Siraj

Hello guys, I have a 2006 550i M Package, have pretty much changed everything in this car myself ( cooling system, ignition coils, spark plugs, cam shaft sensors, valve cover gaskets, eccentric shaft sensors etc) everything I use is oe or oem no cheap parts. The only thing I sent the car to the shop for was stem valves, they did the stem valves, changed the head gaskets and machined the heads ( car had no head gasket issue but we were there ), but whenever they removed the engine they missed up one of the wires for the camshaft sensor so they connected them cheap and used electric tape. I started feeling loss of power and sometimes the car wouldn't start until I move that cable around so I figured that maybe my loss of power was from that same cable as everything is brand spanking new. I open the cover in the engine bay where the IVM, DME and the simens VDO unit for acutators set, disconnect them to try and trace a lose cable ( which i didn't find any issues in there ) then connected them back, my only mistake was that i forgot to disconnect the battery when i did that. Here is the weird part, i have my traction lights on the dashboard, no check engine and transmission is in limp mode and can be shifted without hitting the brakes, THE CAR STARTS. I started it for less than a second then turned it off, connected my computer and lunched ISTA, got about 25 codes all related to DME, as the main one was no communication possible with engine electronics. Tried deleting codes but they would come roght back on as soon as I switch my ignition on. My next step was to look for blown fuses specially on the IVM box, and the IVM module is new but nothing looked burnt or blown, looked in the glove compartment and trunk same there no issues. Checked wires for corrosion or mis contact and they looked good and shiny. Started wiggling the wire harness hoping it's a loose connection but nothing changed, tried removing and reseating wires with no changes, still car starts, i let it run for 4 seconds immeadiatly fans kick in. Tried disconnecting the battery for 8 hours was thinking maybe the DME is hung or something but still same issue. Did I fry the DME unit? It wouldn't make sense because the car starts and is alligned with the EWS, is there any relay or fuse that I'm missing?

Car was running with no codes before, it had the loss of power i mentioned and would go to limp mode and hard shifting when slowing down to stops, that's why I messed with those cables.