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Codes for both knock sensors are on

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Old Nov 22, 2002 | 07:25 PM
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Default Codes for both knock sensors are on

I had my PCM programed and in the proccess had the knock sensors made a little less sensetive. I don't know if it is a coincidence or not but I just had P0332 & P0327 knock sensor 1 & 2 signal short or low come on. I called the progam guy and he explained that changing the KS attack value or whatever will not affect the signal. Anyone have any clues. The connector is pluged in behind the intake. I am short on time before leaving and need help desperately.

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<small>[ November 22, 2002, 07:26 PM: Message edited by: topfig1 ]</small>
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Old Nov 23, 2002 | 05:35 AM
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Default Re: Codes for both knock sensors are on

The tuner is right. Throwing both codes usually means that your wire is bad, or the pcm is fried. The first step is to have your pcm checked, and replace it if necessary; if your pcm is okay you need to pull the intake and check your wire and replace it (I would change the knock sensors, too, while you have everything apart), and finally do the GM TSB by sealing the rubber boots with RTV, and removing the foam squares under the intake.
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Old Nov 23, 2002 | 10:09 AM
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Default Re: Codes for both knock sensors are on

I have to believe it's the wire since I just did a complete rebuild. Could everything in the PCM work fine except for my problem and the PCM be fried?

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Old Nov 23, 2002 | 11:26 AM
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Default Re: Codes for both knock sensors are on

In my case, the pcm was the cause of the codes, and when I logged runs, I had very low maf air flow readings which weren't making sense. Since replacing the pcm, the codes disappeared, and maf air flow is reporting normal. Also, I had a burnt pin #51 that actually fell off when I touched it.

Since your pcm seems to be working okay, and you've had the intake off, it's most likely the wire. You have to be very careful routing the wire: it needs to lay along the passenger side of the valley, but to the right of where the intake seats. Don't forget the GM TSB. Good luck!
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Old Nov 23, 2002 | 03:04 PM
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Default Re: Codes for both knock sensors are on

Well, connection is good, wire checks good and Knock sensors check good so the PCM will go back and I will have the Knock sensor sensitivity put back to stock.

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Old Nov 23, 2002 | 04:35 PM
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Default Re: Codes for both knock sensors are on

Editing the knock tables shouldn't cause those codes.
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Old Nov 23, 2002 | 04:44 PM
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Default Re: Codes for both knock sensors are on

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Predator:
<strong>Editing the knock tables shouldn't cause those codes.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thats what the tuner and I both said but I put 500 miles on the engine after the Heads and cam swap and the only SES code was random missfires. Got tunning to include desensitizing the KS's and the code immediately popped up. All is well with the sensors and everything associated with them so IMO it has to be the tunning. Once I get the PCM back I will post and I think we will both learn something new.

topfig
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Old Nov 24, 2002 | 04:06 AM
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Default Re: Codes for both knock sensors are on

Did you take out your pcm and look at the pins?

It seems to me that if you return the knock table back to stock, and the codes disappear, then your pcm is faulty. You should be able to edit those tables, without codes, on a normally functioning pcm. If that turns out to be the case, at the very least, I would have my pcm reflashed. If the problem ocurred after that, I would replace the pcm. This is of course assuming that your ks circuit is okay, as you stated.

The guy that checked my pcm, aside from the burnt pin #51, said that part of my original flashed was erased. Something else to think about.

Yes, post your results. Good luck!
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Old Nov 24, 2002 | 11:27 AM
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Default Re: Codes for both knock sensors are on

Ihad the same problem with my car i had the intake off and it after i put it back togetehr it threw the same code po327 and i acutally hada wire pinched between teh valley cover and a rib on the bottom of the intake and was shorting the wire out
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Old Nov 25, 2002 | 12:46 AM
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Default Re: Codes for both knock sensors are on

I've seen that happen. We checked resistance and knock sensor operation and both are good. The only place it could be in is the PCM.

Fig
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