Hello fellow enthusiasts, I recently picked up a 5.3 motor, engine harness and ecu from "Craigslist". I have started to "mod" the harness to be stand-alone, I noticed the connectors that connect to the ECU were Red and Green instead of Red and Blue. Now this is my first LS instal/Build. The connectors do not fit into the ECU. The Serial number for the ecu is 12200411, which appears to be from Escalade or Corvette. The casting number for the motor is 12567393 which from my research appears to be a LM7 5.3, so my question is what should I have for the ECU and Harness to work? And Is there anything I am missing that I should need?

Thank You - Ross




One side fits but the other does not.














LM7 5.3, 6.0 Cam, 706 Heads with upgraded valve spring, retainers.

 

They gave you the wrong PCM,ask if they have the correct one.If not,lots of them out there you should be able to trade yours off or buy one for about $50,you also need the pedal,harness and module for the DBW,again not a big deal and not hard to find if the guy you grabbed that stuff from doesn't have it.

 

You have a 99-02 engine judging by the older design DBW throttle body, so the 411 PCM can be used, but you have a 03-07 harness. You need another harness unless you feel like really modifying it, and since this is your first swap, I wouldn't recommend it. You need a 99-02 DBW harness that will have blue and red connectors and two plugs at the throttle body instead of only one like you have. You will also need the all plastic TAC module, dont get one with the aluminum base, it won't work for you.

 

I found a red/blue harness and I have started the search for the TAC module. Thanks everyone for their input, you all were very informative!