PCM swap questions

[The beast 1500]

I'm new to these computerized vehicles when it comes to modifying the tunes. I bought a diablosport i3 tuner for my 2017 ram 1500 and I'm waiting for my unlocked pcm to arrive from holly. I've watched videos where some people start the tuning process by making a backup copy of their factory pcm then swapping the pcm with the modified one and finishing the tune. Others I've watched just put in the modified pcm and perform the tune. So which is it? Also if you just put in the modified pcm and tune it, I'm assuming that before you tuned it that the truck would start and run like the original pcm. Is that true? Any help to clarify this would be appreciated

[mikel]

for yours, and any 2015-2017, its a straightforward swap, put our unlocked pcm in and it will start and run then you can tune it.
On 18/19+ models. you need to read the SKIM data from the original PCM prior to installing the unlocked pcm so you can transfer the data to the new pcm.


Thanks

[The beast 1500]

Ok thank you. I hear about horror stories with these swapped pcms. What if the swapped pcm has a bad tune on it? Can I just use my factory pcm for the backup tune then swap the pcm and tune the unlocked pcm?

[mikel]

the new pcm is programmed by us, never had a 'bad tune' on one

You can only read the stock tune from the unlocked pcm.

[funiwant]

Ok, just so I understand how this works. I place my order for my 2017 Ram 1500, you send me a tuner/pcm. Then I send pcm back to you. So the pcm you send will start and run as usual with out "tuning" right out of the box, correct. is there any info you need before I order or is the 2017 Ram pretty much all have the same stock tune. I imagine you need gear ratio and tire size at least. Please let me know how to do this, I am really interested in doing this. Thanks, and hopfully this is an ok place to ask this question. Thanks again.

[mikel]

all we need is the VIN and part number off the pcm as indicated on the pcm swap page.
You'll put the pcm in the truck and it will just run like it did with the original pcm, then you can tune it, and return the core.