Some pics @ http://volvospeed.com/vs_forum/topic/159506-tuners-rejoice-free-tuning-for-m44/page-3 -- I can take some additional ones if those are not sufficient to get part numbers off. 

- Both M4.3 and M4.4 must be in boot loader mode to read/write the flash, for both, applying voltage to pin B8 before powering up the ECU accomplishes this
- Both M4.3 and M4.4 are programmed via 9600 baud K-line, however M4.3 uses pin B5 and M4.4 uses pin B36 (the later shared with OBD-II).  On M4.3 cars, pin B5 connects to pin 3 of the OBD-II port.  On M4.4 cars, B36 connects to OBD-II pin 7, the normal pin for OBD-II K-line data, and provides both the programming interface as well as OBD-II and proprietary diagnostics protocols (VST, McMess)
- M4.4 has a split address flash arrangement (128kbye flash chip on a 16-bit address bus, a GPIO pin is used to toggle the MSB) and can't be read via serial as there's no way to toggle the GPIO pin while in bootloader mode
- M4.3 uses a 64kbyte flash chip and can be read completely across the serial interface.
- To program in-car via the OBD-II port, one has to somehow get voltage to pin B8.  For M4.3, the OBD-II cable needs to be wired to use pin 3 instead of pin 7 for data.  For M4.4, voltage must be at least 14v, for whatever reason, so most people connect a battery charger when flashing to raise the voltage on M4.4 cars.

Personally I just program them on the bench.  It's less trouble, IMHO.  M4.3/M4.4 cars have the ECU in a basket under the hood and it's very easy to remove/reinstall, unlike some cars which have the ECUs in difficult to access locations, such as tucked behind the dash, etc.  I have two ECUs and simply alternate, pulling one to replace with the other and bringing the other one back to the bench for the next round of tweaks. 

Hi sorry to take this thread from dead, but I was reading and studying and found this info.
Hammersword do you mean that we can use a factor of 10.24 to convert any ms/Umdr Load axis to absolute pressure in "mbars"? X, Y or Z axis??? Also does it can be used for any map, I mean ignition, fueling or boost or just boost maps?

Thanks a lot for elaborate that. I understand your comment. Then for older Motronic M38x & M59x, that Load (ms/Umdr) is directly related to engine torque, but is it the same measure that we can log using VAGCOM as Load (ms)??
Finally many people try to find a relationship between Load (ms) and Load (%) or Load (pressure) as a comparation for tuning purposes. That is reason of my previous question about convert or just transform Load (ms/Umdr) in other unit like pressure for the typical RPM/MAP Relative Pressure/AFR table. That give me to my other question, what is the difference as torque, boost or engine load itself found as X or Y axis or as a result in a Z axis table?

Could you care to tell a little more about how decreasing or increasing advance is going to affect load being injection time to reach lambda 1?

Don't overcomplicate things. In this ECU: LOAD = MAFLIN(MAF_VOLTAGE)/RPM*K
Done. None of your ignition advance or torque yadda yadda has anything to do with it.

As for pressure - this ECU does not know what pressure is. It pulses the N75 valve to reach req. filling, it uses feedback control from the MAF instead of using a pressure sensor. Really damn simple system, works great as long as your MAF is big enough, not so great if you exceed it's size.

Anything decent power you have to decalibrate load anyway, as it just goes to FF. This ECU is best treated with the "garbage in, garbage out" method. Never fails to work, and not any different from tuning any other old motronic.

Yes, I know all this, but this has nothing to do with this ECU.
The torque model, effective ignition angle and all that came in ME7.

M3.8 and older have no notion of torque, there is only cylinder filling (load). What you do with that cylinder filling is up to you.

Not used for anything really important.

allmost forget !! Indeed ECU did´t translate load to torque, and the cause is just what you said (there is no torque model as ME7)...ECU can´t know what is the detrimental loss with lower/higher advance, AFR... or even with elevation or IAT (there is correction load tables, correct requested load to keep the same torque output).

We are agreeing in everything...