1999-2002 PCM into 1997-1998 Swap

[ArchetypeZ28]

We here at EFI Alchemy wanted to put together some pictures to try and give '97-'98 LS1-powered vehicle owners a better idea of what is involved in an '02 PCM swap and what advantages there are to doing this conversion.

The first thing you should ask yourself is, "Do I need to do this?" My answer when people ask me this varies according to the goals of the customer. If the vehicle owner only has plans for a simple bolt-on N/A set of modifications, then generally speaking the '97-'98 PCM will prove adequate. Once you start thinking of large cams, head swaps or any kind of forced induction or nitrous, then I highly recommend you swap in the newer PCM as a building block to build a foundation for all of your future modifications.

What you gain from doing this conversion is similar to upgrading your home computer from Dos to Windows XP. Overall, you gain greater resolution for fueling and spark, which allows much greater control of what is happening inside your engine and greatly improves drive ability. True real time tuning via a Moates Roadrunner PCM also becomes available to the '97-'98 owner upon completion of this swap. Having the ability to make any adjustment on the fly in real time opens up a lot more possibilities for tuning and any custom systems you may want to add to your car. Lastly, it also brings all of EFI Live’s free custom operating systems to the table, with features such as the on-the-fly ability to pull timing and add fuel for nitrous or expanded map tables for forced induction.

The basic idea of performing this swap involves removing all 300-320 wires from the PCM connectors, and remapping them into the correct positions for the '02 PCM. Unless the harness is damaged, this does not require any wires to be cut, simply pulled, and replaced into new positions on the PCM connectors. The pictures shown here are from a '97 Corvette that we completed this conversion on.

First step is to remove your old PCM and pull back the wiring loom to expose the PCM connectors and PCM harness wires.


Once you have the old PCM removed and the wires are accessible, it is time to start removing the wires from the PCM connectors. This part requires A LOT of patience. You need to be sure to only remove and label one wire at a time. Once you are done and have them all pulled and labeled, it should look something like this:


Now it's time to start re-inserting the wires back into the PCM connectors in their new locations. Go slow and be patient, it will save you a huge headache later on!


Once you have all of the wires replaced into new positions, you can take some time, wrap up the harness and make it look like it came from the factory.


All wrapped up.


New PCM mounted in the car via new '02 Corvette PCM mounts.