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I was under the impression that the gauges are little more than dummy lights and they only move to make it look like they are really doing something.

If the computer were to read an unsafe oil pressure it would instantly throw the gauge to the extreme and turn on the dummy light.
 

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On the V8, the oil sensor is real, and the gauge displays the pressure. On the I6, the oil sensor is a mere on/off switch that confirms you have over 12 or 18 PSI, I forget which. EVERYTHING you see on the gauge is a fiction created by the PCM to reassure the driver that they have a true analog sensor, which they don't.

Other gauges are trustworthy - this one is a lie.

Oh, except the ECT is a lie, but at least it has true analog data feeding an algorithm that filters and compresses the data so when the temp gauge reads a reassuring and never-moving 210 degrees, the ECT can really be 185-220 degrees. I've looked at the data stream with EFILive and a Scangauge, and the evil GM design intern team did it to us with the temp gauge as well, but it's a smaller lie than the oil pressure.

Please provide a reference for the claim that the PCM can read anything like a high pressure and throw the gauge to the max. I don't see support for that in any manual I have read.
 

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Huh? Where did you get that from? Not only do I not see that in Roadie's statement, but we have NEVER seen that happen here.

On the V8, the oil pressure sensor is a true analog (continuous) sensor that doesn't lie. On the I6, I only see it as a on/off switch (can't find any evidence it's a 3-way in 2004). Other years may be different.

So the normal idle pressure display is 40 PSI, and when you rev it up the PCM adds a little bit to the display because it helps "fool" people into thinking they have a real gauge. People's mental model of an oil gauge is that it moves a bit with RPM, so the PCM programming was fiddled with to match that mental model and enhance the charade to keep Ma and Pa Kettle happy with their technologically advanced vehicle that they understand only 5% of. :weird:

For the Kettles, their trailvoy IS the Matrix. Only we on trailvoy know the truth. :thumbsup:
Maybe you could highlight the part you are referring to. I guess I'm blind.
 

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On the I6, I only see it as a on/off switch

So the normal idle pressure display is 40 PSI, and when you rev it up the PCM adds a little bit to the display because it helps "fool" people into thinking they have a real gauge.

In the on position, it does as he says, in the off, it throws it to 0.
Maybe to generically say "the computer" was a bad choice of words on my part, but some form of a processor, albeit a simple one maybe, is involved.

An example of it happening:
http://forums.trailvoy.com/showpost.php?p=680888&postcount=10

Just to review, the CHECK GAUGES light will light and very quickly go out. The gauges look fine. A few days later, the light comes on again. It took 2 or 3 times before I caught the oil gauge on 0. As the light went out, the gauge climbs back to normal.
 

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I just reread roadie's post, I didn't specifically mean high pressure, there are two extremes to a gauge you know. :)
True, but your phrase ". . . instantly throw the gauge to the extreme . . . " is what confused us (maybe I should say me).
In reality the gauge on the I6 can only go to 0 "extreme" not the 80. If your gauge goes to 80 or above (again for the I6 engine only) you have a bad gauge.

I guess your wording could have been better - but "all's well that ends well" :D
 
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