I think Josiahg52 is right; even one dead TPS sensor will trigger the malfunction message. Sensors are part of each inflator valve. There is a nut that holds the valve stem to the wheel; unscrew the nut, then pull it into the wheel. Obviously, the tire bead needs to be broken down from the rim. Your can replace them one at a time, and see when the system comes back; or just replace all 4. Get them online, much cheaper than thru BMW. Just make sure you get the correct ones for your year; I think they changed sensors around the 2012-2013 time frame.