Hot - Free "Check-Engine Light" Diagnostic at Auto Zone

[Analog]

I stopped at Autozone and noticed a poster that advertised a free "check-engine light" diagnostic for your car. My wife's Pontiac Transport has had an intermittend check engine light for the past few weeks, which is annoying, but a hassle to take to the dealer or a repair shop which will charge you the minimum of 1 hour of labor (usually $40-70) just to see what code(s) is in the car's ECM [engine control module].

In the old days (pre '94), you could short two of the ALDL pins (serial connector under the dash), and then count the number of flashes on the "check-engine light" to determine what the problem was. I did this all the time with my '89 blazer and '88 "yellow" fiero. But after 1994, the auto companies have gone to what is called OBD II, which requires a special interface to download the codes. Not much help for my '96 Saturn or the afore mentioned van.

Anyhow, I would consider this a hot deal, since there is no obligation to buy anything from Autozone. You just stop in, and they plug in the unit and tell you what the problem is. Of course, they want to entice you to buy the parts from them, and I must admit, this is an excellent piece of customer service. Cheers.

 

[Emulex]

aldl was never serial, you can buy your own aldl interface for like $75-100 and use freeware or demo software to do the same.

Fortunately the VAG family uses iso TTL standard, so a simple TTL-RS232 max233 chip can do the translation. fun stuff to learn.

 

[Evadman]

Not to crap in your deal, but on GM ( and most american cars ) you can read the codes with a paperclip.

Still works on my '99 dodge.

 

[MrHans]

Originally posted by: Evadman
Not to crap in your deal, but on GM ( and most american cars ) you can read the codes with a paperclip.

Still works on my '99 dodge.

same trick as yellowfiero or different? details man, details!

 

[Analog]

Originally posted by: Evadman
Not to crap in your deal, but on GM ( and most american cars ) you can read the codes with a paperclip.

Still works on my '99 dodge.

Not at all, I'm trying to learn too! But in fact, I beg to differ. The paper clip is exactly what I described when I referred to shorting two pins together. This only works on pre OBD II vehicles (pre '94). Now I have no clue why your '99 dodge works that way, it shouldn't!!

Here is a quote from a mechanics web page describing what I am talking about:

"Here's a description for retrieving codes from a GM vehicle partially from the Westec Auto page, plus some stuff I added. This will not work on 1996 and later vehicles (which have an OBD II compliant engine management system), or on some 1994 and many 1995 vehicles (which may be completely or partially OBD II). For these vehicles, a scan tool is required to read codes. If you don't have one, you pretty much have to take it to a mechanic. "

How to use a paperclip

Hope this clears it up.

 

[Analog]

Here's more:

On most vehicles equipped with OBD II compliant engine management systems (1996 and later), the old manufacturer-specific way of checking codes generally won't work. For these vehicles, you will need a scan tool to read the codes, so unless you want to buy one, basically your only choice is to take the vehicle to a dealer or mechanic. (On Chrysler vehicles, you may still be able to use the old key on-off-on-off-on method to read codes, or so I have heard.) OBD II scan tools are different from other types, older scan tools will not work unless you can get an OBD II cartridge and cable to upgrade it.

(from before mentioned page)

 

[Vette73]

I am a mechanic and can tell you GM PRE. obd2 you could use a paperclip to get the engine codes(expect caddilac), but with OBD2 you need a scanner. One OBD2 scanner will do all new cars as OBD2 is a Fed. Goverment requirment.

But Autozone will check OBD2 codes for free and try to help on OBD1 systems, but some Jap. and Europe cars need a special scanner as there were no rules for OBD1 systems.


So no matter what car you drive, american, Jap, or Euro) if it uses OBD2 then autozone can pull the codes for you, for free.

 

[Analog]

So no matter what car you drive, american, Jap, or Euro) if it uses OBD2 then autozone can pull the codes for you, for free.

Thanks Marlin, so would you say this is a good deal????

 

[NogginBoink]

Originally posted by: yellowfiero
Here's more:

....(On Chrysler vehicles, you may still be able to use the old key on-off-on-off-on method to read codes, or so I have heard.)

True. On my 95 Chrysler LeBaron, turning the key on-off-on-off-on-off-on-off-on (that's on 5 times), the "check engine" light will blink codes at you. Of course, you still need the book to look up the meaning of the codes.

Found a broken vacuum hose in my PCV valve that way. ~$2 for a replacement hose beats the dealer charge to do the diagnostics.

But... this is a great thread, and thanks. AutoZone might have a new customer next time my car starts yelling at me with that little light.

 

[Sesopedalian]

Very hot deal. If you have a light on, it's a $100.00 hot deal in this neck of the woods. There was a deal on a OBD2 scanner here a while back. If I hadn't cleared my check engine light I would be all over this.

 

[Vette73]

Originally posted by: Sesopedalian
Very hot deal. If you have a light on, it's a $100.00 hot deal in this neck of the woods. There was a deal on a OBD2 scanner here a while back. If I hadn't cleared my check engine light I would be all over this.

But anybody thats not a mechanic would not know aht to do with there car even if they had the number from the computer and looked it up. Some of the codes are VERY GENERAL. Like if it says lean of bank 2, most people would not know what to look for, so a scanner will not help them. At least with this the people at Autozone can look at your engine and give you a idea of what to do or at least recommened a place that will look at it without ripping you off.

 

[AllABoutTheDeals]

The damn check engine light in My 82 Z-28 used to always be on. I fixed it by opening up the dash and popping the bulb with a screw driver. Talk about cheap maintenance!

