Comprehensive MSS54/MSS54HP DME Information

[elborikua]

New guy here. Swapping an S54 into my 1978 Volvo (dont hate me). Perusing this thread, I believe I might have bit more than what I can chew. We shall see.

[karter16]

hey guys,

i recently started with the mss54hp disassemlby in idapro.
So as first step i searched for the locations where the can-registers are setup, but i'm already stuck at this point.
I can see that many other registers are set but i cannot find the can-addressspace.
I'm searching for addresses for can upwards 0xFFF080 - 0xFFF0A6 as stated in the MC68336/376 ref.manual.

Can you help me getting started and find the right initial spots to look at?

regards
chris

Appreciate this is a very old post but thought it worth noting as may be useful to others.

The MSS54 is not based on the MC68376, it appears to be a custom variant of the MC68336 which does not have the TouCAN module (among a few other things). The MSS54 CANbus implementation is a different/custom implementation unrelated to TouCAN.

[S54_DNA]

just pm'd you.
2003 M3 6 -speed, non HP

[ppm008]

tell me your model, model year and msss54 version, HP or not

[S54_DNA]

Hi, is there any way to know which program version (Cal ID) is the correct one to use for a certain year or by VIN? I do not know what the original was as it was flashed with a tune. When flashed back to a stock tune, apparently it is not the correct one according to the ref. So I don't know if it's the wrong version that they're having issue with? And the ref won't tell me exactly what they want.

[karter16]

This map is called KF_RG_M and is not used in standard CSL prog

Thanks for that, much appreciated :-) - curious what reference material you have with that information in it?

[ppm008]

Note: the below question relates to the 0401 CSL binary.

Does anyone have any information on the 16x12 table at 0x8E42A (table pointer reference in Master binary program code, start of data points when viewing the table in TunerPro is 0xe464). x axis is engine speed and y axis is relative fill, I do not yet know the units of the cell values. I should be able to figure it out in more time by continuing with disassembly, but wondered if anyone else has any info on this?

This map is called KF_RG_M and is not used in standard CSL prog

[bmwfnatic]

Im right at the cusp i think, do we now when exactly on that month?
My car has 2003-09-04 manufacture date, since its earlier in that month, I'm assuming its a non-hp

Even if the catalog says one thing, if it’s that close it’s not always accurate. Just check with INPA or physically by looking at the sticker on the DME.

[elrichmeister]

Should be manufacturing date after 09/2003.

Im right at the cusp i think, do we now when exactly on that month?
My car has 2003-09-04 manufacture date, since its earlier in that month, I'm assuming its a non-hp

[bmwfnatic]

Pardon my ignorance but ... is there an easy way to determine whether I have MSS54 or MSS54HP such as VIN later than XXXX? Would like to do an MSSMapper tune with a reduced redline (~7k RPM)

Should be manufacturing date after 09/2003.

[BTB]

Pardon my ignorance but ... is there an easy way to determine whether I have MSS54 or MSS54HP such as VIN later than XXXX? Would like to do an MSSMapper tune with a reduced redline (~7k RPM)

[karter16]

Note: the below question relates to the 0401 CSL binary.

Does anyone have any information on the 16x12 table at 0x8E42A (table pointer reference in Master binary program code, start of data points when viewing the table in TunerPro is 0xe464). x axis is engine speed and y axis is relative fill, I do not yet know the units of the cell values. I should be able to figure it out in more time by continuing with disassembly, but wondered if anyone else has any info on this?

[sapote]

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.

The ambient pressure sensor is used only for CSL as the DME needs to interpret the MAP sensor in the CSL intake, and so for non-CSL I don't think it's matter. No?

[sapote]

https://raw.githubusercontent.com/za...en_Deutsch.pdf

I wonder how it got there

Wow, this document seems to be a detail DME control software block diagram and theory! All we need is the "C" source code.
Or have anyone used a compiler or assemble to convert the binary file to 68376 assembly codes? C source is perfect but I am happy to work with assembly codes.

[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