siavosh

I upgraded all the engine management controllers last week using winkfp and I thought it all went well. I had a backup battery and a tenderizer connected to the car while doing that to be sure I won't lose voltage but after the upgrade, there are several problems I'm facing:
1. I have active steering fault and the steering is extremely stiff. Almost impossible to turn when the car is standstill. I have tried to initialize it by turning the wheels lock to lock but it didnt help. After that I hooked it up to inpa and saw that there is no read from the angle sensor. Tried to restart the CPU, which is successful but doesn't initialize or bring back the reading from the sensor.
2. After upgrading I have a airbag and restraint system malfunction. Thecodes are "interruptions in the trigger" and I'm not able to clear them in inpa. They just come back. The fault is for every seat except driver seat.

On a side note, the previous owner had installed an ACDelco battery on the car (I know...stupid and cheap of him) although I read a healthy voltage from the battery (around 12.5 with the car off) but I have a feeling that this is all coming from a bad battery and I've read so many threads about crazy stuff that BMWs do when they have a bad battery.

So gimme your thoughts boys! What should I do? I have also tried reprogramming the modules in case the software wasn't installed correctly.