 

[mrbentley]

Autozone.com

Our Free Diagnostic Service can tell you what
caused your "Check Engine" light to come on and
what to do about it.

Does the check engine light in your vehicle come on while you drive? If so, get to AutoZone right now and we'll help you find out why.

Today's vehicle's have computers that monitor engine performance. When the onboard computer detects a problem, a light appears on your dashboard. The light either says "Check Engine", "Power Loss," or "Service Engine Soon."

When the light appears, your vehicle's On Board Diagnostic System (OBD) is sending a coded message. This "trouble code" helps you determine what's wrong with your vehicle.

At AutoZone, we can pull most trouble codes and help you understand what they mean. We'll also test individual parts for you or offer advice about what to do next.

So, get to AutoZone today and let us help you do the job right!

 

[SuperSix]

Originally posted by: AllABoutTheDeals
The damn check engine light in My 82 Z-28 used to always be on. I fixed it by opening up the dash and popping the bulb with a screw driver. Talk about cheap maintenance!

Aren't you the bright one!

 

[Evadman]

Originally posted by: mrhans

Originally posted by: Evadman
Not to crap in your deal, but on GM ( and most american cars ) you can read the codes with a paperclip.

Still works on my '99 dodge.

same trick as yellowfiero or different? details man, details!

The reader I bought does the same as the one for my s-15 that I used to have. It has 3 connectors even though the molex it connects to has a large amount more. I just plug it in, turn the ignition on, and it blinks the light. I assumed it was the same thing as the one I had for my s-15. I assumed 2 of the pins were for shorting out the connector, and the 3rd was for the LED.

I guess I was wrong.

A buddy of mine has a scan tool that will actually run an engine though its paces while it is hooked up. It checks all the sensors, varies timing, and such to make sure everything works. That is a real OBD2 scan tool. This thing that I bought was only $20 not the thousand that his cost. all those add on cartrages for different years and makes of vehics really hit the wallet.

 

[beamrider]

I read an article somewhere on how a guy made his own scanner cable that plugged into his vehicle, other end into a port on his laptop, and wrote his own software to read it all out. I'd love to be able to remember WTF I saw that at, but it looked neat as hell!

 

[SuperSix]

Originally posted by: beamrider
I read an article somewhere on how a guy made his own scanner cable that plugged into his vehicle, other end into a port on his laptop, and wrote his own software to read it all out. I'd love to be able to remember WTF I saw that at, but it looked neat as hell!

I have a similar system I use to tune my Turbo Buick. It's called Turbolink. It consists of an ALDL -> LPT cable and software. I can map/record a ton of things, including O2 sensor readings, crosscounts, injector duty cycle, shift points, etc.. It's a lifesaver when tuning a FI car.

 

[Startide Rising]

The damn check engine light in My 82 Z-28 used to always be on. I fixed it by opening up the dash and popping the bulb with a screw driver. Talk about cheap maintenance!

*heh* Always a good reason to inspect the warning lights of a used car before you buy it. Either the bulb or the wire leading to the warning light could be cut so that the warning is not available.

 

[Analog]

Originally posted by: beamrider
I read an article somewhere on how a guy made his own scanner cable that plugged into his vehicle, other end into a port on his laptop, and wrote his own software to read it all out. I'd love to be able to remember WTF I saw that at, but it looked neat as hell!

Here is a site that gives you FREE OBDII software that will allow your laptop to be plugged in and do what you say. You can actually demo the software without connecting to a car to see what it can do. It is really cool. You do have to buy (or build) the interface circuit, but they provide the schematic online. So if you're handy with a soldering iron and a fist full of parts, this isn't really that taxing to do. Especially since the software is FREE!!


LINK to FREE OBDII interface software





where to find an autozone near you:

link

 

[rehany]

Where can you buy the interface?

I can get the codes to my 95 Mustang, but don't have the tool.

thanks!

rehan

 

[knightc2]

Get in The Zone!

This is a great. Auto Zone has been doing a lot of "free" things like this lately. This should bring in new customers and makes sense for them and for the consumer. Free is good. Thanks.

I just wish I had an Auto Zone nearby.

 

[Analog]

Originally posted by: rehany
Where can you buy the interface?

I can get the codes to my 95 Mustang, but don't have the tool.

thanks!

rehan

Here

 

[Otaking]

My car's still in its warranty, so I can still go to the dealership for free (although the service was most likely paid for that service when I bought the car :confused.

But I think this is great for those annoying CELs. I already got them in my car for no apparent reason, and the service guys just said that there was a misfire, so... :disgust:

 

[Vette73]

Originally posted by: knightc2
Get in The Zone!

This is a great. Auto Zone has been doing a lot of "free" things like this lately. This should bring in new customers and makes sense for them and for the consumer. Free is good. Thanks.

I just wish I had an Auto Zone nearby.

Have you gone to their site and tried theior locator? They are the biggest auto parts store in the US. If they don't have one close by e-mail them and ask when they plan to come to your area.

 

[ween]

so I've got a 2000 jeep cherokee that I pamper like a baby. while driving to work this morning my engine light came on while just shy of 20k miles.

I headed over to autozone and the kid there figured out that I had some "blah blah blah - something else technical" wrong with the vehicle according to the computer. he goes on to say that the gas cap is often the culprit for this error. not believing him I went over to the gas station to fill up and noticed my gas cap wasn't on tight at all. damn - that kid was right.

went back to autozone w/ my tail tucked between my legs, had the kid remove the engine light warning, and I slipped him a jefferson for his trouble.

thanks for the tip on heading over to autozone. saved me a schload of money over going to the dealer.