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Old 03-19-2012, 04:56 PM   #21
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Wow, what are the chances of that happening?

Find the 2 pins(I'm basing this off of my Bonneville) 1. is constant battery power and 2. ignition voltage.

Check those 2 pins to see if you have true 12v. I'm wondering if low voltage goint to the PCM is causing your TPS voltage to be low.
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Old 03-19-2012, 05:29 PM   #22
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What color r they?
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Old 03-19-2012, 05:36 PM   #23
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Is it posible to transfer this thread to like performance threatds to see if some one had this problem too?
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Old 03-19-2012, 05:40 PM   #24
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I have no idea what colors they are. I could reference my 2000 Blazer, but I don't know if you have the same PCM or not.

Moving this to another section isn't going to help either. That section is more for modding.
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Old 03-19-2012, 06:12 PM   #25
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The blazer jimmy and the truck if it'* 4.3L are the same ill ck if I can find them
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Old 03-19-2012, 06:22 PM   #26
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I don't know if u can but is it possible that u can find out the voltage of ur tps sensor out of ir blazer and maybe find out if it have 5 volts it'* the gray cable the sensor have 3 cables a black a green and a gray please and let me know
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Old 03-19-2012, 06:32 PM   #27
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Sure can, I'm already out in the garage... gimme a few and I'll check.
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Old 03-19-2012, 06:41 PM   #28
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With power on, engine off, I'm getting 5v on the gray wire, and .5 volts on the return wire. Either you have another bad pcm, or low voltage between the PCM and the battery. If you have a scantool that can tell you the PCM voltage, that will get rid of the low voltage test.

Other than that, I cannot think of anything else. But, don't run off yet. I need to renew my AllData subscription for the Blazer. I'll research more once I do that.
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Old 03-19-2012, 06:51 PM   #29
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I'm moving this to a different section for more visibility.
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Old 03-19-2012, 06:59 PM   #30
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I found the pinouts for my PCM. Check your voltage at these pins...

C3-CLR-PIN 21= Battery voltage

C4-BLK-PIN 17 and 18=Ignition voltage.

All three of those pins should show battery voltage. For the last 2 pins, you will have to have the key turned on, engine on or off, don't matter.
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