kenp

iTrader: (9)

If you put together a PCM from one car and a dash cluster from another, what will happen to the mileage on the odometer?

In other words, if I put a pcm from a car with 50K miles in a car with 25K miles, does the pcm log the mileage or is that only recorded in the odometer?

Hope the question makes sense.

A_W_O_L

iTrader: (2)

Im not sure if the PCM logs milage or not...I dont think that it does, and I base that off of the fact that Ive never heard anyone mention it...if it does then I dont think that anyone has "Cracked" that part of the coding yet.

To answer the other part of your question though....using your example of a PCM with 50K in a car with a dash cluster with 25K on the clock....the dash cluster will display 25K...and count up from there.

Im sure that there is a way to "even" the two up but I doubt that any of the tuners would attempt something like that due to legal "issues"

Hope this helps

FWIW...I went through this with my 97 Camaro swap 2 years ago....it was a V6...

12secSS

iTrader: (30)

That is correct, but the PCM will also keep going up in mileage. I have heard that it does store mileage, but it may not referrence the odometer reading. The PCM give the odometer the mileage to add. I don't know of any tuning program that can legally access it, beside (and probably not) Tech-II.

horist

I haven't heard positive one way or the other about the PCM storing mileage... I do know that the Odometer is fed off the speedometer... so if hte PCM stores mileage also, it doesn't talk to the odometer on any updates...

I believe if you get a new cluster from GM, they have the ability to reprogram the Odometer to the proper mileage, however if you're using a different odometer, I think it'll keep whatever mileage was previously in that gauge cluster and count up from there....

Rob

iTrader: (6)

With an autotap on my 2000 Malibu, the mileage was there. It was actually off a couple of miles from the odometer also.

kenp

iTrader: (9)

Thanks guys. It sounds like no conflict exists if a change of either the dash cluster or pcm is necessary, so changing the pcm doesn't change the odometer.

horist

changing the PCM definetly 100% doesn't effect the mileage reported on the odometer.... I've had quite a few different PCMs in my car and never had a problem w/the reported mileage.

(though the PCM can affect the odometer if the tire size/gearing is wrong, in which case the Speedometer is wrong, which causes the odometer to count wrong)