Comprehensive MSS54/MSS54HP DME Information

[R3VM3UP]

I am having a hard time understanding the maps shown in the first post on this thread. One of the first steps of EFI tuning is to calibrate the volumetric efficiency table (for example, when fitting a CSL airbox or more aggressive camshafts, it increases the VE and the air-fuel ratio gets too lean, and a VE table calibration can remedy this) anyone knows how pro tuners do this on our MSS54/HP ??

Non CSL software uses the MAF to essentially 'directly' measure airflow. The CSL runs primarily alpha N with some sort of compensation from the MAP sensor on the air rail. I'd imagine the pulsations in the MAP rail require significant filtering due to the small volume of the rail and proximity to the ports, so it cannot be used as the primary air charge estimation method. The main alpha-N VE table is KF_RF_N_AQ_REL, which is a function of engine speed and relative throttle opening.

KF = map
RF = relative filling
N = engine speed
AQ_REL = relative cross sectional opening

[dreamdrivedrift]

Just wanted to say: THANK YOU! I was able to do something (simple) and fix my sport mode memory (which was set to always on) with the help of this thread and multiple others. Really appreciate the work of the community in creating and documenting these resources, all in their spare time. They are invaluable; and I learned a lot in the process.

[E46m3zcp]

I am having a hard time understanding the maps shown in the first post on this thread. One of the first steps of EFI tuning is to calibrate the volumetric efficiency table (for example, when fitting a CSL airbox or more aggressive camshafts, it increases the VE and the air-fuel ratio gets too lean, and a VE table calibration can remedy this) anyone knows how pro tuners do this on our MSS54/HP ??

[M3Dude]

Hi guys,
I am trying to code out the SAP on my E46 M3, is there a write-up anywhere that can be followed on a step-by-step basis? Also, does anyone know what the code needs to be changed to so the system is no longer searching for it? I couldn't find it in the tables...

[heinzboehmer]

I have a line on an MSS54 but need an MSS54HP. Before I bite the bullet I need to know for sure this conversion is as easy as stated above. Can anyone confirm that this information is correct? Just replace the PROM chips?

There's also some resistors: https://nam3forum.com/forums/forum/s...=2582#post2582

The pressure sensor is different too, so you either have to scale it differently in software or swap out the hardware.

[cek]

My understand is the MSS54 vs MSS54HP only difference is the flash PROM chips, 256KB vs 512KB. So to convert the MSS54 board to MSS54HP, one needs to remove the 2 chips (512KB) from a S54HP then read and save the files using something like the chip programmer below, then program the files into the two new chips (512K), i.e. AM29F400BB-60SC
from https://www.mouser.com/ProductDetail...W34bxMGA%3D%3D
then solder the new programmed chips back to the S54 DME board and now it become a S54HP DME.
Have anyone done this before?

I have a line on an MSS54 but need an MSS54HP. Before I bite the bullet I need to know for sure this conversion is as easy as stated above. Can anyone confirm that this information is correct? Just replace the PROM chips?

[R3Z3N]

^Translated to English via Google Machine Learning

[sda2]

https://raw.githubusercontent.com/zarboz/BMW-XDFs/master/PDF/Siemens_MSS54_Funktionsrahmen_Deutsch.pdf

I wonder how it got there

[gixxer]

To anyone tracking their DME information:

Anyone has this hardware number MSS54HP variant? If so, then what model year is the car?


DME/ECU Type: MSS54HP
DME Version: 211323002701-J469
Transmission Type: 6 Speed Manual
Chassis: E46
Hardware Number: 7842981


Thanks.

[Chris_de]

Is there a disassembly publically available with the maps and routines already defined? I'm thinking about starting something like this, so that additional function could be implemented or disabled.

For example, the flash counter could propably be disabled when skipping/modifiying the funcrtion that does the lookup or write.

I know C167 quite well, but from what Ive learned with MS45 and ME9, MPC is not that complicated to work with, because it has a better decompilation implement in IDA or Ghidra.

I dont know such a thing, I want also to start with this process, tools are available but i failed finding a good starting point..

[sda2]

Is there a disassembly publically available with the maps and routines already defined? I'm thinking about starting something like this, so that additional function could be implemented or disabled.

For example, the flash counter could propably be disabled when skipping/modifiying the funcrtion that does the lookup or write.

I know C167 quite well, but from what Ive learned with MS45 and ME9, MPC is not that complicated to work with, because it has a better decompilation implement in IDA or Ghidra.

[rjskalet]

Does anyone know the hex location for the ISN to clear out so I can realign a dme with the ews. It was in the old thread but I can’t find a cached version of it unfortunately.

[HanSooloo]

I have an 04 M3 with manufacture date of 11/03, so I am guessing/hoping that it has an MSS54HP DME. Trying to understand what is different between having a standard boot loader (stock that came with the car) versus having a CSL boot loader.

[skristedja]

Do these maps look right? This is from a 0401 csl tune hosted this github modified for stock US m3 cams: https://github.com/YulCmr/MSS54_HP_C...info_gathering

Load base map



Full throttle map

[Tchleung]

Odd question, I've been running the same software for quite some time(can't recall the version #) but I've had obd2 scanner and readers always working fine but somewhere along the line of my multiple revisions of my tune and refreshing, my OBD port no longer reports data to and scanners or gauges. It connects to the Bluetooth modules etc as there is power but won't connect to the car. I can tune and connect and read codes via INPA etc but regular scanners no. I know early 2000s there was that encrypted data stream recall. Mine is an 02 but indont know why it would stop working randomly when I haven't changed software versions in a long time. I'm still using a euro based software, same as I have been using for many years without issues. I feel it's almost like the same issue Awron had with their vent gauge where they say it doesn't work on some E46 M3's with a tune and Euro M3's.

Any ideas??