1994 corvette will not start, part 2
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From: Orland Park ILL.
1994 corvette will not start, part 2
Thanks everbody for the help so far, here is where I am . Code H 16 no spark, new coil, icm tested good all fuses tested good. I have power going to the opti terminal C. I put a volt meter on terminal A to check for low resolution signal and I get 5 volts when meter is on DC and I get 10 volts when meter is on AC. This reading is there anytime the key is on. Also the reading is the same when cranking. I was told that this reading should be there only when the engine is cranking? Is this bad or am I on the wrong terminal?
Thanks Mike
Thanks Mike
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From: Orlando FL
Thanks everbody for the help so far, here is where I am . Code H 16 no spark, new coil, icm tested good all fuses tested good. I have power going to the opti terminal C. I put a volt meter on terminal A to check for low resolution signal and I get 5 volts when meter is on DC and I get 10 volts when meter is on AC. This reading is there anytime the key is on. Also the reading is the same when cranking. I was told that this reading should be there only when the engine is cranking? Is this bad or am I on the wrong terminal?
Thanks Mike
Thanks Mike
I’m out of town but I know that is correct.
Two other terminals (A & D) have 12 volts DC on them and the other (C) is ground. (from memory).
Last edited by pcolt94; Jun 15, 2011 at 08:55 PM.
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From: Orland Park ILL.
My icm plug reads this A 11.52volts, B no volts while cranking, C is a good ground and D 11.52 volts. I seen that a H 16 code could only be caused by an open, shorted, or grounded low resolution wire comming from the opti or a bad optial sensor diode or a bad pcm is there any way to pin point it down? Is this information correct I seen it on u tube for gm training?
Thanks Mike
Thanks Mike
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With the code 16 and especially not having A/C drive voltgage at pin B.
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I put a noid light on and got nothing, I was just hoping in was something else than the opti. What the chance it is the pcm? I just didnt want to do the opti if it wasnt the problem. Thanks everone.
Mike
Mike
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The opti provides the initial timing and clocking pulses (drive) to operate the PCM. No opti operation, no injector drive or ICM drive. To test these individual parts require complex set ups. Of course the PCM could give a similar symptom. So for the average guy fixing his (or her) car, replacement or best educated guess sometimes is the only way to further the diagnosis.
The PCMs are good units unlike the ECMs. Optis are a much higher failure item than a PCM and the odds are in you favor.
Of course is easier to change the PCM just to try it if you had one on your back pocket.
The PCMs are good units unlike the ECMs. Optis are a much higher failure item than a PCM and the odds are in you favor.
Of course is easier to change the PCM just to try it if you had one on your back pocket.
