yes ive come finally to this conclussion also theres almost nothing out there for aeg, and the little that there is is shrouded in cryptic mystery or gatekeeping. when i started this build a few years ago, there was alot more info outhere. I ran and still run a aeb 5.9.2 wich is why i choose the aeg in the firstplace. something changed with the internet since 2019 and all those great walkthrews for begginers and deffinition files for aeb 3.8.x and 5.9.2 are all gone or unsearchable. I cant even find info on how to simply flash one of these ecus , i get partial info good enough like "power to pin 43" . im am looking or was , for noob level info. stuff i can read and learn. i clearly wasting my time, going to get standalone i think as the community has some sort of restriction on it that i don't understand how to get around. example on ecuconnetions i dont have permission to to "view attached files" and i cant figure out how to get this permission.
I'm not trying to be rude, the fact of the matter not too much information publicly exists, any development done was from someone spending hours if not days making a suitable definition and testing in car. Do you really expect someone to hand it over for free? The ONLY aba and aaa obd2 definitions that exist are ones that Ive posted, and again NOTHING public exist for them before that. Also, none of the definitions or walkthroughs are missing, they are all still there, and if you can not download any files from ecu connections odds are you do not have enough posts. Also, you need to be a exceptional member to download files from specific portions of that form. The way you get that status is by helping other members and actually contributing to the forum.
As far as flashing these ecus its simple, google m5.9.2 mpps pinout and you will easily find the pinout to flash it on the bench. It's been covered here a handful of times, if you need to search for a specific topic, use google to search the topic and type "nefmoto" after and you will find more results from the forum. Switching off the immo requires reading out the eeprom with some kind of chip burner, you may be able to use a clamp or probes to read it out too, but I personally just hot air them. If you find an original from a 98-99 manual beetle they do not have immo and will start without touching the eeprom. Emissions can be switched off with codewords, however readiness will still show incomplete, additional mods need to be made to set readiness. Fueling calibration is the same as any other m3.8.3 / m5.9.2 its been covered several times.
If you are planning on swapping the management why not just go with me7? I mean besides swapping the throttle and throttle pedal its the same amount of effort as swapping m5.9.2, and you can use the the ignition coil from the avh/ azg / bev / bbw. The me7.5 comes with a factory wideband ecu, and has boost based software versions. Ive actually swapped a subaru to run a 1.8t ecu, it would be a lot easier on a lot of levels.
Lastly I just want to add, the amount of people that can actually custom tune a m5.9.2 setup in the states is about 5 or less, most just flash files others have made. If you have any specific questions like map locations I can help you with that. Per the forum rules its required to post the original file when asking for definition files. Its kinda hard to help you if you can not provide the bare minimum on your end...