Steering problem
2004 Porsche Cayenne

I have recently purchased a pre-owned Porsche Cayenne Turbo S. I have run into a few problems but the most recent is the steering stopped working while driving. It inndicated to add coolant which i had done (with no results) and while doing so i noticed what appears to resemble a very thin twind rope and it looks like something has broken. Any information would be more than helpful.