[itspeat]

This is a major doozy. I really need some help. I have a 2020 M340i giving me issues. Not sure if BM3 related, DME related, FlexRay interference, or something else.
Car has Pure800, CSF Race X Manifold, BM3, Bench Unlocked, and was slated for PI with Reflex+ until now.

Instant Limp Mode - Throttle Angle >82%
Whenever I give the car enough pedal to request >82% throttle angle the car goes into instant limp mode and stays in limp mode until I turn off/on again. Throttle plate goes into emergency 6% angle mode. Then it will drive perfectly fine again, as long as I keep the requested throttle angle less than 82%. No issues whatsoever until that point. I can drive for hours without issue as long as I don't push the pedal too far..

At first, I only thought that it only happens while driving. I noticed that less than a second after throttle angle hits 82%, car cuts power, and I get a bunch of DSC + Differential drivetrain errors (wheel torque request missing, actual wheel RPM missing, vehicle speed missing, Rear Axle Differential Lock). It seemed like the entire FLEXRAY bus was crashing. I thought it was wheel speed sensor, DSC module, or something related to the drivetrain... it isn't.

Car also had XHP but it happened in Stage 0 and Stage 3 maps, so I uninstalled it. No luck. Same issue no matter what.

Codes While Driving:

- 10D000 Combustion Engine: Torque Limitation Active

- 030DA8 Battery condition detection DSS-Li-Ion: Serial Number not the same after battery replacement

- 100227: Throttle valve, activation: Short circuit

- D35DC3: Signal (wheel torque drivetrain actual, 61.1.2) invalid, transmitter DME/DDE

- D75511: Signal (ECBA status, 43.1.4) invalid, transmitter DSC

- D7553D: Signal (DSC stabilisation status, 47.1.2) invalid, transmitter DSC

- D75585: Signal (wheel torque, drive 9, 41.1.2) invalid, transmitter DME/DDE / CCU

- D7558D: Signal (wheel torque, drivetrain actual, 61.1.2) invalid, transmitter DME/DDE / CCU

- E05614: Signal (chassis, direction of travel) invalid, transmitter VIP

- E05618: Signal (chassis, acceleration data) invalid, transmitter VIP

- E0561A: Signal (chassis, steering angle) invalid, transmitter VIP

- E0561B: Signal (chassis, vehicle model) invalid, transmitter VDP / DSC / AHM

- E05620: Signal (driver assistance, convenience function and safety function) invalid, transmitter SAS / VIP / BDC-ZGM

- S 0751: Permanent SAE fault codes stored


BUT I am able to run the throttle adaptation function using ISTA, ProTool, and BM3 and I can hear the throttle moving. I can also SEE the throttle plate moving when I remove the charge pipe and blip the throttle in Park... so I know it is getting power and working as expected.. I even replaced the entire throttle body assembly.

Still Happens in Park
Then I realized that if I request throttle angle at >82% for long enough in Park, it would STILL go into limp mode. But with only two codes... none of which are related to DSC, VTG, etc. So that ruled out any wheel speed, DSC, Transfer Case, Differential issues.

Codes with car in park, when I request >82% throttle angle:
- 10D000 Combustion engine: Torque Limitation Active [Inactive]
- 100227 Throttle valve, activation: short circuit
It does this on Stock Tune, OTS Stage 2, Custom Paul Johnson Maps.

Logs:
In Park: https://www.bootmod3.net/log?id=65e8...f977020244e749
Driving: https://www.bootmod3.net/log?id=65e7...bf8d6994ce28e9

Workaround Solution
I had a random idea for diagnostic purposes... I flashed my own map but I only changed one table... I lowered the values in the "“Full Load Throttle Characteristics %” table from 97% down to 80%. Now the maximum throttle angle was limited to 80% even when the pedal was pushed to the floor. CAR STOPPED GOING INTO LIMP MODE. It drives fine...

If the throttle was truly faulty, wouldn't it still go into limp mode? What happens once the throttle tries to open more than 82%? Why does the car freak out? What changes logic wise?

I feel like this is a tune/BM3 issue? Like something that ProTuningFreaks may need to fix...

[itspeat]

Album with overview of FlexRay bus, codes, ISTA screenshot: https://photos.app.goo.gl/pZanzjGvTAdSpTdM9

[itspeat]

Throttle Code in ISTA


Codes in Park:

[itspeat]

Interestingly, according to ISTA, the throttle angle % is reaching 98.82% when the issue arises... but BM3 only shows it maxing out at 82% so that is interesting. Am I able to uninstall BM3 without need to re-bench unlock?

