Thank you all for the suggestions, I did end up figuring out the culprit tonight, a fuel line to a high pressure gas pump on the engine wasn't tightened properly and leaking. My guess is that caused both a lack of fuel and mix of air to go into the cylinders.
I apologize for the lack of updates, but
@Tapps33 and I have been going back and forth troubleshooting and I would just like to do a shout out to all the amazing help and resources he's provided!
We have figured out that the driver and passenger door modules also need replaced, as they are vin coded and the doors will not lock without them. Although the original modules will get the engine running, all the other systems have errors. Other vin coded modules are the HVAC, suspension, transfer case, lighting, drivers seat modules, and transmission. Although not all of those may need replaced, they will throw some codes and I ended up getting most of them from my original KVM and ECU donor inorder to reduce fault codes to try and zero in on key issues.
I have figured out that with the Blackbox solutions Nanocom paired with the CCF editor on 100% toggle from the Genesis website, one can edit the CCF entirely to match the LR4, specifically the split tailgate and rear AC/Heating (if you have it) now works.
I do have some minor and major questions though, pulled from the most consistent error codes:
ECU: Engine Management
B10AC - Speed Control Switch, Bus signal/message failure. Alive/sequence counter is incorrect
I feel this one may be because I swapped out switch packs for a 2014+ LR4 version (mine is a 2012). Anyone that has experience with this let me know.
ECU: Automatic Gearbox
U0401 - Invalid data received from engine control modules/powertrain control module
U2101 - control module configuration incompatible
These both Tapps33 and I believe are due to the transmission mechatronic unit / valves being vin coded, there are posts as well as my own dealership saying used transmission cannot be just swapped. There is two options, either swap the mechatronics from the donor into the old transmission (which I have not done) or pull them out and there are business that will vin code them for you. I am wondering if there is any way to code the VIN in without having to pull the transmission pan out.
NOTE: Flashing a new file using the Nanocom does not work. It cannot change the vin on anything.
ECU: Ride Level
B1A84 - Vehicle configuration data, system programming failure - is not configured.
Despite swapping to the right vin coded suspension module, I still cannot get my suspension up. I also flashed older firmware into it incase it had been updated for an AMK compressor
ECU: Airbags/SRS
B0090 - left frontal restraints sensor, bus signal/message failure - invalid serial data received.
This is more a "my Rover" specific problem, but is this the impact sensors or something in the drivers seat I need to check?
ECU: Body Control
B112B - steering wheel module, bus signal/message failure - missing a message.
Possibly the steering wheel switch packs again?
ECU: Body Control
U025D - Lost communication with front controls interface module
Not sure if this refers to the console controls, as those are vin coded but not swapped
ECU: Transfer Case
U0415 - invalid data received from ABS control module
This confuses me and any help would be greatly appreciated as the ABS and transfer case modules are from the same donor but have code issues between them.
ECU: Keyless Start
U2100 - initial configuration is not complete
Not sure how to resolve this one as all key modules are replaced.
Finally, has anyone upgraded to aftermarket taillights, LED blinkers, or facelifted headlights before? I have B1247,B1248, C111A, C111B errors all for lights that I have replaced with LEDs and it reads "general electrical failure - circuit short to battery or open". Just want to confirm.