[boliversmith]

I have a 2011 550i, and I have now had the car stall out twice while driving on the highway. I wasn't pushing it hard, I just got the initial "Fuel System: Drive Moderately" and then a few minutes later I got the "Drivetrain Malfunction: Drive Moderately" and then the engine died. In both cases, when the engine cooled down again, it started up fine.

Here are the codes I am getting: 11A204, 110001, 11A002, and 119208, 481B01, 481B02. The last time it happened, I additionally had codes 140101 and 120308.

I am assuming this is most likely going to be either the HPFP or LPFP. Does anyone have any suggestions on diagnosis beyond just replacing all the parts? If it is HPFP, do these codes give any indication of which HPFP it is, or both? Also I am thinking it could be the fuel pump control module. Could it be something else I am not thinking of? I have read some theories it could just be a bad battery too.

Also, I recently installed a Dinan stage 2 tune, could this be part of it? Dinan says no, but of course they do. It's weird to me that it runs ok after sitting for a while (at least 30 mins). It makes me feel like it could also be a computer thing. Any advice on diagnosis would be very helpful!

[boliversmith]

Ok, so I was able to catch the car dying while recording the sensors. Can you guys verify my analysis? What I am seeing here is that the fuel pump speed and fuel pressure low pressure sensor both dropped several seconds before the car stalled. The rail pressure was consistent until the car stalled. I am interpreting this as a failure in the LPFP, and not in the HPFP. You guys agree? See graph below...