Comprehensive MSS54/MSS54HP DME Information

[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.

[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]

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.

[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

[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?

[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.

[ppm008]

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

[S54_DNA]

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

[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.

[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.

[bbsuhree]

For anyone who's dealing with CVN/CAL ID song and dance... See this: https://github.com/saildot4k/MSS54-XDFs/pull/19

[nesterkyn]

I have a tricky hardware question, unsure if anyone can help me or if it's just going to require a lot of digging/testing. I have a Z3 with an S54 swapped into it, big thanks to R3Z3N for the superb GitHub repo, and it was having some strange issues when I first did the swap.

The symptoms: When the car is put in accessory mode, the throttle works, and the actuator functions perfectly. However, when I crank the starter, even if the car does not start, the throttle actuator stops working until I power cycle the system again. If the car starts, it just idles weirdly with no throttle control, with the actuator not responding to pedal movement. Only a TPS position code would come up on the DME, no other fault codes. The actuator and TPS's are new, and the problem was eventually resolved by replacing the DME (the car now runs fine, no codes).

Now I have the old DME pulled apart on my desk and am tracing the connections back from the throttle actuator connectors on X60001 (pins 2 and 9). I traced them back to an H-bridge motor driver IC (https://www.nxp.com/docs/en/data-sheet/MC33186.pdf) and traced the signals further back to a quad XOR IC (https://www.onsemi.com/pdf/datasheet/mm74hc86-d.pdf), from there the signals go back to one of the main processors.

Since I have isolated the issue to be internal to the DME, are there any hopes of repairing it? No fried components, no broken diodes from what I have measured so far. I would love a schematic for the MSS54 to keep digging, but I can't find one. My worst case for this scenario is that it's not a failed component in the throttle actuator control circuit and that this 'No throttle control' condition is the DME's response to an issue with sme other circuit on the board, or even an internal processor fault. Any advice would be appreciated.

[karter16]

Only a TPS position code would come up on the DME, no other fault codes.

Exactly which TPS code/s was it. I can have a look at the exact DME conditions that trigger it, may or may not help narrow things down at all.

[nextelbuddy]

I have a tricky hardware question, unsure if anyone can help me or if it's just going to require a lot of digging/testing. I have a Z3 with an S54 swapped into it, big thanks to R3Z3N for the superb GitHub repo, and it was having some strange issues when I first did the swap.

The symptoms: When the car is put in accessory mode, the throttle works, and the actuator functions perfectly. However, when I crank the starter, even if the car does not start, the throttle actuator stops working until I power cycle the system again. If the car starts, it just idles weirdly with no throttle control, with the actuator not responding to pedal movement. Only a TPS position code would come up on the DME, no other fault codes. The actuator and TPS's are new, and the problem was eventually resolved by replacing the DME (the car now runs fine, no codes).

Now I have the old DME pulled apart on my desk and am tracing the connections back from the throttle actuator connectors on X60001 (pins 2 and 9). I traced them back to an H-bridge motor driver IC (https://www.nxp.com/docs/en/data-sheet/MC33186.pdf) and traced the signals further back to a quad XOR IC (https://www.onsemi.com/pdf/datasheet/mm74hc86-d.pdf), from there the signals go back to one of the main processors.

Since I have isolated the issue to be internal to the DME, are there any hopes of repairing it? No fried components, no broken diodes from what I have measured so far. I would love a schematic for the MSS54 to keep digging, but I can't find one. My worst case for this scenario is that it's not a failed component in the throttle actuator control circuit and that this 'No throttle control' condition is the DME's response to an issue with sme other circuit on the board, or even an internal processor fault. Any advice would be appreciated.

is it possible there is a fried or burned trace somewhere on the PCB between the actuator IC and the CPU? they can be hard to see sometimes.

the pins on x60001 are just for power to the actuator IC

if you wire up a pedal to x60004 on your bench for input, you should be able to test voltage output to the actuator on x60003 pins 10 and 20 power and ground respectively.

maybe replacing the H bridge itself for the actuator.


was this a conversion DME from mss54 to HP? did it always work before and just stop? or has it never worked?

if its conversion and hasnt worked since conversion, possible related issue to any bridged pins on the eeprom replacements? or possible bridged pins on the CPU since they are right near the eeproms? maybe add some flux to the legs of the CPU and try reflowing solder using drag technique on your flat tipped iron and see if that releases anything



i recently converted a ZHP coding index 8 cluster to full m3 cluster by adding all the LED and resistors from a dead M3 board and everything worked in a cluster test but the Oil temp did not work in an M3. still registered as fuel econ. despite the CPUs between clusters being the same, the firmware on them clearly want, i removed the CPU from a dead M3 board and soldered it to the ZHP coding index 8 board and everything worked BUT speedo needle was being wonky and not sweeping but instead just bouncing back and forth.. could find nothing wrong visually but decided to just reflow solder on all legs of the cpu repeatedly thinking maybe there was a bridge behind the legs on the pads i couldnt see and sure enough that did it. now the cluster fully works as an M3 cluster with oil temp and all needles function.

[nesterkyn]

Interesting, I will try to reflow some of the components and see if that works. I am planning to stop by the junk yard and grab a pedal assembly and some DME connector pigtails to wire up a test harness on the bench, so I will update when that happens.

The DME that has this issue came with the engine I swapped into my Z3 from the factory, I pulled everything from a 2002 M3 SMG vert (as you do) and the owner mentioned that after a hot track day the car went into this type of limp mode (no throttle actuator movement) and would not come out. He replaced the throttle actuator motor and rear TPS that comes with it to no avail. To be clear the engine responded to throttle input by adjusting the idle control circuit, the classic throttle limp mode, but even before I pulled the engine the throttle flaps were not moving while the engine was running. This might indicate that the DME itself was heated and vibrated excessively, so a reflow is a good place to start.

As for codes, the following codes would persistently reappear after clearing:
118 - freq 2, "Electronic Throttle Potentiometer Bank 1"
107 - freq 20, "Electronic Throttle Self Test"
119 - freq 1, "Electronic Throttle Potentiometer Bank 2"
137 - freq 1, No description in BMWLogger

Also, I have traced every pin coming from the H-Bridge except pin 8, COD, which according to the datasheet controls the error reset behavior and should be tied to either VCC or GND. Maybe this is my bad connection, more investigation needed.