That stupid nonsense was started by GM as a way to extract more money from their unsuspecting owners after the sale, beginning with 2002 models. The ONLY reason for requiring the VIN to be programmed in is to prevent you from being able to buy a low-cost replacement computer from a salvage yard. All of their other computers such as air bag, anti-lock brakes, auto-load-leveling, body, etc, (up to 47 total on one vehicle), that have nothing to do with emissions, still require programming at the dealership when they're replaced. That does absolutely nothing to benefit the owner but it does plenty to make money for the dealership and GM. It's one of the many reasons GM is one of the least customer-friendly companies in the world. They even build the body computer into the high-failure radio now so you can't install an inexpensive aftermarket replacement. They have it all figured out.
Unfortunately, whatever BS General Motors figures out, other manufacturers tend to copy a few years later. Chrysler has been the leader in useful and beneficial innovations as far back as before 1960 when they introduced the very efficient alternator, (a term they copyrighted), anti-lock brakes, (1969), electronic voltage regulator, (1970), electronic ignition, (1972), lockup torque converter, (1977), domestic front-wheel-drive, (1978), high-mileage car that easily got 54 miles per gallon with a simple carburetor - Horizon Miser, (1980), air bag, (1987).
Ford's innovations include saving 20 cents per car on the assembly line by leaving off four grease fittings on the ball joints, (1977), Escort and Tempo outer tie rod ends that lasted about 20,000 miles, (1984). They could check good one day and separate a week later leading to a serious crash. Escort and Tempo front wheel alignment that was non-adjustable and had the tires tilted WAY out on top. Tires lasted 15,000 miles if you were lucky, but they rode real smoothly compared to other brands of small cars so they sold a pile of them, rubber-bonded outer tie rod ends, (late 1980s) on their cars and light trucks; basically a design-waiting-to-fail leading to loss of steering control, involving two computers, (the instrument cluster and the front electronic module), in blowing the horn. Typical repair bill for a dead horn is $800.00! (Late 1990s).
I can't even elaborate on GM's practices without getting a headache. I've written five-page articles on all the unscrupulous things they've done to benefit the company without providing any real benefit to the owner. As with corrupt left-wing politicians, whatever GM puts in their advertising, people automatically believe it and will argue against anyone who points out the flaws in the logic. That has been changing in the last few years because GM is having a much harder time finding repeat customers. Hyundai, Toyota, and Chrysler are gaining customer loyalty although Chrysler is starting to copy more and more of GM's policies so I expect their future sales to drop too.
Okay, let me get down off my soapbox and address your question. As best as I can recall, there should not be any programming required for a used or new Engine Computer as far as emissions is concerned. There may be an issue though with the factory anti-theft system. I left the dealership in '99 and up until then I only replaced one computer in a '96 or '97 model and I don't recall having to program anything. There is a concern on the cars that I can share if you ask, but for the minivans, if yours has the factory anti-theft system and you install a new Engine Computer or a used one from a van without it, you have to "teach" the anti-theft programming to the replacement computer by turning the lock cylinder in the lift gate. After that, the keyless remote and anti-theft will work and the engine will start. On the cars, if you DO NOT have the anti-theft system, you MUST find a used Engine Computer or Body Computer from a donor car that also did not have that system. That can be impossible to figure out in a salvage yard. I can't remember for sure, and I don't want to steer you wrong, but the best I recall, if you don't have anti-theft on your van and you install a used computer from a van with anti-theft, the engine won't start. I think simply installing a different computer is all that's needed. If I'm wrong, that new computer with anti-theft programmed in will teach it to the Body Computer which will then also have to be replaced. That "upgrade" programming to anti-theft can't be undone once it takes place. Again, this is all irrelevant if your van does have anti-theft. Any computer will work, but the engine may not start until you cycle the lift gate lock.
Thursday, October 13th, 2011 AT 7:51 PM