[LessIsMore]

Originally Posted by 335e92tx

DO NOT reset throttle adaptions with bav tech or inpa cable (via mhd). Using either will CAUSE this problem. Reset it using the factory accelerator pedal method..

Check youtube

If you still get these codes after resetting TA with the accelerator then you might have a problem.

Bump for old topic! I've been searching 2CFB code and found this thread.

I think there may be truth here to above about throttle adaptation reset CAUSING the issue ...

Yesterday I cleared the throttle adaption (unrelated tuning activity). Drove fine at the time and no errors afterwards yesterday. Parked it for the night.

On cold start up this morning, I got idle surging immediately, along with a yellow half-engine error light in DIC, and the traction control and yellow 'BRAKE' light were on.
Received following codes:

2CFB - throttle valve adaption value
2D09 - Drosselklappe (this appears to mean "throttle valve" in German, but unclear on what this points to exactly)

I cleared the codes, and the engine stopped surging, and the reduced power condition and yellow half-engine light went off. Car drove fine. However the traction control and 'BRAKE' dash lights remained on.

I've started and shut down engine several times, and the surging and code always went away when I clear the codes, but always returned on start up. The car stops surging and drives fine once I clear codes, but if I shut engine off and restart, the 2CFB returned each time.

Using MHD flashing app, I did 'clear other module error codes', and when I restarted the engine this time, the surging did not return. However the traction control light and yellow 'BRAKE' light are still on.

I'm going to try the gas-pedal reset and see what happens ...

[Franzein]

Any update???

[SixBanger]

Im encountering this issue as well. Any cures?

[Tim Cuculic]

I also just started getting these errors this morning. I have made no changes to the car in 40,000 miles. I have JB4, MHD, FBO, etc.

The idle jumps from 700 to 1500 over and over. The car does not respond to gas pedal.

I used the JB4 app to clear the codes while the car was running, and that fixed the problem. Now when I start the car, sometimes it's fine, sometimes it does the idle surging thing.

I'll post an update when I figure out the issue.

2CFE Throttle valve, continuous adaptation
2D09 Drosselklappe
2CFB Throttle valve adaption valve

Oddly, my power steering also stopped working this morning. It was 12 degrees F this morning; apparently my car doesn't like the cold.

[KyleS]

Anyone have any updates on this issue? Experiencing similar issues but cannot get the car to run. It will surge power dramatically from idle to +1,200 RPM once or twice before stalling. Have codes for throttle, camshaft sensors and a shadow code for high pressure fuel. Appreciate any tips.

[VonBimmer]

Dipping in kinda late here, but I had the exact same codes, with the unresponsive throttle and surging after replacing all 4 O2 sensors and Bank 1-3 injectors.

I cleared the throttle adaptations via the key/pedal method and worked like a charm!

[Warpathof86]

For anyone dusting off this thread with a similar issue, try checking your harness connection to the throttle body. It can actually pop open when trying to remove it (it kind of separates or splits in half, exposing metal pins inside). I noticed mine was loose upon inspection due to the 2cf7 code.

[BIMMER 335i]

So, since these type of forums have helped me in so many ways with my 2007 E92 335i, I want to chim in on what SOLVED the 2CF6, 2CF7 codes (Throttle valve potentiometer 2, Plausibility to air mass) with engine light pop up, erratic idle, stumbles and shuts off at stop, etc.

I hunt down the solution for more than a year, since it was at times intermittent, but lately it got worst, at high rpm hard pulls, at low rpm pulls, basically constant.
For this topic there is little definitive info on forums of a permanent solution, so here it goes.

