While on my way back during a long roadtrip I got an error message on the idrive screen - "Driving Stability - Drive control systems malfunction. Reduced driving stability in curves. Drive moderately!" The error message goes away when I turn off the car but then comes back about 45 minutes later.

I'd like to just check the power steering fluid level but I can't seem to find the reservoir under the hood. Nothing is indicated in the manual as far as I can see. I've narrowed it down to the ATF reservoir, but isn't that Automatic Transmission Fluid, not steering fluid...right?

I called a BMW dealer and they just told my it's likely a sensor and not to be alarmed. I'm nowhere near a BMW dealer to have it looked at, so I'd like to just add a bit of power steering fluid to see if that's the answer.

Any suggestions

 

I would also say it's a sensor problem.

Had a similar warning for the driver airbags - it was a sensor malfunctioning.