Prominator Install on 1227165 ECM
(Photos and write-up by Craig Moates 01/17/04)

The "Prominator" is a pretty slick little deal from Bill Hitchcock and Ken Kelly. It replaces the chip in your stock GM ECM, and allows you to upload new binary content by using a PC and parallel port. It's not a real-time emulator, but it makes your 'chipped' car more like the 94/95 LT1s such that you can reflash the content without having to gain real access to the ECM, just a cable going to it.

The software interface is Windows-based and dead-simple, so I won't go into that. This write-up is targeted toward describing the physical installation.

Step 1: Take the ECM apart. You'll have to do this to get the Prominator under the top cover.

Step 2: Connect the Prominator to a socketed chip adapter like the Moates.Net adapter shown below.

Notes: I tried mounting the Prominator directly into the adapter without a socket in between, but I'd cut the Prominator legs a little too short to maintain clearance with the rest of the adapter, namely the right angle header that goes to the stock Memcal. If I had kept them longer, I could have replaced the adapter socket with the Prominator legs for a full soldered-in deal. While Bill doesn't recommend sticking the Prominator into a socket because of the possibility of intermittent connection, I think it will be just fine based on my experiences, especially considering the beefy leg thickness of the Prominator header. However, if you have a machine-tooled socket, then the legs will be just a bit too thick and you'll have to take the socket out or replace it with another one.

Here I show the 'misfit' because of the legs being too short to bring the Prominator up high enough to clear the angle header:

And here it is with a socket in between which raises it up to a more workable height:

Step 3: Put the Prominator/adapter assembly in the ECM. This requires that you bend some of the sheet metal (obvious in pictures shown what I mean). Also, you'll have to cut the top cover of the ECM sheet metal, not just the lid, to allow the parallel cable socket to come up. It's too tall for the whole thing to fit in the ECM. But, everything except the socket header fits just fine. You'll also need to trim the top of the little latch arm as shown so it'll clear the bottom of the Prominator. You'll notice that the bent piece of internal sheet metal now doesn't line up with the screw holes, but that should be OK. All in all, not too bad. Just a quick snip, bend, and cutout, and you're done.

Step 4: Hook up the cable, load up the BIN in the provided Windows software, and upload it to the Prominator. Whatever you do, DON'T put the Prominator into the ECM backwards! Also note that the Prominator is powered from the car's ECM, so the car must be keyed on to provide the supply power during upload and subsequent verification. The car will probably do some funny stuff while the upload is going, so don't have it running! Once the upload and verify is complete though, it should run as normal even with cable attached.

Hope this helps! I had a 32k version of the Prominator, so on first attempt to upload a 16k BIN, the ECM didn't know what to do. After I figured that out and uploaded a stacked BIN, it ran without a hitch. Ran it for a good long while without any blips.

Have fun!
-Craig