says wont pass emissions beacause of the light.
Question is are these cars something to avoid? It would seem to me anything could be repaired if you know what part it is, maybe there are parts that are impossible to find?..Too expensive?
Wondering why these people don't fix these cars and sell them for market value instead of losing money.

 

[mcgovern61]

An example;

Our 2002 Hyundai Elantra check engine light goes on for all kinds of things, some minor, some major. One time it went on for something as simple as the gas cap was not on. Next time, it was actually a failure of the gas tank vapor recirculating system(?). Cost me well over $500 to replace the components. Other times it is just an oxygen sensor.

Any of the items can be fixed. Depends on what else may need to be repaired and the total cost. For me, we could not afford to replace an otherwise running vehicle and it was worth the $500 to repair (and pass NJ Inspection). 3 years later and the car has more than 150,000 miles on it running like a clock.

 

[slabghost]

No inspection required here in Ohio. I've driven quite a few for years with that stupid light on.

 

[zman]

Gerry, is that $500 plus to take it to a shop or is the part $500? couldn't a code reader be used to find out what part and do it yourself?

 

[slabghost]

AutoZone will read codes if you ask. They'll be happy to sell you parts too.

 

[dan filipi]

That's the thing, many times the trouble code doesn't tell you the exact part needing replaced so it's replace parts until trouble is gone but a trouble code can be as simple as a 'misfire' and changing plugs and wires will fix it.

 

[zman]

dan filipi » Wed May 06, 2015 7:16 am[/url]":367qslwl]
That's the thing, many times the trouble code doesn't tell you the exact part needing replaced so it's replace parts until trouble is gone but a trouble code can be as simple as a 'misfire' and changing plugs and wires will fix it.

I have heard of that. If you type in a trouble code there are plenty of answers on google, just wondering if there are truly hot potatoes out there.
The reason I ask is I have 5 sisters and nieces,nephews,and their husbands and all don't know cars and sometimes look to me for answers. I don't own or need a code reader but always thought it would be a handy tool to own.

 

[Omega Man]

Lol, the problem is often a loose or broken gas cap.

 

[AApple]

Some folks just don't have the $$$ to "fix" a check engine light issue...just depends on what the issue IS. Some folks just don't wanna mess with them, either...easier to sell it and be done.
Most later model cars will turn on the check engine light for some of the silliest problems...such as the gas cap/oil filler cap loose, low coolant/engine oil, or even a speedo problem. The systems in late model cars can be a major pita to repair, and that's after FINDING what the actual problem is. Sometimes, the diagnostic time costs more than the actual repair. Loose/corroded grounds and power circuits can cause all sorts of electronic gremlins to rear their ugly heads. Some folks may think they have a major computer problem, when they may only have a loose wire. Then, you have some shady shops, or shops that don't have the qualified techs to diagnose the problems, and you wind up buying several hundreds/thousands of dollars worth of parts that still don't "fix" the problem. After getting the shaft a few times, some people will decide it's better to get rid of the vehicle, and let it be someone elses problem.
A major repair can cost thousands. A trans repair in a late model BMW can cost over $12,000. Computer programing/updating can add to the costs, and most later model cars will require that service if replacing/repairing any of the major components....or even the stereo.

The best advice is to have a qualified tech check the vehicle over really well before buying used, especially if the price is well under market value. :yes:

 

[slabghost]

I prefer to buy and fix older vehicles that do not have all sensors bells and whistles.

 

[mcgovern61]

zman » Wed May 06, 2015 9:11 am[/url]":39yexozu]
Gerry, is that $500 plus to take it to a shop or is the part $500? couldn't a code reader be used to find out what part and do it yourself?

That was $500 for the entire job, parts included. What Joel posted is correct! Whenever I take a car in for repair, I always make the shop show me the issue physically. You might be surprised how fast some shops change their story when asked to see the defective part(s) and ask for an explanation of what failed. I do not mean to disparage any shop or mechanic, but we have had way too many "repairs" proposed for parts that did not need replacement with shops that were more or less just parts changers hoping to find out what was wrong at my expense.

I really do not mind paying a shop for diagnostic work if they can prove the problem and explain what happened. I have a local Pep Boys that actually has some great diagnosticians! I also have only 1 Hyundai dealer that can do great diagnostic work, but their overall prices are too high.

My Ford's on the other hand seem to run by themselves! :yes:

 

[Mad Dog Tannen]

Auto zone will not read codes in California anymore. But codes only tell you if the sensor is bad or it's reading out of limits. It basically shows you where to start looking and narrows it down. But you still have to do some troubleshooting in most cases. So a check engine light v=could be very simple and cheap or very expensive and complex to fix. It really depends on the code and why it's reading out of limits.

You can Google the codes and they have charts to see what they are for online.

