Need help! 2FBC code

Ztuck45

Private
May 16, 2017
32
37
0
Ride
2010 335i
Alright guys, I’ve got a problem that i am literally lost on. The car keep throwing a 2FBC (fuel pump control valve signal). The code will show up intermittently, sometimes i can clear it for a while and sometimes it pops up immediately after.

I’m running the vtto double shotgun kit (i don’t think this is related) and i also JUST replaced the hpfp with a brand new one and codes continued to pop up. This leads me to believe it’s an electrical problem.

This problem started after installing my Doc Race intake manifold. One thing that happened during the install that makes me suspicious was i accidentally touched the starter with a piece of metal that cause lots of sparks . Im wondering if that caused something to cause the code to show up, possibly??

Any input would be appreciated!
 

Jeffman

Major
Jan 7, 2017
1,620
1
629
0
Sounds like something got fried. Have you tried diagnosing with Rheingold or ProTool? That would be my next step if this happened to me.
 

Ztuck45

Private
May 16, 2017
32
37
0
Ride
2010 335i
Sounds like something got fried. Have you tried diagnosing with Rheingold or ProTool? That would be my next step if this happened to me.

Do you think a bad dme could cause this? I don’t think it has anything to do with the shotgun kit since yesterday i drove around with the primary pump unplugged and only using the secondary and i got the code after 20 mins of driving.

I do have pro tool but I’m not sure what to look for when diagnosing it
 

Jedi135i

Lurker
Nov 5, 2016
24
10
0
Margate, Fl
Ride
2009 BMW 135i
Is there any update on this? I am getting the same code, I changed the HPFP to a new one. That didn't change anything. I tried the fuel rail sensor and that is fine. Can't even get to drive the car long enough to do a Log.
 

carabuser

Lieutenant
Oct 2, 2019
894
1
801
0
UK
Ride
Z4 35i & 335i
2FBC is triggered from 3 different scenarios. VCV current being too high or low, VCV position adaptation being too high or low and the VCV current adaptation values being too high or low.

If you have an altered high pressure pump then you are altering the flow characteristics of the pump and the VCV will probably see greater fuel mass at lower VCV duty cycle and the VCV is reaching the limits of how much it is permitted to adapt. This will be made worse if you use a JB4 since the DME had incorrect fuel mass values as a result of the false boost reading.

Ideally you would monitor which condition is causing this error then monitor the process variable responsible for the error and tweak the setpoint accordingly. I have a feeling that it's caused by one of the minimum values since upgraded fuel pumps would mean the maximums are less likely to be touched.

Get your tuner to lower the values in C_CUR_VCV_BAS_AD_VCV_PLAUS_MIN, C_FAC_CUR_VCV_PLAUS_MIN and C_CUR_VCV_MIN_AD_VCV_PLAUS_MIN and that should prevent the error occurring.
 
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Jedi135i

Lurker
Nov 5, 2016
24
10
0
Margate, Fl
Ride
2009 BMW 135i
2FBC is triggered from 3 different scenarios. VCV current being too high or low, VCV position adaptation being too high or low and the VCV current adaptation values being too high or low.

If you have an altered high pressure pump then you are altering the flow characteristics of the pump and the VCV will probably see greater fuel mass at lower VCV duty cycle and the VCV is reaching the limits of how much it is permitted to adapt. This will be made worse if you use a JB4 since the DME had incorrect fuel mass values as a result of the false boost reading.

Ideally you would monitor which condition is causing this error then monitor the process variable responsible for the error and tweak the setpoint accordingly. I have a feeling that it's caused by one of the minimum values since upgraded fuel pumps would mean the maximums are less likely to be touched.

Get your tuner to lower the values in C_CUR_VCV_BAS_AD_VCV_PLAUS_MIN, C_FAC_CUR_VCV_PLAUS_MIN and C_CUR_VCV_MIN_AD_VCV_PLAUS_MIN and that should prevent the error occurring.
Good Morning Carabuser,

Thanks for your explanation, it's the best we've had on the code. The high-pressure fuel pump we installed was a new OEM, the one that we took out was new also. Last night a friend of mine mentioned adding gas to the tank since we were currently at 1/4 tank. We added gas did a few pulls and realize the car was no longer surging or cutting out after WOT(the car only cut off or surged after we let off the gas). So now it no longer does it. The car drives fine and operates fine. I did see the code there still though. However, we added a full tank of gas last night but the car says 3/4 we couldn't add anymore since it started to overflow, so I believe we have a bad fuel level sensor, would that cause the code? Also, could it be a bad sending unit? Also should after this reply, should I still contact the tuner about changing that parameter you mentioned?