odometer mileage display

[awesomeame]

did some reading on this already, using the search feature [img]smile.gif[/img]

seems there's a chip in the gage cluster which keeps track of the mileage & displays it on the odometer. the pcm also keeps track of mileage, but is only readable with a scanning tool.

now if i change the cluster with another v6 car, the displayed mileage on the odometer will reflect that of the other v6 car.

my question: is this correct?

--matt

[firebird1]

i would think the pcm overrides the chip..

[awesomeame]

the pcm definitly does not override the chip....my pcm shows approx 300miles more than my odometer display does. i thought that was very wierd when i first saw that :-|

i think i just answered my original question

--matt

[awesomeame]

maybe a better question is, can i change the cluster & not the pcm? like will the chip inside the cluster work with any VIN, or will it not work at all?

--matt

[Lord_Verminaard]

I've asked this question as well, so far no answers. I'd also like to know what this "mystery capacitor" is that can be swapped from a V8 to V6 cluster and allow the tach to work properly. I'd like to know, even though it will be a week or two before I am ready to swap clusters.

Brendan
2000 Camaro L36 M49

[Camaro_SLP]

The pcm only reads miles for OBD2..which started in 96? Earlier models, only the odometer keeps track,,and the pcm has nothing to do with it.

You can change the cluster without changing the pcm. Your VIN does not matter at all.

[Camaro 22]

I have a 97 camaro. I'm doing a v8 swap in Jan. I bought a 97 z28 cluster with over 100k miles on it. I just took my lcd/chip out of my cluster and switched it with the z28 cluster, and now my miles are back to the original miles using the z28 cluster. Simple as that.

[Lord_Verminaard]

Wish it was that easy on mine. I can take apart the LCD display unit, but there is no chip on it for odometer information. Instead, there is a ribbon cable that goes from the LCD to a raised circuit board with memory chips on it. It doesnt look like that can be removed easily. I'm guessing the dealerships use a scantool to re-flash the memory chips in the cluster to what the PCM has in memory. I'll try to contact a local chevy dealer and find out.

Brendan
2000 Camaro L36 M49

[slow]

you sure it is the PCM and not the BCM that keeps milage?

Ryan.

[Camaro 22]

You just unplug the harness that goes to the lcd/chip. just pull it straight out, thats what I did, and reverse your steps to put them back in. It's really simple. The hardest part is getting inside the cluster.

[slow]

im not worried about how to do that, that is simple.

I am trying to find out if the V6 cars are different in milage storage than the V8 cars.

Ryan [img]smile.gif[/img]

[Lord_Verminaard]

<blockquote>quote:</font><hr> You just unplug the harness that goes to the lcd/chip. just pull it straight out, thats what I did, and reverse your steps to put them back in. It's really simple. The hardest part is getting inside the cluster. <hr></blockquote>

So the odometer milage is in the LCD display, huh? Ok, I'll try. I pulled it out once to see but there didnt look like there were any chips or anything on it. It will probably be happening sometime next week, I'll report my results. By the way, anyone have information on the resistor swap to correct tach operation? (there are a lot of resistors on these things!!) I'd like to put an end to that rumor as well. Thankee!

Brendan
2000 Camaro L36 M49

[Lord_Verminaard]

Update: swapped clusters yesterday. My gauge face wired up fine and they look great. Some issues:

Despite swapping the LCD unit from my old cluster to my new one, the odometer is incorrect, reading miles from the Z28 cluster. I will be contacting a dealership to see if they can fix it without much hassle.

Tach is off (as expected) reading about 400 rpm's too high. Will be eventually getting a DD tach converter to fix that. Is the DD unit wired into the tach signal from the coil packs or from the pcm to the cluster?

On a side note- the annoying tach lag that my V6 cluster had has been reduced about 50%, still there but not as bad.

Oil pressure is also reading incorrect. The V8 cluster has 40psi in the twelve o'clock position, 80psi max, where the V6 cluster shows 60psi in the twelve o'clock position. The needle is pointing in the same place as it usually did with the V6 cluster in there, which means that the PCM doesnt feed the cluster with actual psi readings but instead just tells it where the needle should be pointing. Speed, fuel, and temp are all acting normal. I will be adding water temp and oil psi gauges from autometer eventually.

So that's it. One thing that made the install easier is to unbolt and lower the steering column, only takes two minutes and makes removal and installation of the cluster and bezel MUCH easier. From start to finish it took me about two hours, including wiring. The end result is a pretty wicked looking dash cluster.

Thanks for the bandwidth-

Brendan
2000 Camaro L36 M49

[Lord_Verminaard]

A further update: Contacted an "inside source" at a local chevy dealer about how to re-program the odometer. Bad news: the cluster needs to be shipped out to a GM service center to be re-programmed, costs about $120 and takes five days. He said that some clusters can be programmed with the TECH-II and some cant. I just happen to have one that cant. All the while, I've been driving around with incorrect milage for a week and even if I put my stock cluster back on, it will be off. Although, I would rather it be off by 300 miles than 13,000 miles.
So now, I am putting my stocker back in. Anyone want to buy a Z28 cluster with reverse-glow euro gauges, carbon fiber bezel? Has 40,900 or so miles on the odometer. [img]smile.gif[/img]

Brendan
2000 Camaro L36 M49

[A 2 Z-28]

I am very interested... What year is it off of and how much do you want? Thanks!