The need to "program" used computers?

[dragbaron]

Why is it that when buying a used computer (or like an old Mopar Performance one) that the Vin and mileage from the vehicle you're putting it in must be flashed into it, however, when doing these EFI swaps into our cars its not an issue?

I know it wasn't the case with the OBD1 stuff that I used in my Scamp, but I want to go OBD2 now. I have a '97 Dakota harness and found a '97 Ram 5.9 manual computer on Ebay. After buying it he sends me a message stating that it will need to be "programmed" to work in my vehicle, which I know is having the Vin and mileage flashed into it.

I know it won't be an issue cause lots of guys have done the swap with OBD2 setups in our cars, I guess I'm just curious as to why this computer needs flashed to put it in a another '97 Ram, but is not an issue when putting it in my Scamp with a stripped down Dakota harness.

 

[1963dartgt]

If I'm not mistaken it's just for proper smog information so when they hook it up to the computer they know that vehicle is on the dyno and not some other one.

 

[Oaktree]

If I'm not mistaken it's just for proper smog information so when they hook it up to the computer they know that vehicle is on the dyno and not some other one.

Dunno how it works in your state, but here in N.H. OBD is part of the annual state safety inspection on 1996 and newer vehicles. The computer at the garage will read the VIN from the vehicle, if it doesn't match what's on the VIN plate it's an automatic fail. Inspection stations' computers are tied into the DMV so it'll go in their database that you failed and why.
Not an issue on 1995 and older vehicles since that test isn't part of the inspection here.

 

[68gtxman]

That explains what NJ recently exempted all 1995 and older vehicles from state inspection (which is now only emissions).

 

[dragbaron]

Funny, the computer I bought is coming from NH. Now we know why he made sure to tell me about "reprogramming" the computer.
Should've known the Vin/mileage flash deal was for crap like that! That just means I wasted money years ago when I bought a MP computer for my first Dakota R/T and took it to the dealer for the flash. There's no emissions or state inspections in my area of NM, and it never would've went to a dealership for repairs, so I probably didn't need the flash!

 

[magnummopar]

not necessarily, in a vehicle with a data buss, you need vin for it to communicate with body computer in some instances or you wont get buss info, also if you have SKiM or alarm, you need vin or it wont start at all.

 

[dragbaron]

not necessarily, in a vehicle with a data buss, you need vin for it to communicate with body computer in some instances or you wont get buss info, also if you have SKiM or alarm, you need vin or it wont start at all.

Well, hopefully I have no issues with the '97 harness I have as far as alarm or BCM goes, cause I don't know if it had any of that. I know the SKIM stuff was maybe started in the early 2000s. I had to deal with flashes because of the SKIM key stuff on a couple SRT4 Neons when we swapped computers, they would only start for a few seconds then die until the flash was done.