Hi, I recently changed my transmission conductor plate on my 1999 e320 with a part from Amazon, brand listed as "Mercedes Benz." Got the part, and it seemed the Mercedes label may have either been scratched off/ was not present, and it did not come in original Mercedes box. After careful installation (making sure the plug is seated properly) it still is in limp mode and has the check engine light.

I also bought Carsoft v12, which seemed to work well with my super old Dell d600, I cleared the error codes, which were basically all related to solenoids. After a few minutes, the codes would constantly reappear. So I figure the plate is defective and must be returned to amazon.

BUT, before I do so, just wondering if it could be something else, like the Electrical connector/harness or the TCM? What's the best way to diagnose that? Could return the plate, get a new one, and go from there. TCM did seem dry, but who knows.