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Idiot Light

stockk5

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Hey, just wondering what usually causes the check engine light to go on? all my fluids are up to normal levels, my idiot light for the temp hasnt gone on.. and my engine seems to be running perfect. The light comes on randomly i think after driving the truck for a lil bit.. say like 10mins on the highway or heavy gas (mud) To me that ment hot.. but the temp lights not going on so who knows. Should i not be concerned at all? just kinda annoying at night w/ this orange light in my face. Just recently started to and i didnt change anything on it since i put the motor in a few months ago. thanks! Mike
 
A little more info would be nice- year, model, drivetrain........

BTW, you should fill out your profile so we don't have to ask, brother.
 
The truck in my siggy does it with the oil light and scare the crap out of me. I put in a gauge and now I don't worry. Its Gremlins!
 
CanmoreK5 said:
A little more info would be nice- year, model, drivetrain........

BTW, you should fill out your profile so we don't have to ask, brother.

He said Brother I think I started something ;)
 
opps sorry guys its an 87k5 blazer w/ a 350 tbi/700r/208, lift, some tires u know that stuff.
 
stockk5 said:
opps sorry guys its an 87k5 blazer w/ a 350 tbi/700r/208, lift, some tires u know that stuff.

TBI means computer, so the only way you're gonna find out is do the diagnostic thing. Some places like Vatozone will hook a reader up for ya (free or cheap), or you can do the paperclip thing and read the light yourself.

Search for "ALDL" and you'll find out WAY more than you wanted to know.

-- A
 
Save you some time.

Does your 1982- 1995 Chevy/GMC Truck have a check engine light on? Is the dealership telling you that they will charge you $80 to tell you what your truck is silently telling you? Well fear no more! OBD-1 is (on-board-diagnostic) yes, onboard. I will explain to you how to figure out what your truck is telling you. It isn’t hard and only will require a piece of paper, a paper clip and a pen. Yes, it is that simple. Ready? Let’s begin.

On every vehicle you have a diagnostic port underneath the steering wheel column. If you get down you will see little pins sticking out of them, it is almost as though something is meant to slide on. Well there is such a tool but we won’t bother with that. Now make sure your truck is off with key out of ignition. Take the paper clip and open it up. Make the paper clip into the shape of a U with a quarter inch separating the ends apart. While looking at the Diagnostic port, you will see some openings all the way across the top and bottom. The TOP row all the way to the RIGHT. So the TOP RIGHT TWO OPENINGS (sorry for the large print, I just want to make sure some people insert the paper clip into the correct holes).

Insert one side of the paper clip into the hole to the top and to the farthest right. The other paper clip should be inserted to the hole directly to the left. So it would be the second to the right. Now, Sit in your trucks seat and get your pen and paper. Be ready to write some numbers.
Only do this next step when you are ready. You might want to get a friend to read the code while you write them down. The code will come out like Morse code in a way.

After turning the key the check engine light will Blink "12" When I tell you a number, I mean it will blink as so. For 12 (which is the beginning code, don’t worry, it means nothing, it is just letting you know that the computer is working and the trouble codes are being brought up) it will blink as so

" 1 " " 1-1" <---12. see it? Now if you were to have a trouble code of....
" 1-1-1-"____"1-1-1-1-1"____________ that would be a trouble code of 35. Get it? Then it will pause for a bit longer and throw out "1-1-1-"____"1-1-1-1-1"_____________. Easy eh!

Here is a list to a few web pages that lists GM Trouble Codes.
http://www.troublecodes.net/GM/
http://www.tradervar.com/GM_Codes.htm

Once you get the codes, Unhook the battery for about a minute, and then hook it up to get the computer back online. If any new codes appear, the computer will remember it.
 
That's some very useful information metrodps! I got an engine light that keeps coming on and I found it was a stuck egr valve. It came on again tonight and once I hit the freeway, the light went out. I'm thinking of taking out the egr valve and use some JB Quik and seal the damn thing shut....my Blazer has nothing for emissions or smog control anyway, it passed emissions last month. The only thing I'm required to have is the charcoal canister, but the inspection guys didn't even bother to look.
Anyways off point here.. I'll be sure to look up that info next time the darn light comes back on.
 
hey guys.. to bring this back up i cant get my truck to give me any codes at all.. i keep doing what that link up above says and nothing at all. Does this need to be done w/ the check engine light on? cuz mines not on all the time. I've tried it w/ the check engine light. doesnt seem to make a difference, still no codes, not to sure whats up. My truck keeps dieing out on me randomly while taking off from a stop, pretty annoying. Any other thoughts? my paper clip just not the right size?
 
Hopefully you're not trying the paperclip with the engine running as it could blow the ECM. The key needs to be in the ON position and the engine off then the light will blink any codes that are stored starting with a code 12 telling you the system is working properly then any other codes will follow ended with the code 12.
 
yeah no. i follow the directions.. engine off keys out. .. i put the paper clip in A&B and then turn the key to ON position.. so electric is on... and nothing.. i think i might just have someone plug it in for me, see if i can get my connections working w/ who i know.
 

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