[Weenie144]

Hey guys. Recently acquired a 2011 535i F10 6MT and discovered a pretty serious problem after a couple months of ownership.

I installed an MHD wifi adapter and full license for diagnostics and live monitoring if anyone is capable of reading graphs for me. It would be greatly appreciated if you could accurately diagnose the issue with the given resources.

For the first month the problem occurred, it would only affect 3rd and 6th gear. 3rd would discontinue acceleration at 3,800-4,000 RPM and lose all turbo pressure (opening the wastegate and locking the RPM at that exact range every time) I could temporarily accelerate further by repeatedly stomping the throttle pedal 2-3 times and it would continue to pull.
6th gear is perfectly okay until I meet 75-80MPH, in which it also succumbs to the same fate.

Here recently, it has began to affect 2nd and 4th by hesitation in power (taking a second or two to find the power after initially stomping the throttle)

I've even received Drivetrain Malfunction error messages through my iDrive display.


The only sort of error code I receive through my OND scanner and MHD app is (119201, low pressure fuel sensor short to B+)
I'm not sure if this is the issue, since I've googled the problem and many have found the lacking pressure of this sensor in N55 platforms. Maybe my 2011 is the odd man of and includes this sensor, but I'm not sure.

Could this just be the HPFP, LPFP, or even just a clogged fuel filter?

ANY feedback or information would be greatly appreciated as I'm completely stumped. I really don't want to just take a guess at repairs and start dumping thousands in fuel related parts, so please submit any comments or information you may have.

[95blkmax]

IIRC that code means that the pressure being put out by the LPFP is too low in relation to that of the B+ circuit's voltage (what feeds the EKPS and tells it how much output is needed from the pump).

What sucks about diag'ing this pressure situation is that early F10s did not have a low side fuel pressure sensor. All pressure info is derived and assumed by the DME from the output values to the HPFP and EKPS, and the PSI reading of the sensor on the fuel rail.

I can tell you that given the age of your car (same age as mine), it would not be unusual for your LPFP to be on its way out and it can't feed enough PSI to the HPFP under the load of higher gears.

In the logs that you have, do you have one that shows the exact moment when this behavior takes place? I'd like to take a look at that.

[95blkmax]

your PMs are not able to get replies Weenie