I wanted to update on this post. I have an 2011 C70. Issue Now resolved
Final issue was 2 items.
- Power module failure . I had to replace before full diagnostics. Sensor are in series ( like old Xmas tree lights). If one sensor does not work all the ones behind it will not work.
- Also will need ...

Update -I found an experienced retired Volvo tech. My issue was a hydraulic failure. It seems that the two solenoids on each side of the hydraulic pump has some corrosion due to moisture that needed to be cleaned and reseated ,then re-calibrated.I will let you know how it works out

The Hydro release cable is not under the rear seat in 2011 C70. Pulled the seat out had two friends to assist with roof but no cable.
I cant not find any document that tells the location of this cable.
If anyone knows cable location please chime in.

I am working on a solution what was the approx pricing for fix. Is there a cable under the rear seat if not where is it?

I don't have an answer, I had the same issue happen to me. I did get a chance to download some C70 top info. I have attached
I am reading to see if there some info for me to resolve this issue