[mike@x-ph.com]

Originally Posted by itspeat

Interestingly, according to ISTA, the throttle angle % is reaching 98.82% when the issue arises... but BM3 only shows it maxing out at 82% so that is interesting. Am I able to uninstall BM3 without need to re-bench unlock?

yes you can go back to the stock map, it wont lock the dme

[itspeat]

Originally Posted by mike@x-ph.com

yes you can go back to the stock map, it wont lock the dme

Gotcha. Yea I did flash the "Stock Map" option but wasn't sure if that still had BM3 related code since it seems like I can still tweak some settings, even with that map flashed. And if it's a BM3 related issue, wasn't sure if it would still mess me up... if this turns out to be a bad ground (I've checked them) then I'm going go to lose my marbles lol.

[itspeat]

bump. Not sure best way to diagnose DME or FlexRay if it turns out to not be a BM3 thing

[B58-M340iX]

I've had issues with shadow limp mode for some time. Basically, on the S2 e50 or S2 Multimap, the car would go into limp mode and gimp itself for whatever reason. I'd have to shut the car off and turn it back on again for it to have full power. I have logs of this torque limitation issue happening where I'm in WOT and then the throttle angle changes to below 90 then 80 (etc) although I'm still in it.

I reached out to BM3 support and worked with Halim on a test map to remove torque limitation issues. The test map has removed all of these torque limitation issues. He's supposed to push these updates out to the map this week (I haven't seen the map versions change yet, so I'm not sure if they were pushed). Hopefully, these torque limitation fixes will resolve the issue you're having as well.

[itspeat]

Originally Posted by B58-M340iX

I've had issues with shadow limp mode for some time. Basically, on the S2 e50 or S2 Multimap, the car would go into limp mode and gimp itself for whatever reason. I'd have to shut the car off and turn it back on again for it to have full power. I have logs of this torque limitation issue happening where I'm in WOT and then the throttle angle changes to below 90 then 80 (etc) although I'm still in it.

I reached out to BM3 support and worked with Halim on a test map to remove torque limitation issues. The test map has removed all of these torque limitation issues. He's supposed to push these updates out to the map this week (I haven't seen the map versions change yet, so I'm not sure if they were pushed). Hopefully, these torque limitation fixes will resolve the issue you're having as well.

Thanks! This makes me feel a little more optimistic.
I am really hoping this is something that BM3 can sort out.

Do you have any logs from when it was going into limp mode? I think it's so weird that this M340i shows the throttle angle % flatline at 82%. Almost like the DME doesn't want to open is anymore. And when it tries, it just... crashes.

I honestly don't think it is a wiring or Flex Ray issue.
Was your car throwing any throttle body codes like mine is?

[itspeat]

Well, figured I would mark this problem as solved in case anyone ever runs into something similar.

There was an issue with the manifold. The metal plate that was welded inside of the manifold was not in the correct position. It was too close to the throttle body and prevented the throttle plate from opening 100%.... explains why the 82% throttle angle issue occurred at the same angle every single time. I KNEW it was too consistent to be an intermittent electrical issue... especially after tracing the wires multiple times and pulling the manifold out at least 5 times. Really thought I damaged the harness, DME, FlexRay bus, potentiometers in the throttle or something else.

I was so close to giving up and accepting that this car would not be able to race at Bimmers vs the World... and then I decided "F it" and opened the throttle by hand to see what would happen and then the realization hit me like a high-speed train.

I now know WAY too much about the inner workings of the throttle bodies, buses, and pinouts on these cars

Hitting the metal plate


Prior to trimming the plate


Trimming the plate


Able to open all the way

[prostcfc]

Thanks for writing the final chapter; so annoying when someone solves an issue, but doesn't update their thread!

So, seems like a manufacturing issue with CSF then? Doesn't look like you cut out a whole lot.

[B58-M340iX]

Glad it was an easy fix for you! I'm still waiting on BM3 to do the map updates

[itspeat]

With how much heartache and headache it put me through, I felt very strongly about not leaving this thread hanging just in case someone else has equally poor luck and ends up in a similar situation with no one to help them troubleshoot lol.

But thanks fellas! Yes definitely an unfortunate manufacturing defect with this unit. Not sure how many are really impacted by it.

B58-M340iX... i wish you the best of luck.