[svagusta]

Have a 2011 335i 90k miles FBO with PS2 and xHP trans tune that I have owned for about 4 months

No previous problems with the transmission, car would pull hard and never experienced slipping.

Recently went to the dealer to get footwell module replaced under warranty. During replacement they tried to update software on all the modules (standard with service visit) and could not connect to transmission - likely because of xhp tune. They contacted BMW corporate who told them to go ahead and replace mechatronics unit under warranty and retry. Since car has 90k on it, I did not object.

So after I got the car back I reflashed MHD tune, but not xHP right away.
Drove the car maybe twice, and not hard, but still started to experience some slipping. Chalked it up to not having xHP tune to firm up gear changes.

So I just reinstalled xhp stage 3 and got on it about 60% throttle, the 4th-5th gear shift failed and then TCM warning lights come on and safety mode kicked in and i limped home. Surprisingly xHP didnt find any fault codes, but DME threw these error codes

3BD8
3BDD
3BE1
CD8F

I couldnt find much info on these codes, but they all seem to point to a lost signal from the TCM, as opposed to a fault code in the TCM. Anyone experienced these before? Don't know whether to look for a software or hardware problem.

[Supermoon]

Message directly to xHP on facebook. They got back to me in a few hours.
I'm surprised they covered a MY2011. Do they have an extended warranty on the footwell module?

[svagusta]

xHP has responded and are looking into it.

Yeah, FRM is warrantied for 10 years. I just made the cutoff - April 2010 build

[svagusta]

still working with xHP, but I really doubt it was caused by the flash. has anyone experienced these codes before?

[svagusta]

xHP seems to think the problem is with the transmission adaptation values. I did not reset adaptations, but it certainly does seem like they've been reset - and I am betting the dealer did so when they replaced the valve body, which is probably the right thing to do.

But now what do I do? I'm afraid to give even 50% throttle.

I have seen the infamous document floating around about the "Relearn Process" after resetting adaptations but I am in the camp that doesn't think it's legitimate. The only place that could be done is an abandoned airport runway. Also, if there is an actual relearn process, shouldn't it be on BMW to perform it before handing it back to the owner?

[TunafishE93]

I would take it back to dealer and have them fix their problem..

[Moisture]

Second that^

[svagusta]

So my car has basically been sitting all year but finally getting back to trying to diagnose this. Took it back to dealer, they won't do anything about it since it doesnt happen when car is in factory settings and blame it on my tune that was working fine before. Took it to my indy to double check the work on the transmission, they did not find any leaks or problems with mech seal/adapter or the plug/pins and they also say it's my tune.

Got INPA setup and am now able to pull codes from all modules which actually isnt providing much additional insight. This is the complete list of faults and every single one is pointing to data missing from the trans. No EGS fault codes present.

Cant figure out why MHD Stage 0 has no problems, but any of my custom tunes that worked fine before, now have this problem come up. Dealer did update software on the car, but most ppl have said software updates helped solve problems, not create new problems.

DME
3BDD No message (EGS torque request, 0xB5), DME receiver, EGS transmitter
3BE1 No message (transmission data, 0xBA), DME receiver, DKG transmitter, EGS
3BD8 No message (transmission data 2. 0x1A2), DME receiver, EGS transmitter
CD8F DME: PT-CAN communication fault

DSC
D357 No message (steering angle 1F5)?? Is this the correct description?

KOMBI
A3AA No message from transmission control unit, receiver KOMBI, transmitter ACC

[Tunafish]

Ok first.. Stock doesnt give you any problems? You can do pulls with no codes?.. Thats step one.. If issue is there in stock configuration stop putting a tune on it and fix the issue.. Probably the unit deal replaced, or connection not seated.. What you gap measure at?

If in stock you dont have a issue than which tune are throwing codes.. We need to know which tune is causing the issue to help..

[Pladi]

Originally Posted by svagusta

So my car has basically been sitting all year but finally getting back to trying to diagnose this. Took it back to dealer, they won't do anything about it since it doesnt happen when car is in factory settings and blame it on my tune that was working fine before. Took it to my indy to double check the work on the transmission, they did not find any leaks or problems with mech seal/adapter or the plug/pins and they also say it's my tune.

Got INPA setup and am now able to pull codes from all modules which actually isnt providing much additional insight. This is the complete list of faults and every single one is pointing to data missing from the trans. No EGS fault codes present.

Cant figure out why MHD Stage 0 has no problems, but any of my custom tunes that worked fine before, now have this problem come up. Dealer did update software on the car, but most ppl have said software updates helped solve problems, not create new problems.

DME
3BDD No message (EGS torque request, 0xB5), DME receiver, EGS transmitter
3BE1 No message (transmission data, 0xBA), DME receiver, DKG transmitter, EGS
3BD8 No message (transmission data 2. 0x1A2), DME receiver, EGS transmitter
CD8F DME: PT-CAN communication fault

DSC
D357 No message (steering angle 1F5)?? Is this the correct description?

KOMBI
A3AA No message from transmission control unit, receiver KOMBI, transmitter ACC

What i would do is this.

Remove all 3rd party tuning software for mhd and xHP.

Not juat flash stock. Fully remove mhd and xHP.

Then re flash a known software package like PPK or any othet with inpa/ista.


THEN go back to tuning.

[svagusta]

Originally Posted by Tunafish

Ok first.. Stock doesnt give you any problems? You can do pulls with no codes?.. Thats step one.. If issue is there in stock configuration stop putting a tune on it and fix the issue.. Probably the unit deal replaced, or connection not seated.. What you gap measure at?

If in stock you dont have a issue than which tune are throwing codes.. We need to know which tune is causing the issue to help..

Shop said the gap was the correct 2 or 3mm - forget which one it is.

