Power steering stop work after heater core replace

I replace the heater core on my 03 Jetta TDI the power steering became hard noise and some oil did come out from the reservoir lead I have a error code on the vcd 00778 - Steering Angle Sensor (G85)
005 - No or Incorrect Basic Setting / Adaptation

I was I reset the clock spring by following the procedures on Ross Tech website but it did not fix the problem on the power steering. Is there any electronics on the system? how can I troubleshot this? I believe I must disconnect something on behind the dash because it was working fine before I replace the heather core and radiator. Any help would be appreciated
thanks

If you had a steering angle sensor code you also had the abs light and the circle with the triangle light, lit on your dash. After resetting with vcds did those lights go out?

Yes light went off and no codes but the power steering had no improvement

This is very strange I was looking the power steering reservoir it was very low I add over 10oz of fluid it working now but it makes no sense. Before I start to work on the car the power steering was working fine I can't find no leaks or wet spots any were. Any ways I am glad to have the car running again.