Intermittent Code 43.

I have gone through all the steps in the GM manuals and find nothing wrong.

Is it true that if the 5 volt reference wire runs parallel to a plug wire for more than 4" that the electromagnetic field can interfere?

Any help would be greatly appreciated.

Thanks,
Jeff

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I'm also getting that code and 36 this happend after i bumped my timing up to 8 degrees and ran out of race gas.
As soon as i put 92 back in the light came on. with these two codes? What is your timing set at? I have a 3rd gen though.

Give us a clue here.... what year car? In an LT1, DTC 43 is the knock sensor. If that's what FRDNemesis has, this should be in "LT1 Tech". If its a 3rd Gen like the 2nd post, DTC 43 is for the electronic spark control. Then it should be posted in "3rd Gen.....". And DTC 36 is the Opti high res pulse problem in the LT1, which of course doesn't exist in the 3rd Gens, and is the MAF burn off in SOME 3rd Gens.

Anyone see the point of including at least some basic info about your car? Anyone see the point of posting problems in the correct forum?

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Fred
94 Formula A3+1: 381/TH400+OD/N2O

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[This message has been edited by Injuneer 94FormM6 (edited September 11, 2002).]

here here

that's why mines in the title

<font face="Verdana, Arial" size="2">Originally posted by 1989gta:
here here

that's why mines in the title</font>

My comments weren't exactly pointed at you.... http://web.camaross.com/bb/smile.gif but you'd be surprised how many people have screen names like "BigV6" and post questions about LT1's or LS1's, without bothering to use the "signature" field...... http://web.camaross.com/bb/biggrin.gif

<font face="Verdana, Arial" size="2">Originally posted by Injuneer 94FormM6:
Give us a clue here.... what year car? In an LT1, DTC 43 is the knock sensor. If that's what FRDNemesis has, this should be in "LT1 Tech". If its a 3rd Gen like the 2nd post, DTC 43 is for the electronic spark control. Then it should be posted in "3rd Gen.....". And DTC 36 is the Opti high res pulse problem in the LT1, which of course doesn't exist in the 3rd Gens, and is the MAF burn off in SOME 3rd Gens.

Anyone see the point of including at least some basic info about your car? Anyone see the point of posting problems in the correct forum?

</font>


Fred,
I posted it here because it is an advanced problem. You and I both know there is not an abundance of andvanced technology on the LT1 Tech side. So to avoid what are sometimes "silly" questions and save time; I just brought it here. I fail to see why this has obviously struck a nerve, and dignified such a response. My question was not LT1 based, it was electronics based.

I hope you are having a better day; because that was not like you to respond like that.

Jeff

You still havn't answered his question, which would allow him and others to answer YOUR question http://web.camaross.com/bb/wink.gif

Also, whats the point of a sig if it doesn't say anything about your car?

Jeff

<font face="Verdana, Arial" size="2">Originally posted by FRDnemesis:

Fred,
I posted it here because it is an advanced problem. You and I both know there is not an abundance of andvanced technology on the LT1 Tech side. So to avoid what are sometimes "silly" questions and save time; I just brought it here. I fail to see why this has obviously struck a nerve, and dignified such a response. My question was not LT1 based, it was electronics based.

I hope you are having a better day; because that was not like you to respond like that.

Jeff

</font>
Jeff:

Not sure why you want to get into a pissing match.... and not sure why you feel I am having a bad day. I'm not. I believe I misunderstood the intent of your post, and I apologize for any misunderstanding. But surely you have to understand that even the question about signal interference depends on what kind of signal it may interfere with. See below....

1. Your "topic" was about "Code 43".... not anything else, so I apparently made the mistake of assuming that was the topic of your post. Since DTC 43 is not the same for ALL vehicles ever manufactured, I though it would help to know which one you are talking about.... I honestly do not have a photographic memory of what car/year/model/tran/mods evryone on this board has.... one of the drawbacks of old age and incipient senility...... http://web.camaross.com/bb/smile.gif

2. Yes, two wires running in parallel can easilly cause interference, specially when one of them is producing a cyclic 36KV signal, and the other is dealing with small variations in frequency. If you are talking about the AC noise signal that rides on the 5V reference signal (pulled down to 2.5V by the sensor) from the knock sensor, yes... that can be a definite problem. Simlar problems can result when you run a high voltage pulse wire next to the O2 sensor signal wire.... the sensor is producing a signal that varies in millivolts, and the inductive forces acting on the wire can easilly mask that signal. Ditto with the pulses from the Opti signal.... noise from an electric water pump, or stray voltage pulses from other sources can cause the pulse count to be screwed up.

If you are talking about the resistance variations that the temperature sensing thermistors provide in the 5V signal to the IAT, CLT, etc. sensor, I wouldn't think that the induction loads from an adjacent ignition wire would cause any major problems.

As far as Code 43.... if you were talking an LT1, with DTC 43 as the knock sensor.... the answer is a definite "yes". If you were talking about the DTC 43 from earlier models.... e.g. ESC module on a 3rd Gen, I wouldn't think that induction from the HV portion of the ignition would be a problem... it's already on top of the HV parts. Sooooooo.... my point about knowing the year/model of your car was not malicious.... it was an honest attempt to get the info required to answer the question intelligently. I know you have been around long enough to understand the importance of including all the required info. But you can see the confusion is caused to 89gta, who thought he was having a similar problem.

Whether this is a matter of 4" being some sort of critical value seems unimportant. It GM says that can cause a problem, they should know. My advice would be to keep the plug wires as far away from the rest of the wires as possible.

Again, my apologies for "over reacting" if that's the way you take it. All I was doing was trying to get the info required to answer the question, and that is a very frustrating issue when people don't just use the signature field to convey it.

Fred

<font face="Verdana, Arial" size="2">Originally posted by FRDnemesis:
My question was not LT1 based, it was electronics based. </font>

Jeff, If i had seen this post a while ago i probably would have moved it not to LT1 Tech but to the Computer Diagnostics forum http://web.camaross.com/bb/wink.gif But i'll leave it alone since its trukin along.

The car is a 95Z;D

Well, I tinkered with the Knock sensor harness last night. Not only was it near a plug wire; it was also next to the O2 extension harness that I have to run for my long tubes. I moved it away from the two and the SES went away. I drove it around the for a couple of miles and the Code 43 came back again. So I jacked it back up, and the wired (from hard acceleration) moved right back to its original location again. So I went to Advance Auto parts, and purchased some conduit. I placed the conduit over the KS circuit wire and zip- tied it to a secure location. Jumped back in for a drive; and problem gone! Electrical gremlins (anomalies) can be hard to chase. But its usually a relief when its an in-expensive fix.

Thanks for the insight on "Inductive Interference" Fred. I had no clue that an O2 harness could wreak havoc.

Jeff