--Factory DME settings will not reproduce the issue, but I'm katless and have 3.5bar tmap which OEM DME does not like so it wont allow boost to build at these settings - so not sure if this is an apples to apples comparison, as car doesnt really make any power here.

--MHD Stage 0 lets car out of limp mode since it can account for katless and N20 tmap, and I am not able to reproduce the issue here, can go WOT no faults.

--Custom MHD tune from Twisted Tuning will produce fault codes, but only when hitting relatively high power. I can drive it around town no problem until I mash on it.

Today I started playing around with MHDs option to limit power by gear for the Twisted Tune. I decreased the power to 50% through all gears, no fault codes appear. I can go WOT without any stumbles. I raised it up to about 75% and started having issues again at WOT.

This is leading me to wonder if its DSC/traction related, but there are no helpful fault codes being thrown - everything is pointing to missing info from the transmission...

[svagusta]

Originally Posted by Pladi

What i would do is this.

Remove all 3rd party tuning software for mhd and xHP.

Not juat flash stock. Fully remove mhd and xHP.

Then re flash a known software package like PPK or any othet with inpa/ista.


THEN go back to tuning.

I'm very new to INPA - really only know how to read error codes and have not been able to get ISTA setup so this may be beyond me. I will see what I can learn about flashing PPK.

MHD and XHP were completely removed as of last week. I am trying to add back one at a time to isolate the issue. I also replaced my battery this weekend, coded and registered it as my previous one had sulfated and was almost 5 yrs old anyway. Was hoping this might be the source of electrical gremlins, but no luck.

I'm not opposed to trying tuning methods other than MHD if it would help me know where to point the finger but won't lie I am pretty invested in MHD - 4 custom tunes that all worked fine before that I'm definitely not ready to consider trash.

[svagusta]

So, I reached out to MHD to see if there are any software compatibility issues after dealer update or any issues with MHD version as they had some notes about bench unlock possibly being required (I'm not very clear on this part or why it's needed). But they said that I shouldnt have to worry about it as a 2011 335i should have MEVD172 which does not require bench unlock. I never have any problems flashing so I doubt this is an issue.
But when I pull Identification from INPA I see DME as MEVD176K (part# 8618483) - just want to make sure this is expected?

[Tunafish]

If you didnt have issues before mechatronics than that is where the troubleshooting to start.. Its seems that communication issues are common after replacement.. In the pdf last page there is troubleshooting steps for just this issue ...

My guess would be push back pin.. But you will have to go thru the steps to find out..

[svagusta]

Originally Posted by Tunafish

If you didnt have issues before mechatronics than that is where the troubleshooting to start.. Its seems that communication issues are common after replacement.. In the pdf last page there is troubleshooting steps for just this issue ...

My guess would be push back pin.. But you will have to go thru the steps to find out..

Yeah, I agree and this is what I had my indy doublecheck. They reported that fluid level, plug/pins and sleeve/gap all looked good. The only thing that I didnt discuss with them was the voltage test. But I would also guess that if there was a voltage issue, I would have more problems than I'm experiencing.

I've never used this shop before but they have a good reputation as far as I can tell and foreman seems very knowledgeable about this trans, however they were very reluctant to drop the pan and take a look - they really did not think they would find a problem.

I'm going to keep going through a few more scenarios to see if there might be more conditions where I can replicate the issue, but may end up getting another shop to take a look as well and see if they find anything different.

[svagusta]

I've tested a few more scenarios as I try to narrow down if this is a software or hardware issue, since codes are not helpful.
My observations have been that problems tend to show up during wheel spin situations, so my thinking is it's either
---Hardware: physical forces/car shaking briefly jostles a connection loose.
---Software: hitting a certain power level causes either DME or EGS a problem.

So I went back to Stg 0 with a 1st gear launch and was able to spin the wheels without fault codes/limp mode, but it still botched the 1-2 shift and decided to go straight to 4th. This would have to be software right? I dont see how my trans could all of the sudden slip so badly and EGS has not thrown a single code this entire time. Codes only ever come from DME.

Think I'll unflash everything again and reset trans adaptations this weekend, as I'm pretty sure that got hosed by the dealer too.

[crosby.109@osu.edu]

Did you ever resolve this issue? I have same exact problem but started randomly out of no where (didn’t replace anything). I had custom tune through MHD from Twisted Tuning and ended up reverting to a stage 2+ which resolved the issue for a day but now same thing. This has to be something software related as you mentioned, hoping you have the answer!

[svagusta]

Originally Posted by crosby.109@osu.edu

Did you ever resolve this issue? I have same exact problem but started randomly out of no where (didn’t replace anything). I had custom tune through MHD from Twisted Tuning and ended up reverting to a stage 2+ which resolved the issue for a day but now same thing. This has to be something software related as you mentioned, hoping you have the answer!

No, this is my second car and it's just been sitting since COVID. I haven't tried any further diagnosis or made any progress, but found a good indy that said it could be anything but are up to the challenge, so hopefully I can get it over to them soon.

Are you getting the same DME Codes?

Keep me posted if you find anything out. I'll do the same.

[svagusta]

I hate when I came across unresolved threads when researching this problem, so just putting a final update for the interwebs.

The issue seems to have resolved itself somehow - I believe it was software updates pushed out by MHD & xHP.

The car sat most of 2020 and 2021 only being driven occasionally. And then after many months of not trying anymore I decided to attempt to troubleshoot again. There were now updates to MHD & xHP software - which is what I believe fixed the issue. I reflashed both DME and Trans (which I had done many times before & even reached out to both support teams to ask about software compatibility issues) but for whatever reason it seemed to work this time.

Can spin the tires and pull hard without any missed shifts or erratic behavior. I'm happy to have my car back again.

[wheela]

Glad you got it resolved, and thanks for following up with the solution!