I have a similar problem with my 2011 x5 though with 34000 miles. I get a reduced power display however when I slow down it goes off. Had it to the dealer with no luck.

I would like to make a comment about fuel temp and cooling. I own and operate a fuel injection (Bosch Authorized) and vehicle repair business for the past 28 years. Since the change to common rail diesel systems fuel temperature is a big issue. BMW, Ford, GM really does not matter. They all use almost identical Bosch fuel systems. With pressures in excess of 30000 psi now days the fuel get very hot very fast. Many vehicles including all the new domestic diesel have "fuel cooler" on them. The Dmax has what looks like a little trans cooler on the frame by the tank. The diesel fuel is used for cooling, while it is not a good heat transfer agent it still is used to take heat away from the injectors and pump system.

There are some people that like to as I term it run on the top half of the tank and those that run on the bottom half all the time. We see way more problems with the fuel system on customers vehicle if they are the "bottom half" kind of guys. 10 to 18 gallons for fuel will absorb and dissipate way more heat than 4 or 5 gallons. It also takes much longer to heat up 10 to 18 than 4 or 5. We have had vehicles in our shop in the middle of summer with a 1/4 tank of fuel on the guage that you cannot hold your hand on the bottom of the tank because it is so hot.

I am not a chemist but I think diesel fuel tends to break down and oxidize when it gets to a certain temp. We have seen this in high hp ag engine used in harvesters. Actual fuel breakdown when an refinery missed putting in a temperature stabalizer additive. Over 200000 worth of damage fuel systems from 2 semi loads of "defective" fuel. Turned to a brown sludge.

Anyway I started a new post on the "reduced power" display. Would appreciate any help out there.

Thanks