Here's an interesting follow-up to an earlier post. Last week I had a warning that I had a "STEERING FAILURE" so I pulled off, shut the car down, and re-booted the black box. but just after start-up the same message appeared. Checked the power steering fluid and it was below the stick. Initially I could see no leaks on, around ,or below (on the floor of the engine compartment). Went to my dealer, got proper fluid and filled the reservoir, made an appointment to find the leak. Before returning to dealer, I jacked the car up and did notice a small wet area on the bottom of the 550i, just below and behind the right front wheel.
Dropped the car off and a day later get a call saying there was a leaking tranny gasket which was replaced! I said thats great but what about the steering fluid loss and steering failure message? They said no leak was found!! Interesting no? I asked them to check the radiator coolant thinking that if there was a water to fluid cooler for the steering pump, that there might be an internal leak but all was well with the coolant. My guess is that the reservoir was under filled at the factory and a small amount of air was in the system and after a while it self bled and dropped the fluid level enough to flag a warning. Anyone got an explantion? My 550i is a 9/05 build with 3,300 miles on the clock.

 

Most likely your right if you can't find any leaks.

 

Where did you check the power steering fluid? Can you tell me where is the exact location of the power steering fluid reservour?