 

[Tom_Charlton]

I have a code reader. It helps to narrow the search for what's wrong, but doesn't always give enough detail to fix the problem.

 

[AApple]

There's a big difference between a code reader, and a scanner. Code readers will only get the codes stored in the E/PCM, and possibly a description of the code, which is a good start to point ya in the direction ya need to go in for diagnosis. BUT...a code can be set for one component/function that is actually caused by something totally different. A vacuum leak can set O2 sensor codes...replacing the O2 sensor ain't gunna fix that. A scanner will give you live data, and will also have the ability to read a stored "movie", or data reference from the E/PCM that will give you info on what happened at the time to set the code. It's then up to the diagnostician to go thru that data and determine where the actual fault is/was. Believe it or not, a seat belt code on a late model Volkswagen will effect the transmission. A radio issue on some Fords will mess with the speedo-cruise control. A bad diode in an alternator will put out uncontrolled RFI that will cause shifting problems, and set engine related codes that will have ya troubleshooting for days.

And THIS is why folks elect to sell their vehicles rather than repair them. Then again, in some areas, a newer car with a low sales price could also mean it has flood damage...and the ensuing electrical problems(and smells) that come along with it... :builder:

 

[Ansimp]

I prefer to reset the check engine light with a cheap scan tool or my iPhone/iPad with an app and a wifi obd connector. The advantage of the app is there are different ones available and most update regularly for free once you have purchased the app. I now use my iPhone/iPad as A Dashcam, Google maps GPS, Sygic GPS ( stand alone), GoPro remote, Trip planner, scan tool , camera / video and I even make calls sometimes :yes:
You can buy cheap scan tools now as well and I reconmend them for anyone who wants to work or buy later model cars. As Joel said it is not a magic fix and lots of expensive diagnostic machines cannot do all functions of an oem service tool and sometimes you have to spend the money at a dealer. My wife and I reset service codes on her diesel Forester for almost 12 months until I finally changed the DPF and a faulty glow plug. In tracking down the DPF problem I had to use a live data diagnostic machine to see that a DPF burn was being done about every 25 miles instead of 200+ miles. On the dealer only stuff I had my Subaru dealer install for $66 aud the new ECU software that made our 2010 run like a 2014, the best money I have ever spend on any vehicle :yahoo:

 

[zman]

Well that was educational, seems the code reader isn't the end all be all but the scanner is better and even still it comes down to good ol under hood detective work, unfortunately there are so many items in so many locations that effect so many things.
Really is a shame, Not sure why but MPG hasn't changed a heck of a lot, HP is higher so they are squeezing more HP out of the same engines that get the same mileage as the old engines.
I`ll keep buying old cars and continue sending family members cars to the shop should they get a light that isn't a cap or low fluids.
One said she has a check engine(Toyota) and just turned around 100K , I said it is probably a 100K service that automatically lights up and needs re set. Couldn't see anything obvious and it runs good.

 

[Ansimp]

zman » Fri May 08, 2015 1:04 am[/url]":xhgrogsk]
Well that was educational, seems the code reader isn't the end all be all but the scanner is better and even still it comes down to good ol under hood detective work, unfortunately there are so many items in so many locations that effect so many things.
Really is a shame, Not sure why but MPG hasn't changed a heck of a lot, HP is higher so they are squeezing more HP out of the same engines that get the same mileage as the old engines.
I`ll keep buying old cars and continue sending family members cars to the shop should they get a light that isn't a cap or low fluids.
One said she has a check engine(Toyota) and just turned around 100K , I said it is probably a 100K service that automatically lights up and needs re set. Couldn't see anything obvious and it runs good.

Make sure it is not a timing belt minder light as we all know what can happen when you don't change them when you are supposed to

 

[zman]

Ansimp » Thu May 07, 2015 2:12 pm[/url]":1ixieysw]

zman » Fri May 08, 2015 1:04 am[/url]":1ixieysw]
Well that was educational, seems the code reader isn't the end all be all but the scanner is better and even still it comes down to good ol under hood detective work, unfortunately there are so many items in so many locations that effect so many things.
Really is a shame, Not sure why but MPG hasn't changed a heck of a lot, HP is higher so they are squeezing more HP out of the same engines that get the same mileage as the old engines.
I`ll keep buying old cars and continue sending family members cars to the shop should they get a light that isn't a cap or low fluids.
One said she has a check engine(Toyota) and just turned around 100K , I said it is probably a 100K service that automatically lights up and needs re set. Couldn't see anything obvious and it runs good.

Make sure it is not a timing belt minder light as we all know what can happen when you don't change them when you are supposed to

Thanks, timing belt was done not long ago, just need to reset it if that is the trouble. I probably shouldn't get involved.