I am doing this project for my wife. The victim is a 2012 Equinox LTZ 2.4L. The donor vehicle is a 2013 Buick Regal Premium Turbo. I went with the 2013 Regal because it seemed like the easiest swap, having the 2.0 LHU and the 6T50 auto transmission (6T45 trans in the Equinox). I verified pin locations through ALLDATA for the Equinox E39 and the E39A for the Buick. I decided the easiest way for me is to dissect the harness from the LHU and add the sensor/boost solenoid wiring and pins to the absent locations on the Equinox connectors. Most of the LEA harness connected directly to the LHU as if it were meant to be. The o2 sensors have different connectors, so my first question is, couldn't I simply swap the o2 sensors from the LEA to the LHU? If I remember correctly, it was the LNF that had wideband o2s, but not the LHU.
Another thing I noticed is related to the fuel pressure sensor. On the LHU, the fuel pressure sensor is pinned at locations 2, 8, and 21 on the X1 connector. On the LEA, the fuel pressure sensor is connected to the fuel pump control module. I'm not sure why one feeds directly to the X1 while the other goes to the FPCM. I guess in the end, it's all being communicated one way or another?
Low oil level sensor. The Equinox does not have a low oil level sensor on the oil pan (how dumb is that?), but the Regal does. I pinned that out as well, but since the Equinox never had one, will that even work? Doesn't that signal get passed to the BCM to report on the dash?
Lastly, the ECM. Which to use? I have both and downloaded both files before taking everything apart. If I run the Equinox ECM, I could get a tune on it, but then what will I need to do to get the transmission to function properly since it came from the Regal? I do know the TCM is the same in terms of a replacement part for the 6T30-6T50. On the other hand, the Regal ECM is already programmed to run the engine and transmission, but I'm sure the Equinox BCM will have a problem with it. This is new territory for me, so I appreciate any advice or support on the project. I'll keep this updated and share the information I found if there's actually any interest in it.