Ok, I just got myself a '01 LS1 for my '91 TPI Camaro. With the LS1 I also got the harness. I have some questions that hopefully you can answer. I will first post a pic of the LS1 harness.




1. If the harness and PCM was originally from camaro with automatic tranny can I use PCM with a standard transmission or can I use a manual tranny PCM with harness?

2. If you look at the picture I have a circled part of the harness in red. What is it and do I need it for my conversion.

3. Is the harness I have pictured all I need along with my 3rd gen harness for the conversion?

4. Now what wires do I connect from the LS1 harness to my 3rd gen harness? Now I know I don't need the harness coming out of the passenger side. I've just left the harness coming out of the drivers side. I need to know which of those wires will go with the LS1 harness.

I've been doing reading and searching but mostly find answers about finding the wiring diagrams of the two harnesses and that's all I need. Unfortunately I do not understand the diagrams so that is why I'm sincerely asking for anyones help. If someone could answer all my questions that would be great but I really need advice on the 4th question

From what I've been able to gather, the wiring coming from the driver's side of the dash and going into the ECM need to be spliced into the cooresponding wires for the gauges on the LS1 harness. This is where you will need the diagrams to know what goes to what wire.
You can use the LS1 wiring diagrams to figure out what wires are what. That will help you #2.
For #3, I think that is it, unless you are going to use a 4th Gen gas tank.

Hope this helps some. I've not done my swap yet, and am still working out how the wiring goes as well. Someone who's done the conversion will be much more helpfull than me (not to mention more accurate).

The plugs you have circled are the main plugs for the gauges, power to the pcm. You can find alot on shbox.com on the harnesses.

How would I work with the wire harness coming from the drivers side of the TPI? Do I have to do some splicing as well. If so, which ones?

Anyone else?

There are pins on those two connectors you'll want to use. One for the OBD-II data, one for its ground, one for oil pressure gauge, maybe others as I'm just going from memory. I also had to bring a fused 12VDC wire in (maybe two?) and add two ign-switched 12VDC outputs from my underdash fuse panel for the injector/ignition circuit on each bank.

There might be free info out there by now, I ended up buying a Helms manual for the 2001 Trans Am donor and mapping out my car's two connectors (C100, C207) the hard way.