MANY OF THE THINGS I DID SEARCHING THE SOLUTION:

Replaced throttle body
Replaced injectors.
Replaced spark plugs NGK
New Eldor Coils
New vacuum hoses
Replaced Boost solenoids.
Walnut blasting
Have 3.5 bar TMAP sensors
Charge pipe gasket oring
Have aluminum Charge Pipe
Have tried multiple MHD tunes, including flashing back to stock
Have JB4 with MHD Hybrids Race BEF
Running BMS Meth kit

SOLUTION
I did three things.
1) The rod of the waste actuator on the Hybrid turbos that I installed were shorter than the rod of actuators of the stock turbos, and the waste gates were considerably closed at normal open position vs the stocks. So further adjustment to the length of the rods of the hybrids once there was wear on the waste gate assembly would not be possible since it would practically shut the waste gates.
So I put the waste gate actuators of the stockers on the hybrids since the rod is longer and allowed adjustment to the waste gates to close at the RECOMMENDED SEVEN INCH OF MERCURY (7 IN-HG) but leaving the waste gates considerable open similar to stocks for easier release of turbine side exhaust gases when releasing the gas pedal.
Bottom Line, the waste gates assemble wear (turbines good no smoking) will cause a BOOST LEAK that can be solved (even on stock turbos) with adjustment of the length of the actuator rods to close waste gates at 7 in-Hg. The vacuum of the system produces ~ 25 in-Hg. Once waste gates close at 7 in-Hg is that the turbines start producing BOOST and the additional vacuum needed to hold the waste gates closed will depend on the target desired.
Car came back to life and pulls hard just like when the turbines were new (they have 10k at the moment I did this).
2) Took out all four O2 sensors and cleaned with CRC QD Electronic Cleaner, and compressed air. And wiped the tip body side with cleaner in rag.
3) Using MHD, flashed DME back to stock with REMOVING MHD option. Then reinstalled the MHD BEF. (I run JB4 + MHD BEF)
4) With MHD cleared the adaptations Except throttle one.

The last two (3, 4) although easy and logical, to me don’t seem as important as the first two (waste gates, Clean O2 sensors), from these two there is data generated that if they are off it will drive the ECU(DME) crazy sending erratic data to try and control the flow of air (throttle). Obviously if a boost (or vacuum) leak is introduced through some other point, it would produce similar effects of codes.

So:
Check your Waste Gates Assembly !!! (Were Items so periodically check)
Clean or replace your O2 sensors. (Were Items so periodically check)
Check for vacuum or boost leaks. (Many potential leak points)
Re-write your DME clean. (Can do for peace of mind)
Clear adaptations (not throttle one with MHD). (Can do for peace of mind)

HOPE THIS HELPS, and HAPPY WRENCHING.

[BabyJesus87]

I just went through this issue with my buddies 335i. It has a cobb tuner. Did inlets, outlet, intercooler, catted downpipes (because stage 2+ can't delete O2 codes anymore) Charge pipe, HKS BOV, new plugs, coils, has a axleback quad exhaust, stock turbos.

Initial start up was great but there was a code. I had a small mishap doing the DPs, I screwed up and got the precat O2 sensors backwards like an idiot.So I swapped them back around.

Next start up it was surging like crazy at idle. Got p2cf6 and p2cf7 codes. Did an adaptation reset (hold down throttle pedal variety). Codes came back.

Next thing I did was take off the charge pipe and look at it, make sure the O-ring was still there and where it's suppose to be, feel around the TB for any debris. I disconnected the connector going to the TB. Since this car is like 16 years old or so, I decided to spray a little deoxit on the terminals. Doing this has helped me fix so many BS issues in other peoples cars I've worked on that are a little older. I ran the connector in and out a few times before I reseated it. Threw the charge pipe back and put it all back together. We cleared the codes, reset the ECU with the tuner and then uploaded the stock tune. next startup was legit. Took it for a ride, got up to bout 7.5lbs max in stock tune. No codes. So we decided to kick it up the the Stage 1+ FMIC 93 tune. Definitely a notch up, 15lbs of boost. Ended up having a boost leak after a few pulls (Dangit!) but NO CODES! Still was hittin 9.3lbs with the boost leak. We'll see what happens on startup tomorrow. Definitely try a little electrical contact cleaner on the TB connector terminals. Do it to all your connectors if you have an older car.