PCM Swap Question

[HotRodV6]

Ok, on my 2003 Silverado i have the 05+ OEM fans installed, and i also have a stock 05 5.3L cal file that i was trying to reflash to my stock PCM, but it said that the cal file was from a 12589463 and my stock PCM is a 12582605, i said go ahead but after 3 times it said it couldnt do it.

So my question is, i found a guy that has a 2005 PCM that is 12589463 ser #, from a 6.0L, he wants 50 bucks for it. Will this go directly into my truck, and then i can flash it with the stock 2005 5.3L cal file?

My goal is to get the fans working like they were there from the factory, is this is the cheapest way i can go, till i get the cash to get a tune from NP.

I dont think they changed the wiring harness, but this is why im asking.

Thanks

[farmtruc]

The reason why you can't flash the 03 is because the software won't allow it, the OS's have to be compatible.

You do have the correct SN PCM 463, that is an '05. I'm not sure if you can flash an 03 cal on an '05, I just haven't had to do it yet.

Go ahead and try it, just save your current file first, then you can go back to it if it doesn work. BUT, you may get the same error because you're still trying to flash over an 05 cal.

[HotRodV6]

The reason why you can't flash the 03 is because the software won't allow it, the OS's have to be compatible.

You do have the correct SN PCM 463, that is an '05. I'm not sure if you can flash an 03 cal on an '05, I just haven't had to do it yet.

Go ahead and try it, just save your current file first, then you can go back to it if it doesn work. BUT, you may get the same error because you're still trying to flash over an 05 cal.

yeah i figured the OS's were different. But i dont want to use my stock 03 cal at all. The 05 PCm is from a 6.0L truck, and i have a cal file for an 05 5.3 that i want to flash into it, same year and same PCM number, my question was more to make sure they didnt change the wiring harness from 03 to 05, id hate to plug in the PCm and fry my truck to the ground.

[Chevy366]

People flash different OSs on PCMs all the time , the 03 may be 512 and the 05 is 1mg of space why you can't do it , or HPTuners just can't .
Some may have small differences that may effect the way the engine will run and you have to do a segment swap .
The connections are the same .

[HotRodV6]

People flash different OSs on PCMs all the time , the 03 may be 512 and the 05 is 1mg of space why you can't do it , or HPTuners just can't .
Some may have small differences that may effect the way the engine will run and you have to do a segment swap .
The connections are the same .

well im using Tunercat OBD2 tuner and winflash to flash the PCM, im sure the 05 program was to big for the 03 PCM, like you said. But as long as the connections are the same, im good.

Thanks for the info.