Ive got a 1999 LQ4 harness and just noticed that the PCM that came with it is listed as a 1999-2000 Ls1. They both have the Blue/ red connectors.

Should I just buy another PCM for a 1999-2000 truck or Repin the harness for Ls1 or can I use the 2001-2004 411 PCM.

Thanks for the time.

 

Should be the same service #. The calibration will be different. Shouldn't be a problem for any competent tuner.

 

So you would buy one with right service number instead of reprinting the harness. Do you know if the 411 pcm is best. I believe its the sameppin out just faster.

 

411 is same pin out, just swap PCM's and get it tuned for mods . It's not so much the PCM that's at fault for the 99-00 trucks, it's more of the operating system. But a good tuner should be able to take care of you.

 

sounds good. Looks like 100$ on Ebay will get a 411. There isn't any diffence in the return vs returnless fuel lines in the 411 are they. I can think of much difference in an 99 to 04.

 

The pcm makes no difference in fuel lines, but injector flow rate is setup different in the tune,

 

No need to swap PCM.

Just change the calibration to the 2002 operating system.

 

It does have a different service 1999-2000 Ls1 9354896
and the 1999-2000 Trucks have a 9"2"54896 and the pin out is different.

It doesnt look like a lot is changed on the pin out. Im just running the engine in a Jetboat so Im gonna try to repin the sensors to match. Then disable VATS and trans/other codes.

 

If I change the calibration on a bench top harness, is that gonna alter the pinout inputs to PCM?

 

IAT, MAP & TPS +/- pin locations are all that need repositioned to have a 1999-2000 truck harness match the 1999-2000 car PCM pin out. With only stand alone engine management running. No trans, egr,fuel pump. Just bare bones o2s, injectors, cam, crank, pcm power are all the same. 5 pins to move. Even the IAT + was the same location.