Drivetrain Malfunction / 120308: 0X120308 BOOST PRESSURE CONTROL error code...

[miltolam]

Group, I have a 2011 F10 xDrive. Just recently while cruising on the highway in Sport mode, I got the "Drivetrain malfunction" message and the car goes into limp mode. I did a Bimmerlink scan and this is what I'm getting for info memory (see screenshot of report in photo below). I'm guessing that the motor error (120308: 0X120308 BOOST PRESSURE CONTROL, PLAUSIBILITY: PRESSURE TOO LOW) pertains to this problem.

Can anybody give me more information regarding this issue? Is this common for the N55 and is there a way to better diagnose the problem before I take it to the stealership? And lastly, until I am able to get it checked out, if I keep it in Normal mode (2011 doesn't have "Comfort Mode") will I be doing any disservice to the the car by driving it? Thank you in advance for all your help.


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[tenken1013]

Not a car expert but I had a similar issue and I had to replace my turbo.

[White94RX]

Don't use the term "stealership". It's forbidden on the forums. There are a ton of dealership tech's, and other employees, on this board (with a vast wealth of expertise, knowledge, and experience) that you have just insulted (myself included). I know what's wrong with your car, and I could help, but I don't think I will. Good luck.

[Trainwreck914]

hey white94rx, I just picked up a 2011 535i m sport. i have the same code stored in memory, but i am not getting the drivetrain malfunction message. Can you give some insight please? I'm sure many more would benefit from your wisdom, than just the op or myself. I've searched the internet but have come up empty handed.

[White94RX]

If it's stored in the memory, and not currently present, and you don't have a check engine light or drivetrain malfunction, then don't be concerned with it. Just drive your car and enjoy it. If it comes back at some point, then some diagnostics and inspecting will be needed.

[bmwtaolee]

Hi White94RX. I'm hoping you can answer another question about the Drivetrain Malfunction notice on my 2015 535i. I am also getting that notice and my check engine light and caution light both sometimes light up and sometime don't. In the fault memory, my car is showing "Charging pressure control: Switch off as consequence," "Electric wastegate, learning limit position, cold start: malfunction," and "Electric wastegate, learning limit stop: stop position (wastegate closed)...".

A tech checked out my wastegate and said it was operating fine so he wasn't sure what needs to be fixed. Do you know what is going on or what needs to be serviced?

Thanks!

[White94RX]

If the wastegate actuator was operating fine, it wouldn't be storing fault codes. It needs to be replaced, and adjusted properly. There's a test plan in ISTA that checks the adjustment after it's been replaced.

[Jimincalgary]

First Post!

thought I’d post even though your problem may be solved already.

I had this same issue and from my research it would be a vacuum leak. It was intermittent. So I went looking for one.

It was suggested there is a Vacuum crossover hose (it’s about 1/4” and rigid) that went from a vacuum pump low on the drivers side of the engine up over the valve cover. I found that hose and ensured it was tightly connected on both ends. I may have bumped it loose when it did the oil pump housing gasket.

I also found that the crankcase vent hose from the valve cover to the intake pipe (that runs alongside the passenger side of the engine) was broken (hairline crack). This pipe is a corrugated black flexible plastic pipe that obviously deteriorates (gets brittle) from the heat of engine. It’s about 4” long.


I could tell it had been removed by the BMW dealership when they replaced my radiator. If fixed it temporality with a chunk of 3/4” (or 7/8”) heater hose after removing the corrugated plastic pipe from the fittings on either end and replacing that stuff with the hose. This held fine for a year until I could order the replacement part on AliExpress to save a ton of money. I suspect the heater hose would be a more permanent fix than this dodgy factory plastic material but I have some left (which I keep in the trunk with some gear clamps should it ever come up again).

I hope this helps someone.