Code 12?
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Le Mans Master
Joined: Aug 2006
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From: Just the Tip... Just to see how it feels...
Code 12?
My check engine light came on so I started to do a diagnostic check yesterday. I did this years ago with good results, but yesterday really confused me.
I opened up th ALDL and Jumped ports A & B and then turned the key to the "on" position. Just as it should code 12 flashed (*flash* pause *flash**flash*). After code 12 flashed 3 times, to my surprise, it kept going.
All that was happening was flash, pause, and then two flashes. over and over.
Am i missing something???
thanks in advance guys.
I opened up th ALDL and Jumped ports A & B and then turned the key to the "on" position. Just as it should code 12 flashed (*flash* pause *flash**flash*). After code 12 flashed 3 times, to my surprise, it kept going.
All that was happening was flash, pause, and then two flashes. over and over.
Am i missing something???
thanks in advance guys.
Race Director
Joined: Feb 2004
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Originally Posted by RRT vette
It is telling you no code was stored, as you know. I believe there is something on this in the FSM.
The code 12 flashes 3x before a code is shown and 3x after. A non stop 12 means no codes at all.
Thread Starter
Le Mans Master
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From: Just the Tip... Just to see how it feels...
That seems to be the case in my chiltons, Code 12 means system is normal. Hmmm. I did disconnect the battery to clear the codes, BUT it came up the same again. I know my car is having some serious problems right now, and I'm trying to pin them down.
I know my car is having some serious problems right now, and I'm trying to pin them down.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
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From: Louisiana
Did the SES light come on and you disconnected the battery and then try and pull codes? The SES light has to be on, before you can get the code. In the FSM, it usually states to clear the codes and idle the engine for something like one minute or until the SES light comes on and then pull the code...then follow the troubleshooting steps.
Code 12 is normal and just tells you the ECM is in diagnostic mode. The main fan and various sensors and relays will energize while the ALDL is grounded.
Code 12 is normal and just tells you the ECM is in diagnostic mode. The main fan and various sensors and relays will energize while the ALDL is grounded.
Thread Starter
Le Mans Master
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From: Just the Tip... Just to see how it feels...
I cant even get the vette to turn over, Its been sitting for the better part of a year with numerous problems. I finally got fed up with not driving it and started working on it recently. The check engine light IS on when the car is in the "on" postion.
I should be having it trailored to the mechanic soon, but i figured i should get a good idea of whats wrong first.
I should be having it trailored to the mechanic soon, but i figured i should get a good idea of whats wrong first.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
With the key in the "on" postion, the check engine light will be on among others...normal. If the check engine light is on while the engine is running then there is a code. What type of problem are you having? You say it want turn over. Is the battery good? is the starter good? If you have any skill or initiation, you can start working on things using the forum to help.
Race Director
Joined: Feb 2004
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The check engine light normally comes on while the key is in the run position, prior to starting. After the engine starts, it usually goes out. You may have a vats problem if you turn the key and nothing happens.
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Thread Starter
Le Mans Master
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From: Just the Tip... Just to see how it feels...
Oh jeez, I totally forgot that. 
When I was driving it, the car would idle very rough and continue rough in low RPM's. In high RPMs it would smooth out. Like I said its been over a year since i drove it so i may not remember perfectly. Also one of the injectors was leaking gas. Not sure if they are numbered for reference, but its the rear most injector on the drivers side. My friend who does a lot of mechanical work swore that he remembered that the car was knocking the last time i drove it.
When I was driving it, the car would idle very rough and continue rough in low RPM's. In high RPMs it would smooth out. Like I said its been over a year since i drove it so i may not remember perfectly. Also one of the injectors was leaking gas. Not sure if they are numbered for reference, but its the rear most injector on the drivers side. My friend who does a lot of mechanical work swore that he remembered that the car was knocking the last time i drove it.
Le Mans Master
Joined: Feb 2006
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From: Louisiana
You can spend a little money on tools upfront and do the work yourself. A fuel pressure guage, volt/ohm meter, test light, vaccum guage (optional), a good set of tools (Sears tool set), and a FSM for your year car. With these tools you can almost do anything on these cars. You can even rent for free some of the odd tools needed once from Autozone.
The rough idle could be lots of things including injectors. A fuel pressure guage and ohm meter will help with diagnosing a faulty injector.
The rough idle could be lots of things including injectors. A fuel pressure guage and ohm meter will help with diagnosing a faulty injector.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
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From: Louisiana
It is o.k. to run it with a leaky injector. It will probably idle/run rough and may run rich. Depends on how many are leaking. It's a pretty easy fix with the right tools. You can pull some plugs (esp the one suspected) after you get the fuel pump to prime the fuel lines. Pull them to see if any are gas soaked.
Thread Starter
Le Mans Master
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From: Just the Tip... Just to see how it feels...
I figure i would be changing my injectors soon. According to my chilton i have to take off the throttle body, plenum, and runners before i can get to the fuel rail to take the injectors off. This project does seem a bit scary, but is suppose that is the only way to pull the injectors?
Le Mans Master
Joined: Feb 2006
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From: Louisiana
Originally Posted by zo1boy
I figure i would be changing my injectors soon. According to my chilton i have to take off the throttle body, plenum, and runners before i can get to the fuel rail to take the injectors off. This project does seem a bit scary, but is suppose that is the only way to pull the injectors?
Thread Starter
Le Mans Master
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From: Just the Tip... Just to see how it feels...
Originally Posted by RRT vette
PM Sam Lam about this I believe he has a step by step guide he can send you. This forum is a tool in itself.
What is Sam Lam's user name?
