[Nixer]

Update: As @maksymw sait, it was the eeprom. Thanks @maksymw for all the help in guiding me flash the eeprom you created. I had to flash just the eeprom and re-encode the DME. Everything is back to normal.


My 535i has been in limp mode for the past few months and I have not been able to figure out what's wrong. Local indy shop has no clue either and suggesting that it could be the DME.

Car idles fine, compression test showed 193-203 range and smoke test doesn't show any leaks. Car drives find up to 15 mph and as soon as it shifts automatically to 3rd gear, loses power completely and start to shudder when accelerating. I tried to manually put the car in 2nd gear and same behavior above a certain speed, usually around 15 mph. There is no engine/transmission fault codes. The only code I have is for water vale and seat standardization that I am planning to take care of later.

Removed the catalytic converted and tried with catless downpipe, but issue persists. Car previously had MHD state 2 + pump gas tune. We unfortunately no longer have access to the school email that was used to purchase MHD license. I've already contacted MHD, but the only option is buying a new license.

Just to make sure the DME is stock, we used esys to flash the car back to stock. Indy shop is saying that the DME still has some MHD tune in eeprom or somewhere so the only option is getting a new DME. They can't find any mechanical issues with the car.

I was able to complete every test in ISTA successfully. Every module in the car is responding in ISTA and we upgraded software in all available modules via ISTA without any issues. Lower pressure fuel is 50 psi and high pressure shows 80 bar. DME and EGS adaptations have been reset.

I can't figure out what's wrong. I can tow it to a dealer 40 miles away but wanted to get some help here first.

I am based out of Dallas, TX, USA.

Does MHD tune modify DME's EEPROM or any part of the DME that can't be reset to stock via esys? I see no physical damage to the DME and the wiring looks fine.

Apologize for the long post but I wanted to share as much info as possible for anyone that could help out!!

Datalog links in the attachement

[jaki]

So have You flashed DME with AOS ISTA to stock?
Better to flash complete car with ISTA, not esys.

[Node]

Your post is NOT too long, it is MUCH too short.

You should EXPLAIN which log contains what. Now we need to spend SIGNIFICANT time to figure out ourselves even to BEGIN comprehending what is in the logs...

Then the problem with like 90% of data in the log ARE ZEROES!!! No fuel pressure data, boost data are ALLMOST all ZEROES too. Does that mean your boost is faulty or just data logger issue??? I have no idea. So have no idea too what you used to make logs, but its TOTAL CRAP. Use ISTA expert mode and make PROPER logs.

From like 5 or 6 somewhat useful numbers which are NOT zeroes IMHO you could try disconnecting air mass sensor... On one sheet you have >100kg/h air mass and some boost pressure just revving (what looks like at a standstill), and then puny 44kg/h MAX with NO boost at all while in 3rd gear... But then you pressed accelerator pedal JUST to 18% while in 3rd, so who knows...

So if mas air flow disconnect does hot help, make PROPER logs and PRESS THE GAS seriously while doing that in 3rd!

---

P.S. Usually flashing removes tuning fully.

[maksymw]

I had the same problem When use e-sys, you write only flash, it does not touch the eeprom. I tried to flash the ecu again with e-sys, it didn't help. I unplugged the ABS sensors and tried everything. I finally solved the problem. The problem was a faulty eeprom dump. I write the original eeprom from another ECU, changed the ISN and VIN. The car came back to life

Here good eeprom from f10 n55, pass pm:

dump.txt
File Type:
Downloaded:	7 times
Size:	73 bytes

[Nixer]

Your post is NOT too long, it is MUCH too short.

You should EXPLAIN which log contains what. Now we need to spend SIGNIFICANT time to figure out ourselves even to BEGIN comprehending what is in the logs...

Then the problem with like 90% of data in the log ARE ZEROES!!! No fuel pressure data, boost data are ALLMOST all ZEROES too. Does that mean your boost is faulty or just data logger issue??? I have no idea. So have no idea too what you used to make logs, but its TOTAL CRAP. Use ISTA expert mode and make PROPER logs.

From like 5 or 6 somewhat useful numbers which are NOT zeroes IMHO you could try disconnecting air mass sensor... On one sheet you have >100kg/h air mass and some boost pressure just revving (what looks like at a standstill), and then puny 44kg/h MAX with NO boost at all while in 3rd gear... But then you pressed accelerator pedal JUST to 18% while in 3rd, so who knows...

So if mas air flow disconnect does hot help, make PROPER logs and PRESS THE GAS seriously while doing that in 3rd!

---

P.S. Usually flashing removes tuning fully.

Thanks for the suggestions. I am using bimmerlink to capture logs and some parameters are not recorded/available so reports zero. I will try ISTA expert mode and make another log with wide open throttle. I've never tried expert mode in ISTA+ before. How do I enable it? I tried searching but haven't found anything useful yet.

[Node]

Given maksymw had experience with broken eeprom data you could try his suggestion. I have not seen cases where tuning can't be removed by flashing, but there may be such cases...

[Vtech_BR]

Probably, reading your report of having already updated the dme, it is almost certain that you have a problem with incorrect power class coding in the CAS or even a CKS error in the CAS module

[Nixer]

I had the same problem When use e-sys, you write only flash, it does not touch the eeprom. I tried to flash the ecu again with e-sys, it didn't help. I unplugged the ABS sensors and tried everything. I finally solved the problem. The problem was a faulty eeprom dump. I write the original eeprom from another ECU, changed the ISN and VIN. The car came back to life

Here good eeprom from f10 n55, pass pm:

Thanks. Sent you a PM for the password.
When you say unlplugged the ABS sensors, you mean all the 4 wheel speed sensors? I get correct speed info from all 4 but can't hurt to try it.

---

Probably, reading your report of having already updated the dme, it is almost certain that you have a problem with incorrect power class coding in the CAS or even a CKS error in the CAS module

I have updated all other modules to the latest, except CAS. Should I go ahead and update the CAS module also via ISTA or esys? Any precautions I should take when updating CAS?

[maksymw]

Power class will not cause a case like this.. Don't take into account my suggestion about ABS sensors because I have tried every way to find out why the car is going to a certain speed and I don't want to accelerate even 1 mph more. I am 100% sure that after uploading the eeprom the car will be repaired. If you want, you can send me your ISN and VIN by PM and I will convert the eeprom for your car.

[Nixer]

I don't see the expert mode option in ISTA+ for my car. Not sure why. So I did another log with bimmerlink. Not sure if there is enough information to make a determination. Please take a look and let me know if you find anything interesting.

If there is another app I can use to log better data, please suggest.