F80 M3 DME + FEM + DKG Fault Codes

[septavus]

Bought a salvage flood effected 2015 F80 M3, to turn into a racecar. Previous engine bent some rods with water in the engine. Have had to swap the engine with another S55, which turned over when installed and tested. No water damage visible in interior of the car, no anywhere really (other than in the engine). My working assuming is water was sucked in the intake when previous owner tried to drive through water.

Since that point I have systematically replaced upgraded most of the car front to back. The suspension (Nitron R3), Full mishimoto cooling package (DCT, Oil, Heat Exc, Intercooler, Charge Pipes), Mosselman Thermo. New TBS Brakes and Discs to go down to 18" wheels. Basically everything but the turbos and flex fuel.

The car starts, runs, drives forward and back. I've cut the muffler out and have VRSF Downpipes and a cat delete. (Full race car)>

My problem is I'm getting 100+ codes. Primarily communications errors on CANBUS. FlexRay, PTCAN, PTCAN2 Between the DME, ICM, FEM, DSC & DKG basically all the important things.

I'm wondering if I have an issue with my FEM module / DME either from water damage or a short. I've checked and reseated all connections, nothing looks broken or corroded. While I'm mechanical, I've yet to use ISTA, and was wondering is this sort of issue is more coding that electrically usually? Is there a reset function, update etc?

Having access to newtis, I've looked through the wiring diagrams between most of those systems and was able to check each connection that way physically.

I've searched the forums, and one thread I found for a racecar build with similar issues said "I had a blown canbus feed from the FEM body module, which was easily rerouted". But no specifics on how to fix. I've also seen on the forum that the FEM can fill up with "shorts" and need to be reset or something of the like. With my limited knowledge, it sounds very simlilar. Now I can upload every fault code, but there are quite a lot, but the common thread between most of them seems to be FlexRay, PTCAN, PTCAN2.

I have another FEM, DME, and Key. from a friends car which he kept. I was thinking of swapping the FEM to see if it would clear any faults. However before I do that or the DME....

Any thoughts, or guidance?

[Track/S]

You need a remote coder who can check the problem, but I think the FEM has been flooded.